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A new turtle taxon (Podocnemidoidea, Bothremydidae) reveals the oldest known dispersal event of the crown Pleurodira from Gondwana to Laurasia
Abstract
Pan-Pleurodira is one of the two clades of extant turtles (i.e. Testudines). Its crown group, Pleurodira, has a Gondwanan origin being known from the Barremian. Cretaceous turtle fauna of Gondwana was composed almost exclusively of pleurodires. Extant pleurodires live in relatively warm regions, with a geographical distribution restricted to tropical regions that were part of Gondwana. Although pleurodires were originally freshwater forms, some clades have adapted to a nearshore marine lifestyle, which contributed to their dispersal. However, few lineages of Pleurodira reached Laurasian regions and no representatives have so far been described from the pre-Santonian of Laurasia, where the continental and coastal Cretaceous faunas of turtles consist of clades exclusive to this region. A new turtle, Algorachelus peregrinus gen. et sp. nov., is described here from the southern Laurasian Cenomanian site of Algora in Spain. Numerous remains, including a skull and well-preserved postcranial specimens, are attributed to this species. The abundant shell elements, much more numerous than those known in most members of pleurodiran clade Bothremydidae, allow its variability to be studied. The new taxon represents the oldest evidence of the occurrence of Pleurodira in Laurasia, and is the oldest genus of the abundant and diverse Bothremydodda so far described. Factors such as the relatively high Cenomanian temperatures, the adaptation of this Gondwanan clade to coastal environments, and the geographical proximity between the two landmasses may have contributed to its dispersal. This finding shows that the first dispersals of Pleurodira from Gondwana to Laurasia occurred much earlier than previously thought. http://zoobank.org/urn:lsid:zoobank.org:pub:8FD358A5-53BD-4308-828A-AC6802184185 © The Trustees of the Natural History Museum, London 2016. All rights reserved.
... The bothremydids may have lived in different environments, indicating by the recording of their remnants from several sediments with diverse paleoenvironments, such as freshwater and littoral marine environments. The secondary adaptation to littoral marine environments gave them the ability for dispersal between different continents, the origin of all or most of the Bothremydidae lineages being located in the southern hemisphere, but most of them also reaching the northern hemisphere [14,15]. The bothremydid turtles attained a great level of variety and vast range throughout the Cretaceous and Paleogene, and are especially well registered throughout the Late Cretaceous, from the Cenomanian to the Maastrichtian [16,17]. ...
... Characters such as the first pair of costal plates approximately twice as long as the second one; the presence of fewer than eight neural plates, resulting in the medial contact with the last pairs of costals; axillary buttresses reaching the third peripherals; the presence of relatively small lateral mesoplastra; and absence of a cervical scute, allow the identification of the specimen studied here as a member of Bothremydidae [15,17,[37][38][39][40]. It can be attributed to Bothremydidae by the presence of a relatively short and wide anterior plastral lobe, shared with the members of Bothremydini, but not with those of its sister group Taphrosphini, and the absence of overlap of the pectoral scutes on the epiplastron [15,17]. ...
... Characters such as the first pair of costal plates approximately twice as long as the second one; the presence of fewer than eight neural plates, resulting in the medial contact with the last pairs of costals; axillary buttresses reaching the third peripherals; the presence of relatively small lateral mesoplastra; and absence of a cervical scute, allow the identification of the specimen studied here as a member of Bothremydidae [15,17,[37][38][39][40]. It can be attributed to Bothremydidae by the presence of a relatively short and wide anterior plastral lobe, shared with the members of Bothremydini, but not with those of its sister group Taphrosphini, and the absence of overlap of the pectoral scutes on the epiplastron [15,17]. Within the lineage of Bothremydini, the specimen analyzed here cannot be attributed to any previously defined taxon (see Discussion). ...
The Quseir Formation is an Upper Cretaceous (Campanian) deposit in the Kharga oasis of the Southwestern Desert (Egypt). This formation comprises a clastic sequence of bioturbated mudstone and sandstone intercalations, including rare scattered and fragmented vertebrate remains such as shark teeth, dinosaur remains, and turtle plates. These deposits indicate a supratidal marsh environment. A complete shell of a turtle discovered from the Quseir Formation, at the Kharga oasis, is attributed here to Bothremydini (Pleurodira, Bothremydidae), and determined as a new taxon: Khargachelys caironensis gen. et sp. nov. This form represents the only Bothremydini member currently identified in the Campanian record not only of Egypt but also of North Africa. Therefore, it helps fill the missing evolutionary gap from the Late Cretaceous pleurodires in Egypt and in North Africa.
... The pleurodires Bothremydidae Baur, 1891 constitute the most abundant and diverse clade of turtles for the last part of the Cretaceous record (Campanian and Maastrichtian) in Southwest Europe (Lapparent de Broin 2001;Gaffney et al. 2006;Pérez-García & Ortega 2018). The currently available fossil record suggests that Bothremydidae reached Europe in the early Late Cretaceous, during the Cenomanian, through the oldest documented dispersal event from Gondwana to Laurasia of a lineage of the crown Pleurodira (Pérez-García 2016Pérez-García et al. 2017). The first systematic assessment of the Spanish Upper Cretaceous bothremydid record is part of a study on the turtle fauna from the upper Campanian site of Laño, in Treviño County (Burgos Province, North of Spain) (Lapparent de Broin & Murelaga 1996). ...
... dIstrIbutIon. -Late Campanian to late Maastrichtian of Southern France (identified in the Haute-Garonne Department) and Sorthern and central Spain (known in the Provinces of Burgos, Cuenca and Segovia) (Lapparent de Broin & Murelaga 1996, 1999Laurent et al. 2002;Pérez-García et al. 2010, 2012, 2016. -Member of Foxemydina with the following autapomorphies: carapace rectangular with straight or slightly depressed anterior margin; maximum carapace width in its posterior half; presence of six neurals and, therefore, sagittal contact of the last three pairs of costals; square first pair of marginals, covering more than half the lateral nuchal length. ...
... The availability of abundant material allows plate and scute anomalies to be identified. In fact, anomalies corresponding to both elements are recognized as relatively frequent in other bothremydids represented by several specimens, as reported, among others, for the oldest European form: the Spanish Algorachelus peregrina Pérez-García, 2016. A small supernumerary scute was identified, adjacent to the medial region of the left humero-pectoral sulcus, in the most complete known shell of Iberoccitanemys atlanticum n. comb., from the Spanish site of Lo Hueco, in the Province of Cuenca (see Pérez-García et al. 2010: figs 2.2;2.4;Pérez-García ...
Bothremydidae is the most abundant clade of turtles in the Campanian and Maastrichtian (Upper Cretaceous) fossil record of southwestern Europe. Several members of Foxemydina Gaffney, Tong & Meylan, 2006 are known in an area that includes Southern France and the North-Eastern half of Spain. The problematic ‘Polysternon’ atlanticum is the worst characterized, lacking a diagnosis that allows its specific validity to be confirmed, and whose generic attribution has been recognized as doubtful. Its presence was exclusively proposed in its type locality, the upper Campanian quarry of Laño, in Treviño County (Burgos Province, North of Spain). Despite the fact that knowledge about Bothremydidae has markedly increased after the description of ‘Polysternon’ atlanticum Lapparent de Broin & Murelaga, 1996, no new information about this species has been published since the 1990s. The analysis of abundant unpublished material of the bothremydid from Laño allows us to confirm the validity of this species. As a consequence of this study, it is not only identified in its type locality, but also in other Spanish regions and in the south of France. The diversity of Bothremydidae Baur, 1891 in the Upper Cretaceous of Europe is lower than previously considered. Thus, the species ‘Iberoccitanemys convenarum’ (Laurent, Tong & Claude, 2002), originally defined for the French record, and subsequently also identified in Spain, is identified here as a synonym of the species described in Laño. An emended diagnosis for the upper Campanian to upper Maastrichtian, Iberoccitanemys atlanticum (Lapparent de Broin & Murelaga, 1996) n. comb., is proposed.
... In order to confirm the previous systematic identification of Tartaruscola teodorii as a member of Foxemydina, it was coded in the data matrix of [43], which was similar to that used in the paper where this taxon was defined (i.e., that in [37], based on the data matrix proposed by [24]), but that included a larger number of characters (based on [44]), modifications in the character states of some taxa, and the inclusion of the Spanish Cenomanian (Late Cretaceous) bothremydid Algorachelus peregrina Pérez-García, 2016 [43]. As in [43], Proganochelys quenstedti was considered as the outgroup taxon; the data matrix was analyzed by a heuristic tree search, using TNT 1.5 [45], corresponding to a traditional search with 1000 replications of Wagner trees (using random addition sequences) followed by tree bisection recognition (TBR) as a swapping algorithm, saving 100 trees per replication; implied weighting was performed (K = 3.0); and a pruned strict consensus tree was generated (Bothremys arabicus (Zalmout, Mustafa and Wilson, 2005) [46] being also identified here as a wild card taxon). ...
... In order to confirm the previous systematic identification of Tartaruscola teodorii as a member of Foxemydina, it was coded in the data matrix of [43], which was similar to that used in the paper where this taxon was defined (i.e., that in [37], based on the data matrix proposed by [24]), but that included a larger number of characters (based on [44]), modifications in the character states of some taxa, and the inclusion of the Spanish Cenomanian (Late Cretaceous) bothremydid Algorachelus peregrina Pérez-García, 2016 [43]. As in [43], Proganochelys quenstedti was considered as the outgroup taxon; the data matrix was analyzed by a heuristic tree search, using TNT 1.5 [45], corresponding to a traditional search with 1000 replications of Wagner trees (using random addition sequences) followed by tree bisection recognition (TBR) as a swapping algorithm, saving 100 trees per replication; implied weighting was performed (K = 3.0); and a pruned strict consensus tree was generated (Bothremys arabicus (Zalmout, Mustafa and Wilson, 2005) [46] being also identified here as a wild card taxon). ...
... In order to confirm the previous systematic identification of Tartaruscola teodorii as a member of Foxemydina, it was coded in the data matrix of [43], which was similar to that used in the paper where this taxon was defined (i.e., that in [37], based on the data matrix proposed by [24]), but that included a larger number of characters (based on [44]), modifications in the character states of some taxa, and the inclusion of the Spanish Cenomanian (Late Cretaceous) bothremydid Algorachelus peregrina Pérez-García, 2016 [43]. As in [43], Proganochelys quenstedti was considered as the outgroup taxon; the data matrix was analyzed by a heuristic tree search, using TNT 1.5 [45], corresponding to a traditional search with 1000 replications of Wagner trees (using random addition sequences) followed by tree bisection recognition (TBR) as a swapping algorithm, saving 100 trees per replication; implied weighting was performed (K = 3.0); and a pruned strict consensus tree was generated (Bothremys arabicus (Zalmout, Mustafa and Wilson, 2005) [46] being also identified here as a wild card taxon). ...
Bothremydidae is a successful lineage of pleurodiran turtles that lived from the Cretaceous to the Paleogene, and are found in most continents of both Laurasia and Gondwana. Despite numerous known cranial remains of this clade, no study on the complete neuroanatomical reconstruction of any of its representatives has been published so far. Tartaruscola teodorii is a French lower Eocene member of Foxemydina (Bothremydini), known by two skulls. It is one of the few bothremydids identified in the Cenozoic record of Europe. The present study includes the complete three-dimensional reconstruction of each of the cranial bones of both the holotype and the paratype of T. teodorii, increasing the anatomical information about this species. The virtual reconstruction of its neuroanatomical structures is presented here, including the cranial cavity, nerves, nasal cavity, inner ears, and carotid arteries. This analysis is the first detailed neuroanatomical study performed for a member of Bothremydidae. In addition, the virtual reconstruction of the neuroanatomical structures of some extant taxa belonging to several pleurodiran lineages (Chelidae, Pelomedusidae and Podocnemididae), are also carried out and analyzed, so that the comparative framework for Pleurodira is remarkably improved.
... Bothremydidae is an extinct clade of pelomedusoid turtles and its fossil record, ranging from the Early Cretaceous to the Paleogene at least, has beenidentified in North and South America, Europe, Africa, India, and Madagascar (Gaffney et al., 2006;Romano et al., 2014). Although the first representatives of Bothremydidae were freshwater forms, some lineages were adapted to brackish and marine waters, allowing a dispersion greater than that achieved by most groups of pleurodires (Rabi et al., 2012;P erez-García, 2016P erez-García, , 2018a. ...
... Following previous ideas, Rabi et al. (2012) provided an updated paleobiogeographic assessment for Bothremydini, indicating that the group originated in Gondwana during the Early Cretaceous and only secondarily colonized Europe and North America by African lineages during the Santonian or before. This hypothesis has been recently confirmed by the study of new findings, and it has been acknowledged that the oldest dispersion from Gondwana to Laurasia took place during the Cenomanian (P erez- García, 2016;2018a). ...
... The new taxon is compared to the other forms of Pelomedusoides so far defined in the Cretaceous record, as well as with numerous representatives of the different lineages that are part of this clade. These comparisons have been made considering the information provided by previous authors (Leidy, 1865;Matheron, 1869;Nopcsa, 1931;Carrington da Costa, 1940;Antunes and Broin, 1988;Tong et al., 1998;Laurent et al., 2002;Gaffney et al., 2006;Lehman and Wick, 2010;Cadena et al., 2012;Joyce et al., 2016;P erez-García, 2018a). ...
During the Late Cretaceous, pleurodiran turtles were taxonomically diverse and, inhabited a variety of environments, within a practically worldwide distribution. Among this group, the most widespread at that time was Bothremydidae, which was represented in North America by four taxa: Algorachelus tibert, Chedighaii hutchisoni, Chedighaii barberi, and Bothremys cooki. Nevertheless, the presence of Bothremydidae in Mexico is so far very scarce, and the few reports were recognized at indeterminate generic level and have, not been analyzed in detail. In this paper we describe the first Bothremydini from Mexico, collected in a coal mine in Coahuila in the Late Cretaceous of the Olmos Formation (upper Campanian). The coal mines in this region are known for their paleoflora, but this turtle specimen is the first vertebrate to be notified. This specimen displays a unique combination of characters that allows its attribution to a new representative, Palauchelys montellanoi gen. et sp. nov., thus expanding knowledge about the diversity of this group in the American Cretaceous record.
... . Bothremys is currently restricted to four species, distributed between the Santonian and the early Eocene: the Santonian Bothremys arabicus, the Campanian and Maastrichtian Bothremys cooki, the lower Palaeocene (Danian) Bothremys maghrebiana, and the lower Eocene (Ypresian) Bothremys kellyi (Gaffney et al., 2006). Knowledge about the diversity, systematics, and phylogenetic relationships among the Bothremydina members has improved markedly over the past decades (Antunes and Broin, 1988;Lapparent de Broin and Werner, 1998) and, especially, during the last fifteen years (Zalmout et al., 2005;Gaffney et al., 2006;Joyce et al., 2016;P erez-García et al., 2017;P erez-García, 2017bP erez-García, , 2018. Interestingly, a specimen from the Cenomanian of Madagascar was recognized as a potential member of the genus Bothremys in the late 1980s (Antunes and Broin, 1988;, but it has remained unpublished until now, although allusions to it were subsequently compiled by Lapparent de Broin and Werner (1998) and Lapparent de Broin (2000), without providing additional information. ...
... . Bothremys is currently restricted to four species, distributed between the Santonian and the early Eocene: the Santonian Bothremys arabicus, the Campanian and Maastrichtian Bothremys cooki, the lower Palaeocene (Danian) Bothremys maghrebiana, and the lower Eocene (Ypresian) Bothremys kellyi (Gaffney et al., 2006). Knowledge about the diversity, systematics, and phylogenetic relationships among the Bothremydina members has improved markedly over the past decades (Antunes and Broin, 1988;Lapparent de Broin and Werner, 1998) and, especially, during the last fifteen years (Zalmout et al., 2005;Gaffney et al., 2006;Joyce et al., 2016;P erez-García et al., 2017;P erez-García, 2017bP erez-García, , 2018. Interestingly, a specimen from the Cenomanian of Madagascar was recognized as a potential member of the genus Bothremys in the late 1980s (Antunes and Broin, 1988;, but it has remained unpublished until now, although allusions to it were subsequently compiled by Lapparent de Broin and Werner (1998) and Lapparent de Broin (2000), without providing additional information. ...
... An African origin had been interpreted for Bothremydina Lapparent de Broin, 2000;Gaffney et al., 2006;P erez-García, 2018). The current position of Madagascar in relation to continental Africa was reached at the end of the Early Cretaceous, probably during the Aptian, as Madagascar had begun to drift from the continent at the end of the Jurassic (Seward et al., 2004). ...
The find of a partial shell of a pleurodiran turtle from the Cenomanian (basal Upper Cretaceous) of Madagascar was reported in the 1980s. It was then referred to as a potential member of the bothremydid Bothremys, but it has remained unpublished until now. Its attribution to Bothremydidae is confirmed here, since it is identified as a representative of Bothremydina, a clade known by several freshwater to littoral species from North America, southwestern Europe, northern Africa and the Middle East. The turtle from Madagascar, showing several exclusive characters within this lineage, is attributed to a new littoral form, Akoranemys madagasika gen. et sp. nov. It corresponds to one of the few Mesozoic turtle taxa defined in Madagascar, where only two pleurodires, belonging to other clades (the bothremydid Kurmademydini and the non-bothremydid Euraxemydidae), had been recognized at a specific level, both species being exclusive to the Maastrichtian record of that country. Therefore, Akoranemys madagasika corresponds to the oldest turtle defined for the fossil record of Madagascar, but also to one of the oldest known members of Bothremydina worldwide. The analyzed specimen is the only Mesozoic fossil turtle so far identified in the southwestern area of Madagascar, all other remains from that country coming from the northwestern region. Therefore, the presence of Bothremydina in Madagascar is confirmed by this unique member defined for the Southern Hemisphere, and the palaeobiogeographic distribution of this lineage is remarkably expanded.
... The palaeontological locality of Algora (Castilian Branch of the Iberian Ranges, Guadalajara Province, Castilla-La Mancha, central Spain; Fig. 1) has yielded the main concentration of Cenomanian vertebrate macroremains identified in south-western Europe (Torices et al., 2012;P erez-García et al., 2016a;P erez-García, 2018). ...
... Algorachelus peregrina has recently been recognized in middle Cenomanian levels of Portugal (P erez-García et al., 2017). In fact, the genus Algorachelus is currently not only identified in Europe but also in both the lowermiddle Cenomanian of Palestine, being represented by Algorachelus parva, and in the uppermost Cenomanian of Utah, where Algorachelus tibert is present (P erez-García, 2018). In addition to this coastal form, the remains of a generally pelagic clade have been identified at Algora (Bardet et al., 2018). ...
... Solemydidae is a clade of basal turtles exclusive to the Laurasiatic record; being known in North America and Europe Murelaga, 1996, 1999;Scheyer et al., 2015;Joyce, 2017;P erez-García, 2017b;P erez-García et al., 2020). This terrestrial clade is poorly represented in the uppermost Jurassic, but it is wellknown throughout the Cretaceous up to the Maastrichtian. ...
The palaeontological area of Algora (Guadalajara Province, central Spain) provides the largest concentration of vertebrate macroremains for the Cenomanian of south-western Europe. The available faunal list for Algora, based on the analysis of scarce remains collected in geological surveys carried out more than thirty years ago, was never updated. Therefore, and despite the great potential of this site to reveal novel information about the composition of the vertebrate fauna from the base of the Upper Cretaceous in the continent, the previous determination of many of the taxa recognized there is recognized here as inaccurate or erroneous (e.g., the identification of two actinopterygian fishes, a single crocodyliform, the helochelydrid turtle Helochelys danubina and carcharodontosaurid dinosaurs). Recent fieldwork campaigns have provided numerous remains, including those of clades poorly represented so far, as well as others hitherto unknown at this site. The new faunal list proposed here included the lepisosteoid Obaichthys africanus, the helochelydrid aff. Plastremys lata, the pleurodiran Algorachelus peregrina, an indeterminate elasmosaurid, a non-eusuchian neosuchian and a eusuchian crocodyliform, a likely abelisaurid theropod and a lithostrotian sauropod. The study of these taxa provides new information about the palaeobiogeography and temporal distributions of some lineages, and increases knowledge about the poorly-known transition between the Lower and the Upper Cretaceous faunas in Europe. This faunal replacement, in which several well-represented lineages in the uppermost Cretaceous were established, is recognized as strongly conditioned by climate changes that took place between the end of the Early Cretaceous and the beginning of the Late Cretaceous.
... The sauropod record of the European BarremianeAlbian (Lower Cretaceous) and CampanianeMaastrichtian (uppermost Cretaceous) are relatively abundant, with many occurrences. Particularly, during the BarremianeAlbian, sauropod faunas present an important diversity, being represented by titanosauriforms and rebbachisaurids (e.g., Canudo et al., 2008;Royo-Torres, 2009;Torcida Fern andez-Baldor, 2011, 2017Upchurch et al., 2011;Royo-Torres et al., 2012Le Loeuff et al., 2013;Dal Sasso et al., 2016;Mocho et al., 2017a). The uppermost Cretaceous record of Europe is noticeable by the presence of several titanosaurian occurrences (e.g., Ortega et al., 2015;, which resulted in the establishment of six valid taxa probably belonging to Lithostrotia (Le Loeuff, 1995;Sanz et al., 1999;García et al., 2010;Díez Díaz et al., 2016). ...
... The Iberian Cenomanian dinosaur record is extremely scarce. The recently found locality of Algora (Guadalajara, Central Spain) is located in the upper part of the Arenas de Utrillas Formation, in levels dated as uppermost middleelowermost upper Cenomanian (Torices et al., 2012;P erez-García et al., 2016P erez-García et al., , 2017. Several vertebrate clades have been reported there, including fishes, turtles, plesiosaurs, crocodyliforms and dinosaurs (Torices et al., 2012;P erez-García et al., 2013P erez-García et al., , 2016P erez-García, 2017P erez-García, , 2018. ...
... The recently found locality of Algora (Guadalajara, Central Spain) is located in the upper part of the Arenas de Utrillas Formation, in levels dated as uppermost middleelowermost upper Cenomanian (Torices et al., 2012;P erez-García et al., 2016P erez-García et al., , 2017. Several vertebrate clades have been reported there, including fishes, turtles, plesiosaurs, crocodyliforms and dinosaurs (Torices et al., 2012;P erez-García et al., 2013P erez-García et al., , 2016P erez-García, 2017P erez-García, , 2018. The only remains of dinosaurs from Algora so far studied corresponded to theropod teeth (Torices et al., 2012). ...
Algora is a recently discovered vertebrate fossil site located in the Cenomanian strata of the Arenas de Utrillas Formation (Guadalajara, Central Spain). This fossil site is rich in turtle remains, but other clades of reptiles are also identified, including plesiosaurs, crocodyliforms and dinosaurs. The only remains of dinosaurs from Algora so far studied corresponded to theropod teeth. However, several sauropod remains are here presented and analyzed, revealing the presence of several shared features with members of Titanosauriformes, some common found in derived members belonging to Lithostrotia clade. This sauropod fossil assemblage corresponds to the richest sauropod fossil accumulation found in the Cenomanian of Europe. In addition, one of the first studies of the pneumatic features in dorsal ribs using CT scan is also provided here. The performed cladistic analysis places the Algora sauropod within Lithostrotia, in a more derived position than Malawisaurus (supported, for example, by the presence of convex posterior articulation up to the posterior section of the tail), in a clade which also includes Rapetosaurus (Maastrichtian, Madagascar) and the Italian indeterminate titanosaur MSNM V7157 (late Aptian–early Albian). The Algora titanosaur and MSNM V7157 are recognized as closely related. This analysis shows the presence of two different lineages (Algora titanosaur + MSNM V7157 and Normanniasaurus, from the Albian of France) in the Early and middle Cretaceous of Europe, and at least one with a Gondwanan origin. The close relationship of the Algora titanosaur and MSNM V7157 suggests a pre-late Aptian faunal contact between the Adriatic Plate and Laurasia, in accordance with several previous studies, which proposed faunal exchanges between Laurasia and Gondwana through the Adriatic plate during the Early Cretaceous.
... Bothremydidae is the best represented group of turtles in the coastal and freshwater ecosystems of the Upper Cretaceous of southwestern Europe (Lapparent de Broin, 2001;Gaffney et al., 2006;Pérez-García, 2017b). The knowledge about the diversity and distribution of this lineage of Pleurodira in this region has improved markedly over the last twenty years (Tong et al., 1998;Murelaga, 1996, 1999;Laurent et al., 2002;Pérez-García et al., 2012;Pérez-García, 2016, 2017a. Bothremydidae is a group of Gondwanian origin, which reached Europe through several diachronic dispersion events (Pérez-García, 2017b). ...
... Bothremydidae is a group of Gondwanian origin, which reached Europe through several diachronic dispersion events (Pérez-García, 2017b). The oldest evidence of this lineage in this continent corresponds to the record of the Bothremydina (Bothremydini) Algorachelus peregrinus Pérez- García, 2017a, recognized in both the uppermost middle-lowermost upper Cenomanian of Algora (Guadalajara Province, Central Spain) and the middle Cenomanian of Nazaré (Central Portugal) (Pérez- García, 2017a;Pérez-García et al., 2017). The Campanian-Maastrichtian record of southwestern Europe includes a member of Taphosphyini (i.e., Taphrosphys ambiguus (Gaudry, 1890), represented by a single specimen from the Maastrichtian of the French locality of Mont-Aimé; Broin, 1977;Martin and Delfino 2010;Pérez-García, 2016), as well as several representatives of Bothremydini. ...
... Bothremydidae is a group of Gondwanian origin, which reached Europe through several diachronic dispersion events (Pérez-García, 2017b). The oldest evidence of this lineage in this continent corresponds to the record of the Bothremydina (Bothremydini) Algorachelus peregrinus Pérez- García, 2017a, recognized in both the uppermost middle-lowermost upper Cenomanian of Algora (Guadalajara Province, Central Spain) and the middle Cenomanian of Nazaré (Central Portugal) (Pérez- García, 2017a;Pérez-García et al., 2017). The Campanian-Maastrichtian record of southwestern Europe includes a member of Taphosphyini (i.e., Taphrosphys ambiguus (Gaudry, 1890), represented by a single specimen from the Maastrichtian of the French locality of Mont-Aimé; Broin, 1977;Martin and Delfino 2010;Pérez-García, 2016), as well as several representatives of Bothremydini. ...
Bothremydidae is the most abundant and diverse group of turtles in the upper Cretaceous fossil sites of southwestern Europe. Several species a priori recognized as exclusive of the Portuguese, Spanish and French records were defined. The most abundant and best preserved Spanish collection of pleurodiran turtles from the last Stages of the Upper Cretaceous comes from the fossil site of Lo Hueco (Cuenca Province, Central Spain). The bothremydid Iberoccitanemys convenarum, defined by a single specimen from the Maastrichtian of Haute-Garonne (Southern France), was subsequently recognized as a very abundant form in this Spanish site, corresponding to the only bothremydid so far identified as being part of the diversity of Bothremydidae of both countries. The presence of a second member of Bothremydidae was recognized in Lo Hueco, representing the only evidence of the synchronic and sympatric coexistence of two members of this lineage in a European site. However, very scarce information about this second form from Lo Hueco was available. Thus, its attribution to a new taxon or to a member of Foxemydina previously identified in the Spanish record, or in that of other European regions, could not be evaluated until now. New material from Lo Hueco, not attributable to Iberoccitanemys convenarum but to this second larger form, allows its generic and specific identification. Close paleobiogeographical relationships considering the fauna of pleurodiran turtles from Spain and France are recognized thanks to the findings performed in Lo Hueco: not only Iberoccitanemys convenarum is known in both countries, but also the French Foxemys mechinorum is identified in Central Spain.
... The type material of Algorachelus peregrinus was found during the first systematic excavation carried out in Algora, in which the objective was the evaluation of the potential interest of the fossiliferous levels (Pérez-García et al., 2013;Pérez-García, 2016). Therefore, that was a short field campaign but through which the interest of this fossil locality was confirmed, as well as the need for a future intervention. ...
... As a consequence, abundant material, especially of the turtle Algorachelus peregrinus, was found . A single relatively complete carapace from Algora was known, corresponding to the holotype of that taxon (see Pérez-García, 2016). In addition to a partial skull and several isolated appendicular elements, a fragment of carapace, partial carapaces and plastra, and several disarticulated plates had been described (Pérez-García, 2016). ...
... A single relatively complete carapace from Algora was known, corresponding to the holotype of that taxon (see Pérez-García, 2016). In addition to a partial skull and several isolated appendicular elements, a fragment of carapace, partial carapaces and plastra, and several disarticulated plates had been described (Pérez-García, 2016). The new material presented here corresponds to several complete or almost complete and very well-preserved shells, as well as to abundant articulated remains of both the carapace and the plastron. ...
Algorachelus peregrinus is the oldest representative of the crown group Pleurodira known in Laurasia. The type locality of this bothremydid is Algora, situated in central Spain, at levels deposited during the uppermost middle–lowermost upper Cenomanian. A new excavation was recently carried out in this town. As a result, abundant material of Algorachelus peregrinus has been found. Several complete shells, as well as numerous partial carapaces and plastra, are presented here. The abundance of remains allows the analysis of the general patterns by which some of the shells of this littoral form were partially or totally disarticulated. The analysis of these remains not only shows several pathologies but also improves the knowledge about the anatomy and intraspecific variability of Algorachelus peregrinus. This new information allows the revision of other Cenomanian forms of Bothremydidae, both from the Middle East and from North America. Thus, Algorachelus is identified in these regions, being represented in the early or middle Cenomanian of Palestine by the new combination Algorachelus parvus, and in the uppermost Cenomanian of Utah by the new combination Algorachelus tibert. Therefore, a relatively fast and widely distributed geographic dispersion event is recognized, corresponding to the oldest dispersal event so far identified for a lineage of Pleurodira from Gondwana to Laurasia.
... Thus, its Mesozoic record includes some Upper Jurassic and Lower and Upper Cretaceous basal forms (i.e. members of Pan-Pleurodira not attributable to the crown group Pleurodira), the platychelyids and the dortokids; as well as several Upper Cretaceous representatives of Bothremydidae (Pelomedusoides) (Lapparent de Broin and Murelaga, 1999;Gaffney et al., 2006;Cadena and Joyce, 2015;Pérez-García, 2016a). The bothremydids reached Europe at least from the middle Cenomanian, through several diachronic dispersal events from Africa (Pérez-García, 2016a;Pérez-García et al., 2017a). ...
... members of Pan-Pleurodira not attributable to the crown group Pleurodira), the platychelyids and the dortokids; as well as several Upper Cretaceous representatives of Bothremydidae (Pelomedusoides) (Lapparent de Broin and Murelaga, 1999;Gaffney et al., 2006;Cadena and Joyce, 2015;Pérez-García, 2016a). The bothremydids reached Europe at least from the middle Cenomanian, through several diachronic dispersal events from Africa (Pérez-García, 2016a;Pérez-García et al., 2017a). They were very abundant and diverse in the uppermost Cretaceous levels of several European countries (Portugal, Spain, France and Hungary) (Lapparent de Broin and Murelaga, 1999;Gaffney et al., 2006;Pérez-García et al., 2012;Rabi et al., 2012). ...
... The identification of sutured contacts between the pelvic and the shell, both with the carapace (generating the iliac scar) and the plastron (forming the ischiatic and pubic scars), allows the attribution of NHMUK R12773 to Pan-Pleurodira (Pérez-García, 2016a). The presence of a medial contact of the gulars, located posteriorly to the intergular scute, shows that this specimen belong to the Erymnochelys group (see Broin, 1988;Lapparent de Broin, 2000a, 2000bLapparent de Broin in Merle, 2008Pérez-García and Lapparent de Broin, 2015;Pérez-García et al., 2017b). ...
A turtle shell from the lower Eocene of the Bracklesham Bay (Sussex, England), preserving the partial carapace and the almost complete plastron, is studied here. It is recognized as a member of Pleurodira, being attributed to the coastal podocnemidid Eocenochelus. This systematic identification confirms the presence of Podocnemididae in the British record, corresponding to the first evidence of the presence of this genus of the Erymnochelys group (Erymnochelyinae) outside continental Europe. The finding shows that this lineage of African origin not only reached southern France during the early Eocene, but its dispersion towards higher latitudes also occurred at that time, across epicontinental areas.
... The specimen studied here (i.e., the almost complete and articulated shell NHMUK R37356) displays a combination of shell characters that allows its identification as a pleurodiran turtle, attributable to the lineage of Bothremydidae: low and subrounded shell; long first neural and first pair of costals, with this pair of costals being about twice longer than the second pair; relatively short neural series composed of fewer than eight plates, allowing the medial contact of the posterior costals; axillary buttresses showing a long contact with the third pair of peripherals, and inguinal buttresses reaching the fifth costals; relatively small mesoplastra, laterally located; and the absence of a cervical scute [1,7,[22][23][24][25]. Therefore, its attribution to other ornate-shelled pleurodiran lineages recognized in the African Cretaceous record (e.g., Araripemydidae) is excluded. ...
... However, NHMUK R37356 is clearly recognized as a representative of the clade Bothremydodda based on the presence of a wide anterior plastral lobe. In fact, as happens with representatives of this lineage, this lobe is interpreted as relatively short, with its anterior margin probably not exceeding that of the carapace [1,24,26]. Gaffney et al. (2006) [1] recognized two lineages for Bothremydodda, i.e., Bothremydini and Taphrosphyini. For these authors, this second lineage integrated members of Nigeremydina (exclusively including two African Upper Cretaceous taxa: Nigeremys gigantea, from the Maastrichtian of Niger, and Arenila krebsi Lapparent de Broin and Werner, 1998 [27], from the Maastrichtian of Egypt) and those of the much more diverse Taphrosphyina. ...
A new pleurodiran turtle is described here. It is identified as attributable to Bothremydidae. The new taxon comes from an upper Maastrichtian (Upper Cretaceous) outcrop located in Southwestern Niger (in the Indamane Mount area, belonging to the Abalak Department of the Tahoua Region). Abalakemys chapmanae gen. et sp. nov. is identified by an almost complete large shell of about 65 cm in length. The new bothremydid turtle is recognized as a member of Bothremydodda, showing several autapomorphies (an exclusive ornamental pattern on the plate’s outer surface, covered by small depressions; small fourth pleural scutes, only anteromedially reaching the sixth pair of costal plates; and noticeably wedged posterior plastral lobe toward the posterior region), as well as a unique combination of characters for this clade. This turtle could belong to Nigeremydini, a poorly understood Maastrichtian to Paleocene lineage of Bothremydodda, which integrates large coastal taxa that inhabited the African Trans-Saharan seaway, and for which shell information is currently extremely limited.
... Este yacimiento es de especial interés por los restos de vertebrados del Cenomaniense medio-superior entre los que se incluyen peces, tortugas, cocodriliformes, dinosaurios y otros reptiles como plesiosaurios Torices et al., 2010Torices et al., , 2012Bardet et al., 2013;Pérez-García et al., 2013;Narváez et al., 2014;Pérez-García et al., 2016, 2017, 2020, siendo el yacimiento paleontológico con mayor concentración de vertebrados del Cenomaniense del Sur de Europa (Pérez- García et al., 2020). Sin embargo, también destaca la presencia de abundantes restos de plantas fósiles, y de algunos moldes de invertebrados, principalmente bivalvos (Berrocal- Casero et al., 2015). ...
... En Tamajón, se han descrito casi 30 especies (Meléndez-Hevia, 1984;Barroso-Barcenilla et al., 2009, 2017. Entre las especies representadas, en la parte inferior de la formación destacan Eucalycoceras rowei, Neolobites vibrayeanus y Metoicoceras geslinianum (Figura 39A). ...
... The presence of a wide but relatively short anterior plastral lobe allows its attribution to Bothremydodda. It shares with the only representative of this clade so far found in the Cenomanian record of Europe, Algorachelus, the relative small size, less than 25 cm; the low but wide shell (being almost as wide as long); and the absence of a deep nuchal notch, showing a wide anterior carapace margin, subperpendicular to the axial plane (de Lapparent de Broin and Murelaga 1999;Gaffney et al. 2006;Pérez-García 2017b, 2018. In fact, this combination of characters is recognized as exclusive to the representatives of the Cenomanian genus Algorachelus (Pérez-García 2017b, 2018. ...
... It shares with the only representative of this clade so far found in the Cenomanian record of Europe, Algorachelus, the relative small size, less than 25 cm; the low but wide shell (being almost as wide as long); and the absence of a deep nuchal notch, showing a wide anterior carapace margin, subperpendicular to the axial plane (de Lapparent de Broin and Murelaga 1999;Gaffney et al. 2006;Pérez-García 2017b, 2018. In fact, this combination of characters is recognized as exclusive to the representatives of the Cenomanian genus Algorachelus (Pérez-García 2017b, 2018. ...
The internal cast of a turtle shell, found near the town of Cabrejas del Pinar (Soria Province, Castile and Leon Autonomous Community, Spain), is presented here. It is the first fossil vertebrate recognized in the vicinity of that town. This specimen was found in a middle Cretaceous bed (Cenomanian), deposited in a coastal marine environment. It is recognized as attributable to a member of the crown group Pleurodira. No representative of this clade had so far been found in pre-Campanian strata in the Castile and Leon Autonomous Community. In fact, the pre-Campanian record of the crown Pleurodira is very limited in Laurasia. The hitherto known record of pre-Campanian turtles from Castile and Leon consisted of basal forms (members of the terrestrial clade Helochelydridae and of the freshwater Pleurosternidae) and of freshwater representatives of Eucryptodira, all of them found in layers older than that where the new turtle remain was found. The availability of characters in the analyzed specimen allows it to be recognized as compatible with the littoral bothremydid turtle Algorachelus.
... However, the British record of Pleurodira is very limited, being restricted to only a few relatively poorly known and poorly represented forms from the lower Eocene (Gaffney et al., 2006;Pérez-García and Chapman, 2017). Several events of dispersion of this group of Gondwanan origin to continents that were part of Laurasia are known, and more specifically to Europe, both during the Mesozoic and the Cenozoic (Pérez-García, 2016a, 2017. Two successful lineages of Pleurodira are identified in the Eocene levels of Europe: Bothremydidae and Podocnemididae (Lapparent de Broin, 2001). ...
... Palemys bowerbankii is obtained as a member of Bothremydini Foxemydina, a clade composed of several Santonian to lower Eocene European forms. The Colombian Paleocene Puentemys mushaisaensis Cadena et al., 2012 is also obtained as a member of this clade (as in some previous phylogenetic hypotheses, such as those of Cadena et al., 2012, andPérez-García, 2016a;but not in Pérez-García, 2016b). In addition to several cranial characters, Foxemydina is defined here by the overlap of the anterior region of the pectoral scutes on the epiplastra (character 166, state 1; not shared with some specimens of Puentemys mushaisaensis), and by the presence of the first vertebral scute wider than the second (character 178, state 2; not shared with some specimens of Foxemys mechinorum Tong et al., 1998 and with Palemys bowerbankii). ...
... Stromer (1934b) noted similarities to several cryptodiran and pleurodiran turtles but did not conclude to which higher taxon the new genus and species belonged. Subsequent studies generally classified Apertotemporalis as a bothremydid pleurodiran (de Lapparent de Broin, 2000;Pérez-García, 2017;Zalmout et al., 2005). ...
Egypt has yielded some of the richest and most spectacular records of Mesozoic terrestrial vertebrates from Africa. Certainly, the best-known and most diverse of these are the vertebrate assemblages of the Upper Cretaceous Bahariya Formation (Cenomanian), which includes numerous different taxa of fishes, abundant remains of turtles and crocodyliforms, as well as several different theropod and sauropod dinosaurs. Originally discovered early in the twentieth century by famous German palaeontologist Ernst Stromer von Reichenbach and fossil collector Richard Markgraf, most of the material has subsequently been destroyed during the Second World War. Aside from the high diversity, the Bahariya Formation also yielded some of the most bizarre and iconic dinosaurs such as the giant theropods Spinosaurus and Carcharodontosaurus or the enormous sauropod Paralititan. Although the Bahariya Oasis has yielded by far the most diverse and extensive remains of Mesozoic terrestrial vertebrates from Egypt, other localities from the Turonian, Campanian and Maastrichtian offer additional important—albeit much less complete—insights into the composition and evolution of African Late Cretaceous terrestrial ecosystems. Some of these assemblages, especially the latest Cretaceous Quseir Formation, have just begun to reveal the richness and diversity of their vertebrate fauna, often with spectacular results, and certainly have the potential to yield further significant insights into the evolution of the Cretaceous life on land. In this chapter, we provide a summary of the terrestrial Mesozoic vertebrate record of Egypt and thus an overview of these remarkable dinosaur faunas.KeywordsEgyptDinosauriaCrocodyliformesTestudinataBahariya FormationQuseir Formation
... Panpleurodiran turtles date to the Late Jurassic period and continue to be part of the current biodiversity [1][2][3][4][5]. Although they are currently restricted to the southern hemisphere, numerous pleurodiran lineages are identified in the fossil record of several Laurasian continents, showing great success in both abundance and diversity (e.g., [6][7][8][9]). The greatest diversity of the Pleurodira is demonstrated by the fossil record of both South America and Africa (e.g., [10][11][12][13]). ...
The Pleurodira represent one of the two clades that compose the crown Testudines, and their temporal range is Late Jurassic–present. However, knowledge about the neuroanatomy of extinct pleurodires is still very limited. In this context, scarce neuroanatomical information about the Cretaceous clade Euraxemydidae is currently available, limited to some characters of the Moroccan Cenomanian Dirqadim schaefferi. In the present work, we perform the detailed neuroanatomical study of its sister taxon, the Brazilian Albian Euraxemys essweini, based on the analysis of the skull of its holotype and only known individual of the species. The detailed virtual three-dimensional reconstruction of all its cranial bones is performed, also improving the information about its osseous anatomy. The different neuroanatomical cavities (i.e., cranial, nasal, and labyrinthic ones) and canals (i.e., nervous and circulatory ones) are compared with those identified thus far for other extinct and extant members of the Pleurodira in order to characterize the neuroanatomy of the extinct clade Euraxemydidae in detail.
... This is the most frequent condition in extant and fossil podocnemidids, with some exceptions observed in specimens of Peltocephalus dumerilianus and Podocnemis erythrocephala where the most posterolateral corners of the pectorals covered the mesoplastra. The abdominal scutes were the longest of the plastron, slightly longer medially than the pectorals and femorals, similar as in all other extant and fossil podocnemidids, differing from the most variable condition of medial length exhibited by these three pairs of scutes of bothremydids (Cadena et al. 2012;de Araújo-Carvalho et al. 2016;Pérez-García 2016;Pérez-García et al. 2020). The anal scutes of P. tatacoensis n. sp. ...
The estimate divergence time for extant taxa based on molecules usually exceed the age of their oldest fossil evidence; a situation that turtles do not scape. An extant genus with this situation, and thus having a controversial oldest record is Podocnemis Wagler, 1830. Here we present a new fossil turtle that constitutes a new species for this genus and represents its oldest so far known record, from the Miocene (Serraval- lian) of La Tatacoa Desert, Colombia. The new taxon named Podocnemis tatacoensis n. sp. shares with all extant members of Podocnemis a nuchal bone wider than long; lateral musk foramina at the hyoplastron- peripherals (except P. sextuberculata Cornalia, 1849), pectoral scales do not contact mesoplastra, but do contact entoplastron and epiplastra. We explored the phylogenetic position of P. tatacoensis n. sp. find- ing support for its inclusion as part of Podocnemis clade, particularly in a clade composed by the extant P. unifilis Troschel, 1848, suggesting a potential closer relationship of the new fossil taxon with this taxon.
... The latter taxon from Gadoufaoua is a Pelomedusoides showing many primitive features and few derived features, such as a marked fine polygonal decoration and the low shell shape with rounded peripheral border, shared with the Bothremydidae. During the Cenomanian, the continental bothremydids became littoral turtles, and widely spread along the coasts of the western Tethys-Atlantic, between Africa, Middle East and Europe, being notably known during the Cenomanian of Palestine and Portugal (Haas 1978a, b;Pérez-García 2016, 2018aPérez-García et al. 2017a) and up to North America (Joyce et al. 2016 (Carter 1852, Williams 1953Jain 1977Jain , 1986Gaffney et al. 2001bGaffney et al. , 2003Gaffney et al. , 2006Lapparent de Broin & Guntupalli 2020) and in Madagascar (Gaffney et al. 2006;Gaffney & Krause 2011;Gaffney et al. 2009). Another unnamed taxon is known from the Cenomanian of Madagascar (Lapparent de Broin & Werner 1998;Lapparent de Broin 2000;Lapparent de Broin & Guntupalli 2020). ...
We report the discovery of remains of a large chelonian from the base of the early Paleocene Khadro Formation exposed in the Ranikot Fort area (Ranikot Group, Sindh Province, Southern Pakistan). This formation already yielded the snake Gigantophis Andrews, 1901, studied by our friend Jean-Claude Rage. The chelonian specimens consist of a large carapace and a shell fragment of Bothremydidae, a family of Gondwanan origin. A new genus and species, Sindhochelys ragei n. gen., n. sp. is identified from the first specimen and named in honor of Jean-Claude Rage. It is the first report of a Bothremydidae in Southern Pakistan. Its affinities with Cretaceous and Paleocene representatives of the family are discussed. The association of characters such as the shape of the shell, anterior plastral scute pattern and strongly marked decoration characterize the taxon and, despite some similarities, allows excluding close phylogenetic affinities with Taphrosphyini and Carteremys group; other well-documented bothremydids are also excluded. The shell fragment, also strongly decorated, is left undetermined. The discovery of two new littoral bothremydid specimens in the early Paleocene of Pakistan fills a geographic and stratigraphic gap in our knowledge of the family, which is known since the continental early Cretaceous of Africa, diversifying in the world up to the Miocene deposits of the Neotethys. A particular diversification during the Maastrichtian-Paleocene is recognized along the neotethyan coasts, and occasional dispersals across this ocean were possible. Sindhochelys ragei n. gen., n. sp. may have colonized the Indian subcontinent by this time, or may represent an older diversification before the Gondwana breakup.
... The latter taxon from Gadoufaoua is a Pelomedusoides showing many primitive features and few derived features, such as a marked fine polygonal decoration and the low shell shape with rounded peripheral border, shared with the Bothremydidae. During the Cenomanian, the continental bothremydids became littoral turtles, and widely spread along the coasts of the western Tethys-Atlantic, between Africa, Middle East and Europe, being notably known during the Cenomanian of Palestine and Portugal (Haas 1978a, b;Pérez-García 2016, 2018aPérez-García et al. 2017a) and up to North America (Joyce et al. 2016 (Carter 1852, Williams 1953Jain 1977Jain , 1986Gaffney et al. 2001bGaffney et al. , 2003Gaffney et al. , 2006Lapparent de Broin & Guntupalli 2020) and in Madagascar (Gaffney et al. 2006;Gaffney & Krause 2011;Gaffney et al. 2009). Another unnamed taxon is known from the Cenomanian of Madagascar (Lapparent de Broin & Werner 1998;Lapparent de Broin 2000;Lapparent de Broin & Guntupalli 2020). ...
We report the discovery of remains of a large chelonian from the base of the early Paleocene Khadro Formation exposed in the Ranikot Fort area (Ranikot Group, Sindh Province, Southern Pakistan). This formation already yielded the snake Gigantophis Andrews, 1901, studied by our friend Jean-Claude Rage. The chelonian specimens consist of a large carapace and a shell fragment of Bothremydidae, a family of Gondwanan origin. A new genus and species, Sindhochelys ragei n. gen., n. sp. is identified from the first specimen and named in honor of Jean-Claude Rage. It is the first report of a Bothremydidae in Southern Pakistan. Its affinities with Cretaceous and Paleocene representatives of the family are discussed. The association of characters such as the shape of the shell, anterior plastral scute pattern and strongly marked decoration characterize the taxon and, despite some similarities, allows excluding close phylogenetic affinities with Taphrosphyini and Carteremys group; other welldocumented
bothremydids are also excluded. The shell fragment, also strongly decorated, is left
undetermined. The discovery of two new littoral bothremydid specimens in the early Paleocene of Pakistan fills a geographic and stratigraphic gap in our knowledge of the family, which is known since the continental early Cretaceous of Africa, diversifying in the world up to the Miocene deposits of the Neotethys. A particular diversification during the Maastrichtian-Paleocene is recognized along the neotethyan coasts, and occasional dispersals across this ocean were possible. Sindhochelys ragei n. gen., n. sp. may have colonized the Indian subcontinent by this time, or may represent an older diversification before the Gondwana breakup.
... salmanticensis (Jiménez-Fuentes, 1968, 2007. In no species of Bothremydidae in which the sexual dimorphism has been recognized the sex of each of the morphotypes has been specified (e.g., Algorachelus peregrina Pérez- García, 2016;Guerrero & Pérez-García, 2019). Thus, as qualitatively and quantitatively (see Results) demonstrated for some pleurodiran clades that are part of the current biodiversity, the magnitude and direction of sexual selection for this trait vary at the genus level. ...
The present study characterizes the morphological variability related to the sexual dimorphism in the shells of the Spanish Upper Cretaceous turtle Dortoka vasconica. This study is based on the material from its type locality: Laño, Burgos. Two morphotypes were identified there based on the posterior plastral area as well as two for the anterior plastral lobe. However, a correlation with the previously indicated morphotypes could not be established due to the disarticulation of the specimens and the limited information available on the sexual dimorphism of Pleurodira. The morphological variability previously identified for Dortoka vasconica is analysed here through a quantitative approach to evaluate the role that sexual dimorphism plays in the plastron. Comparative material of the main extinct and extant groups of pleurodires is included in this study. The results evidenced a noticeable sexual dimorphism in the anal notch of Dortoka vasconica. Likewise, the comparison of species belonging to several pleurodiran clades shows a wide range of variability in the direction and magnitude of the sexual dimorphism. Thus, a single evolutionary trend cannot be recognized, so that previous assumptions about which morphotype corresponds to each sexual dimorph in some extinct taxa and especially lineages (including basal pan-pleurodires) cannot be confirmed.
... Over the course of the last 25 years, however, an astounding diversity of fossil forms has been documented from Cretaceous to Palaeocene strata (e.g. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]). These fossils not only expand the range of pelomedusoids to Arabia, the Caribbean, Europe, India and North America but also document an incredible array of diversity and disparity within the group. ...
The Maevarano Formation in northwestern Madagascar has yielded a series of exceptional fossils over the course of the last three decades that provide important insights into the evolution of insular ecosystems during the latest Cretaceous (Maastrichtian). We here describe a new genus and species of pelomedusoid turtle from this formation, Sahonachelys mailakavava, based on a nearly complete skeleton. A phylogenetic analysis suggests close affinities of Sahonachelys mailakavava with the coeval Madagascan Sokatra antitra. These two taxa are the only known representatives of the newly recognized clade Sahonachelyidae, which is sister to the speciose clade formed by Bothremydidae and Podocnemidoidae. A close relationship with coeval Indian turtles of the clade Kurmademydini is notably absent. A functional assessment suggests that Sahonachelys mailakavava was a specialized suction feeder that preyed upon small-bodied invertebrates and vertebrates. This is a unique feeding strategy among crown pelomedusoids that is convergent upon that documented in numerous other clades of turtles and that highlights the distinct evolutionary pathways taken by Madagascan vertebrates.
... The anatomical study of these remains is presented here, so that the precise systematic attribution of the form represented in Algora is discussed, taking into account the European record of Helochelydridae. (Pérez-García, 2017b;Pérez-García et al., 2017). With the exception of these findings, no other remains attributable to this group of pleurodiran turtles had been documented, so far, at pre-Campanian levels of southwestern Europe. ...
... More recently Pérez-García (2017 has attempted to resurrect Taquetochelys decorata and reduce Laganemys tenerensis as a junior synonym by arguing that the differences cited between their hypoplastra fall within an acceptable range of individual variation. Pérez-García stated that "the anterior margin of the hypoplastron" was broken away, rendering ineffective any shape differences based on this bone. ...
The geological and paleoenvironmental setting and the vertebrate taxonomy of the fossiliferous, Cenomanian-age deltaic sediments in eastern Morocco, generally referred to as the “Kem Kem beds”, are reviewed. These strata are recognized here as the Kem Kem Group, which is composed of the lower Gara Sbaa and upper Douira formations. Both formations have yielded a similar fossil vertebrate assemblage of predominantly isolated elements pertaining to cartilaginous and bony fishes, turtles, crocodyliforms, pterosaurs, and dinosaurs, as well as invertebrate, plant, and trace fossils. These fossils, now in collections around the world, are reviewed and tabulated. The Kem Kem vertebrate fauna is biased toward largebodied carnivores including at least four large-bodied non-avian theropods (an abelisaurid, Spinosaurus, Carcharodontosaurus, and Deltadromeus), several large-bodied pterosaurs, and several large crocodyliforms.
No comparable modern terrestrial ecosystem exists with similar bias toward large-bodied carnivores. The Kem Kem vertebrate assemblage, currently the best documented association just prior to the onset of the Cenomanian-Turonian marine transgression, captures the taxonomic diversity of a widespread northern African fauna better than any other contemporary assemblage from elsewhere in Africa.
Keywords
Africa, Cretaceous, dinosaur, Gara Sbaa Formation, Douira Formation, paleoenvironment, vertebrate
... The first dispersal events of Pleurodira to Laurasia, performed by members of Bothremydidae, are identified from the Cenomanian (Pérez-García 2017b, 2018a. This dispersal to Europe was very successful, the pleurodires Bothremydini becoming the most abundant and diverse turtles in the freshwater and transitional environments of the uppermost Cretaceous of this continent (Pérez-García 2017a). ...
Pleurodiran turtles are relatively abundant in the Eocene record of Europe, being mostly represented by Podocnemididae. Two genera have been identified. The most abundant and diverse is the well-known freshwater Neochelys. The other is Eocenochelus. The record of this poorly-known genus is very scarce. It is the only representative of the Upper Cretaceous to extant Erymnochelyini (i.e., a new tribe proposed here for the ‘Erymnochelys group of turtles’) interpreted as a littoral form, and the only one known outside Africa. The finding of the only complete shell of Eocenochelus hitherto identified is presented here. It comes from the Castejón de Sobrarbe-41 site, in the middle Eocene (Lutetian) of the Sobrarbe Formation of the Ainsa Basin (Huesca, Spain). The sedimentary environment of the site is compatible with its attribution to a littoral form. It is attributed to the type species of the genus, Eocenochelus eremberti, so far exclusively known by two partial shells from the middle Eocene of the Franco-Belgian Basin. Therefore, the paleobiogeographic distribution of this species is markedly increased, from the southern area of the North Sea to the Bay of Biscay. This finding provides new anatomical data on the species Eocenochelus eremberti and on its poorly known genus.
urn:lsid:zoobank.org:act:5FF64A63-3187-4752-A62E-016308877022
... Lamentablemente, el registro de vertebrados del Cenomaniense de Europa es muy limitado y, hasta ahora, no existían yacimientos con registro abundante de macrovertebrados continentales. Sin embargo, los trabajos realizados en los últimos años en la localidad española de Algora (Guadalajara, Castilla-La Mancha), han puesto de manifiesto la presencia de un yacimiento del Cenomaniense medio-superior en el que se identifica una fauna diversa, con varios linajes que presentan evidentes relaciones gondwánicas (Torices et al., 2012;Pérez-García et al., 2013, 2016Pérez-García, 2018). Allí se identifican varios grupos de vertebrados que serán muy abundantes al final del Cretácico. ...
... As mentioned above, the discovery of Bicuspidon in the Cenomanian of Morocco offers clues to the presence of polyglyphanodontine taxa (Bicuspidon and Distortodon) in the Santonian of Hungary and the Maastrichtian of Romania (Folie and Codrea 2005;Makádi 2006Makádi , 2013a. Like European Late Cretaceous occurrences of neobatrachian anurans (Szentesi and Venczel 2010), bothremydid turtles (Rabi et al. 2012;Pérez-García 2017), madtsoiid snakes (Vasile et al. 2013), and notosuchian crocodyliforms (Rabi and Sebők 2015), the presence of Bicuspidon (as well as Distortodon) Rabi and Sebők (2015). Thus, Beringia and Asia may not have played a role in the dispersal of Bicuspidon to Europe. ...
Borioteiioidea are an enigmatic group of Cretaceous lizards widely distributed in northern continents (Laurasia). Here, we describe the first borioteiioid lizard from Gondwana, represented by a new species of the polyglyphanodontine genus Bicuspidon, B. hogreli sp. nov., from the Cenomanian Kem Kem beds of Morocco. The discovery of Bicuspidon hogreli sp. nov., which is one of the oldest known member of Polyglyphanodontini, challenges previous assumptions on the center of origin and dispersal of the group. In addition, the known distribution of Bicuspidon (Cenomanian of Utah and Morocco, and Santonian–Maastrichtian of eastern Europe) suggests a complex palaeobiogeographical history for the genus. The existence of a terrestrial dispersal route persisting during the whole Early Cretaceous between North America and Africa is hypothesized to explain some similarities observed between the Cenomanian squamate assemblages of these two continents. Alternatively, dispersal between the two landmasses may have occurred by transatlantic rafting. During the Cenomanian–Santonian interval, Bicuspidon colonized the European archipelago probably from North Africa, like many “Eurogondwanan” taxa.
... The presence of Paleogene Bothremydidae is also attested by three European elements, two of which are from the middle Eocene (Lutetian) (Spain in Catalonia at Montjuïc, and Italy at Avesa), such as the Taradell specimen, and between the ages of Ypresian of Saint-Papoul and London Clay and the late Eocene (Priabonian) of Osona County. The third element is from the Oligocene of France (at Montoulieu) (Broin, 1977;Lapparent de Broin et al., 2014b;Lapparent de Broin and Werner, 1998;Pérez-García, 2016a, b) (Supplement, Sect. S3). ...
Eochelone voltregana n. sp. is a new marine cryptodiran cheloniid found at the Priabonian levels (latest Eocene) of the Vespella marls member of the Vic–Manlleu marls formation. It is the second cheloniid from Santa Cecília de Voltregà (Osona County, Spain), the first one being Osonachelus decorata from the same formation. Shell parameters indicate that the new species belongs to a branch of sea turtles including the Eocene Anglo–Franco–Belgian forms Argillochelys, Puppigerus and Eochelone (the shell of the latter was studied here for the first time) as well as Glarichelys from the Oligocene of Switzerland, all of them predating the worldwide living Miocene genera. The description of two other more littoral–continental Eocene species is given: Trionyx sp., from an older layer of the same formation; and the podocnemidid erymnochelyine, Cordichelys from a more basal layer of a middle Eocene (Lutetian) formation. The last one is identified as the only evidence of the Shweboemys subgroup in the European record, being distinct from the other known Osona County pleurodire Eocenochelus farresi, which is a member of the Erymnochelys group (same subfamily), from the younger Priabonian Sant Martí Xic layer. Thus, an update on the marine turtle fauna of the eastern Ebro Basin that variably opened in the east during Eocene times is provided. The turtles of Osona County belong to two suborders and five genera with three new species and extend the known distribution of their families (LSID urn:lsid:zoobank.org:act:48CE8676-7B82-4EF2-8165-27BEE90129F2).
... Two lineages of the crown Pleurodira have been recognized in the European fossil record, both coming from Africa. One of them is Bothremydidae, identified in Europe from the Cenomanian ( Pérez-García, 2016a). The greatest diversity of this lineage in Europe was achieved during the uppermost Cretaceous ( Tong et al., 1998;de Lapparent de Broin, 2001;Gaffney et al., 2006;Pérez-García et al., 2012). ...
An almost complete plastron, as well as several peripherals and a costal
plate of a turtle from the middle Eocene of Saint-Gilles, is presented here.
Although this turtle specimen was donated to the Institut royal des Sciences
naturelles de Belgique (Brussels, Belgium) more than a century ago, it
remained undescribed. Its study allows us to recognize the second
pleurodiran in the Belgian fossil record, where, until now, the Eocene
Neochelys was the only one known. The Belgian material of Neochelys is known in lower Eocene
(early Ypresian) levels, but the new pleurodiran specimen comes from the
middle Eocene (early Lutetian). It is the first partial articulate shell of
a pleurodiran turtle recognized in Belgium, and the only member of this
clade recognized in this country at specific level. The new specimen is a
representative of the so-called Erymnochelys group, this lineage being known in Africa from
the Upper Cretaceous to the present but in Europe only during the Eocene.
It represents the first specimen of Eocenochelus eremberti identified outside its type locality,
the French region of Saint-Germain-en-Laye (Yvelines, Île-de-France),
where only one specimen was found. The plastron of the Belgian individual
corresponds to the most complete for this species. Its analysis
allows us not only to broaden the range of paleobiogeographical distribution of
Eocenochelus eremberti but also to improve the knowledge about the anatomy and variability of
this taxon.
... The other representative of the stem group of Pleurodira in Laurasia is the Tithonian Platychelys oberndorferi Wagner 1853, a member of Platychelyidae defined in Germany, this genus having subsequently been identified in the Kimmeridgian of Switzerland (Rütimeyer 1867(Rütimeyer , 1873. During the Late Cretaceous, Dortokidae coexisted in European freshwater environments with some members of Pleurodira, corresponding to Bothremydidae, a lineage of African origin that reached Europe in the early Late Cretaceous, and show its maximum European diversity in the uppermost Cretaceous record (Gaffney et al. 2006;Pérez-García et al. 2012a;Pérez-García 2016a), surviving in this continent until the Eocene (Pérez-García 2016b). The known diversity of Dortokidae is limited to three representatives (Fig. 1). ...
Dortokidae is a poorly understood group of pan-pleurodires, exclusive to the European record. Dortokidae is one of the few defined clades of the stem group of Pleurodira, grouping all the forms of this stem described in the post-Jurassic record of Laurasia. Despite this clade has a relatively wide temporal distribution, only three valid forms of Dortokidae are currently known: one from the late Barremian (Early Cretaceous) of Morella (Spain), Eodortoka morellana; another from the uppermost Cretaceous of Spain and probably southern France, Dortoka vasconica; and the last one from the Paleogene of Romania, Ronella botanica. The oldest of these taxa is synchronous with the findings of Dortokidae indet. from the Spanish fossil locality of Vallipón, Vallipón and Morella being the only two localities where Lower Cretaceous material of this clade was so far known. Dortokidae is recognized in this paper for the first time in El Castellar Formation, by a partial xiphiplastron. This finding comes from the El Castellar locality (Teruel, Spain). The plate from El Castellar is compared with the xiphiplastra of all so far valid representatives of Dortokidae, and with the indeterminate form from Vallipón. A phylogenetic hypothesis on the members of this clade is proposed. The specimen studied here is identified as the oldest known evidence of Dortokidae, being recognized as Dortokidae indet. This new remain of a dortokid expands the known temporal range of distribution for this clade, being recognized from the uppermost Hauterivian-basal Barremian levels.
... Buscalioni et al. (2001) assigned a fragment of skull recovered in Els Nerets-Vilamitjana (Tremp, Lleida) to the Romanian species Allodaposuchus precedens. However, recent phylogenetic hypotheses consider that the species Allodaposuchus precedens is restricted to Eastern Europe (Delfino et al. 2008;Narváez et al. 2015;2016), and a reevaluation of this cranial material from Vilamitjana does not allow to assign it beyond of Allodaposuchidae indet. (Narváez et al. 2017). ...
Purpose
The development of the studies on Mesozoic reptiles of the Spanish record occurred much later than in several European countries such as United Kingdom, France or Germany. Thus, very scarce and punctual findings were performed in the second half of the 19th century, followed by the work of José Royo y Gómez, which was stopped by the Spanish Civil War. The professional surveys and studies carried out in the 1950s in the Upper Cretaceous levels of the Tremp Basin (Lleida, Catalonia, Spain) can be considered as the origins of the development of this discipline in Spain. The works in the Tremp Basin were performed through the collaboration of national and foreign researchers. The Spanish palaeontologist Emiliano Aguirre and the French Albert Félix de Lapparent published some preliminary notes on the vertebrate fauna identified there. However, no detailed systematic study of these historical remains was ever done.
Methods
The unpublished historical remains from the Tremp Basin collected by Aguirre and Lapparent, and preserved in the Museo Nacional de Ciencias Naturales (Madrid) collections, are studied here.
Results
The analysis of unpublished historical documentation housed in the archive of that institution allows us to improve the knowledge about the history of these findings, as well as to recognize the precise sites from which each of these fossils come.
Conclusion
The systematic study of these specimens, corresponding to turtles, crocodiles and dinosaurs, is performed here. They are attributed to Bothremydidae indet., cf. Pan-Cryptodira, cf. Allodaposuchidae, Titanosauria indet., Nodosauridae indet. and Ornithopoda indet.
... In fact, this lineage is relatively abundant and diverse in the European Eocene record. Neochelys Bergounioux, 1954 is a genus restricted to Europe, being represented by several continental species identified in lower, middle and upper Eocene levels from several countries (Pérez-García andLapparent de Broin, 2013, 2015;Cadena, 2015a) (Figure 1). Another form was defined in the European Eocene record: 'aff. ...
The Erymnochelys group is a lineage of Erymnochelyinae, pleurodiran turtles that originated in Africa, with a fossil record extending from the Late Cretaceous. It is currently represented by a single species, the Malagasy Erymnochelys madagascariensis. Information on most of its fossil representatives is sparse. In fact, the oldest unambiguous generic determinations heretofore established within the group are those of Turkanemys and Kenyemys, both from the latest Miocene-Pliocene of Kenya. The description and illustration of the French middle Eocene species ‘aff. Erymnochelys’ eremberti is completed here, and a diagnosis for this species is proposed for the first time. It is attributed to a new genus, Eocenochelus, the first genus of the Erymnochelys group defined outside of Africa. Eocenochelus is also recognized in the European lower and upper Eocene record by two new species, Eocenochelus lacombianus and Eocenochelus farresi, respectively. Therefore, Eocenochelus is a taxon with a wide distribution in Europe during the Eocene and is relatively diverse. This is also the case with the continental Neochelys, the only other podocnemidid genus so far recognized in the European Paleogene record. Exclusively identified in coastal deposits, Eocenochelus is the only known form of the Erymnochelys group found in marginal marine sediments. Its anatomical adaptations probably facilitated the spread from Africa to Europe.
The Cenomanian (lowermost Upper Cretaceous) faunal assemblages are of high interest in understanding the turnovers that took place between the Early and the Late Cretaceous, resulting in significant differences. In this context, the analysis of the association of reptiles found in the Algora fossil site (Guadalajara Province, Central Spain) is of great interest since it represents the first European Cenomanian site with a high concentration of macrovertebrate remains. A new pythonomorph ‘lizard’ from Algora, Carentonosaurus algorensis sp. nov., is described here. It is the second representative of this European genus. Its microanatomical study reveals that an extreme pachyosteosclerosis affected at least its dorsal vertebrae, suggesting adaptations for slow-swimming habits in shallow-water environments. Consequently, this new taxon is interpreted as a slow swimmer, hovering near the bottom of near-shore marine environments of the Late Cretaceous European Archipelago and, more specifically, along the shores of the larger Iberian Island for that period. This is in concordance with the high diversification of ‘pachyostotic’ pythonomorphs recorded during the Cenomanian, allowing the subsequent adaptation of this lineage to open marine environments.
Four turtle taxa are previously documented from the Cenomanian Arlington Archosaur Site (AAS) of the Lewisville Formation (Woodbine Group) in Texas. Herein, we describe a new side-necked turtle (Pleurodira), Pleurochayah appalachius gen. et sp. nov., which is a basal member of the Bothremydidae. Pleurochayah appalachius gen. et sp. nov. shares synapomorphic characters with other bothremydids, including shared traits with Kurmademydini and Cearachelyini, but has a unique combination of skull and shell traits. The new taxon is significant because it is the oldest crown pleurodiran turtle from North America and Laurasia, predating bothremynines Algorachelus peregrinus and Paiutemys tibert from Europe and North America respectively. This discovery also documents the oldest evidence of dispersal of crown Pleurodira from Gondwana to Laurasia. Pleurochayah appalachius gen. et sp. nov. is compared to previously described fossil pleurodires, placed in a modified phylogenetic analysis of pelomedusoid turtles, and discussed in the context of pleurodiran distribution in the mid-Cretaceous. Its unique combination of characters demonstrates marine adaptation and dispersal capability among basal bothremydids.
We report here Pelomedusoides turtle remains found in the Late Cretaceous deposits of peninsular India. Previously reported from the Upper Cretaceous (Maastrichtian) strata such as the intertrappean beds of Bombay and Kachchh (western India), Raibasa and Kisalpuri (central India), infratrappean Lameta Formation (Pisdura) (central India) and the Kallamedu Formation (southeastern India), and also Early Albian – Middle Turonian beds of the Karai Formation (southeastern India), the new material from the intertrappean beds of Upparhatti (Karnataka state), represents the first record of turtles from southwestern India. It is compared with the previous Cretaceous discoveries from India, which are also reviewed here. The Maastrichtian turtle fauna of India is rich with about nine taxa of Bothremydidae but lacks members of Podocnemididae. The turtle fauna of Upparhatti, consisting of shell, limb, few skull and neck elements, represents about three indeterminate taxa at genus and species level. An analysis of all the Cretaceous turtle taxa of India provided us with an opportunity to review the turtle paleobiogeography in the context of Africa – Madagascar – India land connections.
Turtles are key components of modern vertebrate faunas and their diversity and distributions are likely to be affected by anthropogenic climate change. However, there is limited baseline data on turtle taxonomic richness through time or assessment of their past responses to global environmental change. We used the extensive Triassic–Palaeogene (252–223 Ma) fossil record of terrestrial and freshwater turtles to investigate diversity patterns, finding substantial variation in richness through time and between continents. Globally, turtle richness was low from their Triassic origin until the Late Jurassic. There is strong evidence for high richness in the earliest Cretaceous of Europe, becoming especially high following the Cretaceous Thermal Maximum and declining in all continents by the end‐Cretaceous. At the K–Pg boundary, South American richness levels changed little while North American richness increased, becoming very high during the earliest Palaeogene (Danian). Informative data are lacking elsewhere for this time period. However, the Selandian–Thanetian interval, approximately 5 myr after the K–Pg mass extinction, shows low turtle richness in Asia, Europe and South America, suggesting that the occurrence of exceptional turtle richness in the post‐extinction Paleocene fauna of North America is not globally representative. Richness decreased over the Eocene–Oligocene boundary in North America but increased to its greatest known level for Europe, implying very different responses to dramatic climatic shifts. Time series regressions suggest number of formations sampled and palaeotemperature are the primary influencers of face‐value richness counts, but additional factors not tested here may also be involved.
Araripemydidae is a clade of freshwater pleurodiran turtles originally described in South America, where it is represented by the Brasilian Aptian–Albian Araripemys barretoi. Two potential members of this lineage were defined in an Aptian level of Africa, in Gadoufaoua (Niger): Taquetochelys decorata, described from several isolated plates, and Lagaremys tenerensis, known from an almost complete skeleton. The review of the Araripemydidae record, and the analysis of the intraspecific variability present in that and in other clades of Pleurodira, allow me to refute their attribution to two different forms. ‘L. tenerensis’ is here recognized as a junior synonym of T. decorata. Therefore, the priority of T. decorata is demonstrated, as well as its attribution to Araripemydidae. The almost complete skeletal anatomy of the two currently recognized members of this Aptian–Albian clade (i.e. the African T. decorata and the South American A. barretoi) is well known, which is uncommon for the Cretaceous pleurodiran turtles.
Purpose
The record of fossil turtles of the Iberian Peninsula is abundant and diverse, considering both the Mesozoic and the Cenozoic forms. The knowledge about the Iberian representatives has been significantly improved through the studies carried out in recent years. More than a third of the species nominated in the Iberian record have been described in the 21st century, corresponding to more than half of the currently valid species defined there. These recent studies allowed to recognize unknown lineages for the Iberian record, to refute several attributions or the validity of several taxa, to raise new hypotheses about the palaeobiogeographical and biostratigraphic distributions of several linages, as well as to provide new data on their dispersal events to Europe and, more specifically, to the Iberian Peninsula. Several previous determinations were not reviewed so far, and the validity of several taxa was not evaluated. Thus, the hypotheses about their systematic positions were not updated.
Methods
The information on the diversity of the Iberian turtles is collected and evaluated here. Some synonyms are supported or proposed here, the phylogenetic position of several forms is revised, and all the Iberian taxa, which are revised here, are figured.
Results
The evolutionary history of the turtles of the Iberian Peninsula, from the Upper Jurassic to the present, is compiled, evaluated and synthesized for the first time.
Conclusions
The palaeobiogeography and the information on the origin of each of the lineages of turtles recognized here are considered, as well as the knowledge on their temporal distributions.
The relatively complete and well preserved shell of a turtle, from the middle Cenomanian of Nazaré (Portugal), is studied here. It is recognized as a member of the crown group Pleurodira and, more specifically, the Bothremydidae. Pleurodira are one of the two lineages of modern turtles, their origin being in Gondwana. Pleurodira are very abundant in the uppermost Cretaceous record of Europe. However, this new finding is one of the few occurrences in the lower Upper Cretaceous of Laurasia. A single member of Bothremydidae had so far been identified in Portugal: the late Campanian-early Maastrichtian Rosasia soutoi. It is the only Cretaceous turtle that is endemic to that country both at specific and at generic levels, being exclusive of Portugal. The taxon from Nazaré is identified as Algorachelus peregrinus, this form is also present in the contemporaneous beds in Spain, and is the oldest member of Bothremydidae in Laurasia. Algorachelus peregrinus is confirmed here to be a coastal form, which facilitated its spread. The two oldest known bothremydids from Laurasia, the European A. peregrinus and the North American Paiutemys tibert, are compared for the first time. They are recognized as closely related taxa. This study provides new data allowing a more precisely characterization of the oldest so far known dispersal event of Pleurodira in Laurasia, which was performed by an African lineage of Bothremydidae that reached the east coast of the Atlantic Ocean at least in the middle Cenomanian, and the west region of that Ocean at least in the late Cenomanian.
A turtle skull from the Cretaceous (Cenomanian ?) of the Hamada du Guir, in southern Morocco is described as a new pleurodiran taxon, Hamadachelys escuilliei. This is one of the oldest members of the subfamily Podocnemidinae and it is close to the South American genus Podocnemis.
The mid-Cretaceous vertebrate assemblage from south-eastern Morocco is one of the most diversified continental vertebrate assemblages of this time worldwide. The bony fish component (coelacanths, lungfishes and ray-finned fishes) is represented by relatively complete specimens and, mostly, by fragmentary elements scattered along 250 kilometres of outcrops. Here we revisit the bony fish assemblage by studying both isolated remains collected during several fieldtrips and more complete material kept in public collections. The assemblage comprises several lungfish taxa, with the first mention of the occurrence of Arganodus tiguidiensis, and possibly two mawsoniid coelacanths. A large bichir, cf. Bawitius, is recorded
and corresponds to cranial elements initially referred to ‘Stromerichthys’ from coeval deposits in Egypt. The ginglymodians were diversified with a large ‘Lepidotes’ plus two obaichthyids and a gar. We confirm here that this gar belongs to a genus distinctive from Recent gars, contrary to what was suggested recently. Teleosteans comprise a poorly known ichthyodectiform, a notopterid, a probable osteoglossomorph and a large tselfatiiform, whose cranial anatomy is detailed. The body size and trophic level for each taxon are
estimated on the basis of comparison with extant closely related taxa. We plotted the average body size versus average trophic level for the Kem Kem assemblage, together with extant marine and freshwater assemblages. The Kem Kem assemblage is characterized by taxa of proportionally large body size, and by a higher average trophic level than the trophic level of the extant compared freshwater ecosystems, but lower than for the extant marine ecosystems. These results should be regarded with caution because they rest on a reconstructed assemblage known mostly by fragmentary remains. They reinforce, however, the
ecological oddities already noticed for this mid-Cretaceous vertebrate ecosystem in North Africa.
Diplodocidae are among the best known sauropod dinosaurs. Several species were described in the late 1800s or early 1900s from the Morrison Formation of North America. Since then, numerous additional specimens were recovered in the USA, Tanzania, Portugal, and Argentina, as well as possibly Spain, England, Georgia, Zimbabwe, and Asia. To date, the clade includes about 12 to 15 nominal species, some of them with questionable taxonomic status (e.g., ‘Diplodocus’ hayi or Dyslocosaurus polyonychius), and ranging in age from Late Jurassic to Early Cretaceous. However, intrageneric relationships of the iconic, multi-species genera Apatosaurus and Diplodocus are still poorly known. The way to resolve this issue is a specimen-based phylogenetic analysis, which has been previously implemented for Apatosaurus, but is here performed for the first time for the entire clade of Diplodocidae.
The analysis includes 81 operational taxonomic units, 49 of which belong to Diplodocidae. The set of OTUs includes all name-bearing type specimens previously proposed to belong to Diplodocidae, alongside a set of relatively complete referred specimens, which increase the amount of anatomically overlapping material. Non-diplodocid outgroups were selected to test the affinities of potential diplodocid specimens that have subsequently been suggested to belong outside the clade. The specimens were scored for 477 morphological characters, representing one of the most extensive phylogenetic analyses of sauropod dinosaurs. Character states were figured and tables given in the case of numerical characters.
The resulting cladogram recovers the classical arrangement of diplodocid relationships. Two numerical approaches were used to increase reproducibility in our taxonomic delimitation of species and genera. This resulted in the proposal that some species previously included in well-known genera like Apatosaurus and Diplodocus are generically distinct. Of particular note is that the famous genus Brontosaurus is considered valid by our quantitative approach. Furthermore, “Diplodocus” hayi represents a unique genus, which will herein be called Galeamopus gen. nov. On the other hand, these numerical approaches imply synonymization of “Dinheirosaurus” from the Late Jurassic of Portugal with the Morrison Formation genus Supersaurus. Our use of a specimen-, rather than species-based approach increases knowledge of intraspecific and intrageneric variation in diplodocids, and the study demonstrates how specimen-based phylogenetic analysis is a valuable tool in sauropod taxonomy, and potentially in paleontology and taxonomy as a whole.
Neochelys is a European Eocene genus of turtles well represented by various species. It is one of the few members of Pleurodira identified during the Cenozoic of this continent. However, it has generally been recognized only by shells, and too few skulls are known to provide useful data for comparative diagnosis and relationships. The European Eocene ‘Papoulemys’ had been proposed as a junior synonym of Neochelys, the species ‘P.’ laurenti becoming N. laurenti, but this hypothesis was insufficiently justified. A second skull of this species, from its type locality (the French locality of Saint-Papoul), is analysed here together with several unpublished skulls of other Neochelys spp. from various countries and ages, providing new arguments to refute the validity of the characters used to diagnose ‘Papoulemys’ as a genus distinct from Neochelys. They are exclusively cranial characters since only its holotype (a skull) was known. Several shells from the type locality, on which the reattribution to N.
laurenti had been proposed (but only synthetically), are also studied in detail here, as well as other unpublished Neochelys spp. shells. We propose a new diagnosis for ‘Papoulemys’ laurenti, reallocating the species to Neochelys. We also expand the available information on this genus and on several of its representatives.
Lately, solemydid turtles have been repeatedly recovered as stem Testudines, indicating that they belong to neither one of the two major branches of crown turtles, the Pancryptodira and Panpleurodira. Despite their wide temporal (Late Jurassic to Late Cretaceous) and spatial (North America and Europe) distributions, solemydid turtles are not particularly well known, as exemplified by the fact that only a single skull has been described for the whole group so far. Furthermore, the palaeoecology of solemydid turtles is still contested with hypotheses ranging from semi-aquatic to terrestrial lifestyles. However, the habitat preference of stem Testudines, such as solemydids, is important to understand the evolution and early radiation of the turtle crown, which is primitively aquatic. Here we describe the shell bone microanatomy and histological microstructures of solemydid turtles using a broad sample of taxa of different ages and localities, as well as review previous histological accounts, to elucidate the palaeoecology of the group independent of the geological setting and gross anatomy of the fossil finds. Our results indicate that Solemydidae share unique histological features pertaining to their strongly ornamented shell bones, which a) in cases allow taxonomic identification of even small shell fragments and b) unambiguously corroborate a terrestrial lifestyle of its members. The latter further supports a terrestrial lifestyle preference of most representatives of the turtle stem.
Brodiechelys brodiei is an Early Cretaceous turtle from Great Britain, the only species of the genus. This taxon has been shown in recent phylogenies to be closely related to Xinjiangchelyidae and therefore could be the only representative of this group in Europe. Here, we present several specimens from the Early Cretaceous Maestrazgo Basin, in the Iberian Range of Spain attributed to the British genus, and to a new species, Brodiechelys royoi. This discovery shows that, as previously observed with terrestrial turtles, some freshwater turtle taxa had a wide European distribution during the Early Cretaceous, being present in both Britain and the Iberian Peninsula. This study sheds new light on the phylogenetic position of this enigmatic genus, supporting its attribution to Xinjiangchelyidae, a clade whose presence has been previously confirmed exclusively from the Middle Jurassic to Early Cretaceous of Asia. We propose that another recently identified taxon from the Iberian Peninsula (i.e., Larachelus morl...
We report a new pleurodiran turtle from the Barremian Morro do Chaves Formation, Sergipe-Alagoas Basin, Brazil. We tested the phylogenetic position of Atolchelys lepida gen. et sp. nov. by including it in a
comprehensive cladistic analysis of pleurodires. The new species is a basal member of Bothremydidae and simultaneously the oldest unambiguous crown Pleurodira. The biogeographic and chronostratigraphic significance of the finding has implications for the calibration of molecular clocks studies by pushing back the minimum age of crown Pleurodira by more than 12 Ma (ca 125 Ma). The reanalysis of Pelomedusoides relationships provides evidence that the early evolution and relationships among the main lineages of side-necked turtles can be explained, at least partially, by a sequence of
vicariance events.
The continental deposits of the Upper Cretaceous (Santonian) Csehbánya Formation of the Bakony Mountains in Hungary yielded abundant remains of a bothremydid side-necked turtle, which are attributed to a new species of the genus Foxemys, Foxemys trabanti. F. trabanti shows strong affinities with the European monophyletic group Foxemydina owing to the absence of pits in the upper and lower triturating surfaces, the exclusion of the jugal from the triturating surface, the separation of the Eustachian tube and the stapes by a narrow fissure, the presence of deep and narrow fossa pterygoidei, the partially closed foramen jugulare posterius and the pentagonal shape of the basisphenoid in ventral view. Among the Foxemydina the bothremydid from Iharkút is more closely related to F. mechinorum than to Polysternon provinciale from the Early Campanian of France, mainly because of the position of the occipital condyle relative to the mandibular condyles of the quadrate. The new remains represent the only record of the Foxemydina outside of Western Europe and provide the earliest known occurrence of this endemic, freshwater group in the former Mediterranean Basin. The historical biogeography of the tribe Bothremydini is investigated and a hypothesis of migration from Africa to North America via the high-latitude Thulean route is put forward.
The turtle fauna of Laño includes four taxa which are known only from a restricted area in the late Campanian-
Maastrichtian of southern France and northern Iberian Peninsula. They are compared to other turtles of the world
and their relationships are studied by means of a short cladistic analysis. One is a cryptodire, Solemys, the latest
representative of a Laurasian Jurassic and Cretaceous family (Solemydidae), only known in western Europe at
Cretaceous times. European solemydids are revised and a new species of the genus Helochelydra, H. nopcsai,
is erected for the material from the Wealden (Lower Cretaceous) of the Isle of Wight, England. The other Laño
turtles are pleurodires: Dortoka is a representative of a primitive group (Dortokidae) considered as European in
origin; Polysternon and ?Elochelys are bothremydids and they probably come from the northern part of Africa,
where the family originates during the Early Cretaceous. All the genera are not known after Maastrichtian but
the Bothremydidae and Dortokidae persist in the Tertiary.
Key-words: Chelonians, Late Cretaceous, Iberian Peninsula, Endemism, New taxon, Ecology, Phylogenetic
relationships, Palaeobiogeography.
Late Cretaceous turtle material, excavated in 1979 and 1980 in the Western Desert, Egypt, is described and phylogenetically examined. The turtle association of the Maastrichtian part of the Ammonite Hill Member of the Dakhla Formation comprises at least six taxa. Apart from one undetermined cryptodiran chelonioid specimen, all of them are pleurodiran bothremydid turtles. They include new taxa of three important lineages of the family Bothremydidae. Namely the cosmopolitan Bothremys (Cretaceous) and Taphrosphys (Cretaceous-Tertiary) groups and the Nigeremys group, a group exclusively known from the northern part of Africa at Maastrichtian and possibly at early Paleogene. Therefore, the Egyptian turtles represent the most diverse bothremydid assemblage known so far. The palaeoenvironmental and palaeogeographical significance of the Maastrichtian turtle fauna of Egypt is emphasized.
The five major phases in the palaeontological history of African chelonians are presented:
1) autochthonous development of the north Gondwanian pleurodires from a Pangean source group; 2) littoral expansion of a member of this group (Bothremydidae), accompanied by the arrival of Laurasian marine turtles; 3) in situ development of pleurodires and the immigration of Eurasian cryptodires (Oligo Miocene) traversing the Tethys in several waves; 4) great diversification and endemism (Pliocene to Holocene); 5) important faunal reduction due to climatic changes at the end of the Holocene times (cooling, aridification); elsewhere, great speciation and arrival during the Present of the last European immigrant in the north. Throughout the considered period, there were several reductions in taxonomic diversity and emigrations from Africa. A preliminary catalogue of the fossil record of African chelonians is given, presented according to countries and followed by a taxonomic listing
A new species of podocnemidid pleurodire turtle, Bairdemys
healeyorum, is described from the upper Oligocene Chandler Bridge Formation of South Carolina, USA, on the basis of a nearly complete shell found with associated skull fragments, lower jaw, girdle elements, and limb elements. This is the first record of an Oligocene pleurodire turtle from North America. The shell and lower jaw are unique in detail but similar in overall morphology to equivalent parts of Bairdemys
venezuelensis and B. sanchezi. The plastron of this new species also shares many features with the previously described Maryland Miocene species of podocnemidid, “Taphrosphys” miocenica, so the Miocene taxon is here referred to Bairdemys. In the Oligocene and Miocene, North and South America were separated by broad expanses of salt water, so Bairdemys probably was salt-water tolerant and reached North America by “island hopping” from South America across the Caribbean Sea.
A new turtle, Puentemys mushaisaensis, from the middle to late Paleocene Cerrejó n Formation of Colombia, is described on the basis of a partial skull and many partial to nearly complete carapaces and plastrons representing multiple ontogenetic stages. Whereas P. mushaisaensis is unique in aspects of its shell morphology, it shares many diagnostic characteristics of bothremydid pleurodirans, including a long exoccipital-quadrate contact, a very low and rounded almost circular carapace, and a thinner internal bone cortex than that of the external cortex in both the carapace and plastron. With a maximum carapacial length of 151 cm, P. mushaisaensis is the largest known bothremydid turtle and represents the first occurrence of bothremydids in the Paleogene of South American tropics. Results from a cladistic analysis of bothremydids indicate that P. mushaisaensis shares a close relationship with Foxemys mechinorum from the Late Cretaceous of Europe, indicating a wide-spread geographical distribution for bothremydines during the Late Cretaceous–Paleocene.
The Paleocene Teberemt Formation south of the Adrar des Iforas Mountains, between Saguirilidad and In Fargas, Mali, yielded a nearly complete skull of a new genus and species of side-necked turtle, Acleistochelys maliensis. Acleistochelys is a member of the family Bothremydidae Baur, 1891, because: 1 the fossa precolumellaris is absent, 2 the foramen stapedio-temporale faces anteriorly, 3 the eustachian tube is separated from the stapes by bone, and 4 an exoccipital-quadrate contact is present. Within the Bothremydidae, Acleistochelys belongs to the tribe Taphrosphyini because: 1 the maxilla-quadratojugal contact is absent, 2 the palate is dorsally arched, 3 there is only a small contribution of the palatine to the triturating surfaces, and 4 the septum orbitotemporale is at least partially open. Acleistochelys is most closely related to Azabbaremys because both share a narrow vomer lacking a posterior attachment to the palatines. The specimen was found in a marine limestone associated with crocodiles, echinoids, and mollusks.
The early Cretaceous Santana Formation exposed on the Chapada do Araripe in Ceará State, northeastern Brazil, has yielded remains of a side-necked turtle, Cearachelys placidoi, new genus and species. Cearachelys is based on two skeletons, each consisting of articulated shell, associated skull, and postcrania in varying degrees of completeness. Cearachelys is a pelomedusoid pleurodire belonging to the family Bothremydidae Baur, 1891, based on these bothremydid characters: (1) precolumellar fossa absent, (2) occipital condyle consisting only of exoccipitals, (3) foramen stapedio-temporale anteriorly facing, and (4) exoccipital contacts quadrate. Within the Bothremydidae, Cearachelys is best resolved as the sister group of Bothremys, Rosasia, Foxemys, Zolhafah, and Polysternon. Cearachelys differs from the other two pleurodires in the Santana Formation in the bothremydid characters listed above and in having a quadrate-basioccipital contact, a prootic completely covered in ventral view, and a high lingual ridge on the lower jaw.
The Cenomanian redbeds of southern Morocco have yielded skulls of a new genus and two new species of side-necked turtles, Galianemys whitei and Galianemys emringeri. The genus is based on a series of nine well-preserved skulls and three partial skulls. Galianemys is a pelomedusoid pleurodire belonging to the family Bothremydidae Baur, 1891, because it has: (1) precolumellar fossa absent, (2) foramen stapedio-temporale facing anteriorly, (3) eustachian tube separated from stapes by bone, and (4) exoccipital-quadrate contact. Within the Bothremydidae Galianemys is best resolved as the sister group to Cearachelys because both have the jugal retracted from the orbital margin and a small, slitlike fenestra postotica. Galianemys emringeri has a deep fossa pterygoidei, ventrally exposed prootic, foramen nervi facialis and foramen nervi vidiani, a thicker labial ridge, and the jugal not exposed on the triturating surface, while Galianemys whitei has a shallow fossa pterygoidei, covered prootic and foramen nervi facialis and vidiani, a thinner labial ridge, and a jugal exposed on the triturating surface.
The chelonian fauna of the Portezuelo Formation (Turonian-Coniacian), outcropping at Sierra del Portezuelo (Neuquén province, Argentina), is reported. Two new taxa of pleurodiran turtles are described. One of them is Prochelidella portezuelae new species, a short-necked chelid closely related to extinct species of the Lohan Cura (Albian), Candeleros (Cenomanian), and Bajo Barreal (Turonian) formations from northwestern and central Patagonia, and to the extant species of the genus Acanthochelys . The other is Portezueloemys patagonica new genus and species, a member of the epifamily Podocnemidoidea, and is considered the sister group of the family Podocnemididae. This discovery confirms the coexistence in northwestern Patagonia of a north gondwanan component (Pelomedusoides) and a south gondwanan element (Chelidae) during the Turonian-Coniacian.
The palaeoecology and palaeobiogeography of two Cretaceous selachian genera, Tribodus Brito & Ferreira, 1989 and Pseudohypolophus Cappetta & Case, 1975, are briefly discussed. These two similar-sized taxa developed an analogous pavement-like grinding dentition, characterized by massive teeth with a rhomboidal to hexagonal occlusal surface. Although bath genera appear to have been euryhaline forms, the hybodont Tribodus occurred in fresh/brackish water habitats (e.g. deltas) to shallow marine lagoons, whereas the ray Pseudohypolophus lived in brackish water to coastal marine environments. Palaeobiogeographically, their global distribution displays two distinct but adjoined areas, with Tribodus being present in the northern part of Gondwana (Brazil and North Africa), and Pseudohypolophus occurring on both sides of the North Atlantic (North America and Western Europe). However, the two genera coexisted during Cenomanian times within a small overlap zone, localized in western France. A trophic competition may have arisen from this situation between these two selachians belonging to the same trophic guild. This peculiar situation is well documented within the Cenomanian transgressive series of Charentes (SW France), where a turnover between the two forms is observed (replacement of Tribodus by Pseudohypolophus).
A beautifully preserved skull from the Barremian Wessex Formation of the Isle of Wight, England, represents the first known skull of a European solemydid turtle and is referred to the taxon Helochelydra nopcsai. The cranium is characterized by a number of unique traits, including a greatly reduced dorsal exposure of the prefrontal; pterygoids that completely cover the basisphenoid ventrally; a complete lack of a processus interfenestralis; and fully confluent inner and middle ear cavities. A phylogenetic analysis places Helochelydra nopcsai close to Mongolochelys efremovi, Meiolania platyceps and Kallokibotion bajazidi just outside crown Testudines, but the interrelationships of these four taxa cannot be resolved with confidence. Given that the vast majority of solemydid turtles are known from fragmentary shell material only, we herein develop a series of typological taxon definitions that utilize shell sculpturing and retrieve consistent classes of fragments that originate from specific geological formations. 'Helochelydra' bakewelli and 'Helochelydra' anglica are removed from Solemydidae and tentatively affiliated with the pleurosternid taxon Compsemys. The holotype of the North American Naomichelys speciosa is shown to originate from the Lower Cretaceous (Aptian) Kootenai Formation and the fossil record of this taxon is summarized for the first time. Solemydids are known from the Berriasian-Maastrichtian of Europe and from the Aptian-Campanian of North America. The palaeoecology of solemydid turtles remains ambiguous as the presence of limb osteoderms suggests terrestrial habitat preferences whereas the flattened palate is more typical of an aquatic molluscivore.
An articulated skull and postcranial skeleton of a pelomedusoid turtle, Laganemys tenerensis gen. et sp. nov., is described from the Lower Cretaceous (Aptian–Albian) Elrhaz Formation in Niger. Laganemys has a proportionately long skull, which increases in depth anteriorly, from the occiput to the snout. The thin flat carapace and plastron are covered with fine sulcus-and-ridge texture. The carapace has a deep nuchal embayment anteriorly, a small mesoplastron laterally, and three median fenestrae. The cervical series is nearly as long as the carapace with specialized joints to enhance lateral flexion between cervicals 2 and 3 and cervicals 6 and 7. The relatively long tail is composed of at least 26 vertebrae. Forelimbs and hind limbs have long and relatively straight unguals. Discovered in a fluvial setting, Laganemys would have been an adept long-necked aquatic predator in still waters. A suite of derived features unites Laganemys tenerensis with Araripemys barretoi, a pelomedusoid from northeastern Brazil of similar form, habits and geologic age. These genera provide additional evidence of faunal exchange between South America and Africa in the mid Cretaceous (ca. 110 Mya) prior to the advent of deep waters in the central Atlantic Ocean.
Postcranial material corresponding to three specimens of freshwater turtles, from the lower Albian (upper Lower Cretaceous) of Arino (Teruel Province, Spain), is analysed in this paper. This study allows us to identify the presence of Pleurosternidae (Paracryptodira) outside its known stratigraphic range, from Kimmeridgian to Barremian, and extends its distribution to the Albian. The species from Arino represents a new taxon, Toremys cassiopeia gen. et sp. nov., which is the only pleurosternid described so far in post-Berriasian levels. Toremys cassiopeia is closely related to other taxa from Europe, to which the Cretaceous pleurosternids are restricted. Knowledge about the European freshwater turtle faunas distributed between the Barremian and the uppermost Cretaceous is very limited. The new finding provides relevant data on these poorly understood faunas.
We describe new remains of the enigmatic Late Cretaceous crocodyliform Doratodon carcharidens coming from the Santonian Csehbánya Formation of Hungary. The material includes isolated upper and lower jaw elements and teeth that represent the earliest occurrence of this genus. Previous reports of Doratodon restricted the range of this taxon to the Campanian–Maastrichtian of the areas that are now Romania, Austria and Spain. Using data from both the new remains and the type series from the lower Campanian of Austria, our phylogenetic analysis finds D. carcharidens deeply nested within Gondwanan notosuchians as part of the predominantly South American clade Sebecosuchia. The suggested affinity of D. carcharidens is generally in agreement with previous cladistic assessments and confirms the presence of Gondwanan faunal elements in the Late Cretaceous western Tethyean archipelago (the region that is now southern Europe). Together with published reports on Gondwanan tetrapod immigrants from the Barremian, Albian, Cenomanian and Santonian of Europe this record is not compatible with a recently proposed paleobiogeographical model predicting a post-Hauterivian separation of Europe from Africa and subsequent biogeographical reconnection in the Campanian lasting till the Eocene. Instead, the European fossil record suggests that episodic faunal and geographical links were retained with Gondwana during most of the Cretaceous.
The Spanish town of Galve (Teruel) is notable because of the abundance of Upper Jurassic and, especially, Lower Cretaceous vertebrates recorded there. Although most groups have been studied in detail, information on turtles is very limited even though the material is relatively abundant. So far, no turtle taxa have been identified at the generic level. The only Lower Cretaceous articulated specimen from Galve is analysed here. It is identified as a representative of Cryptodira, Galvechelone lopezmartinezae gen. et sp. nov. Galvechelone lopezmartinezae is determined as a taxon belonging to the node that groups the turtles traditionally assigned to ‘Macrobaenidae’ and ‘Sinemydidae’, and other taxa such as the members of Panchelonioidea. This node, very abundant in the Lower Cretaceous of Asia, and with a broad subsequent distribution, has recently been recognized in the Lower Cretaceous of Europe. The diversity of basal members of Eucryptodira in the European Late Jurassic (represented by Thalassemydidae, Plesiochelyidae and Eurysternidae) was high. Owing to a relative scarcity of well‐preserved early Cretaceous turtles from Europe, the knowledge of this group of reptiles is limited. The study of the new turtle from Galve, together with the recently described Hoyasemys jimenezi, and the recently completed review of the enigmatic Chitracephalus dumonii demonstrate that members of the cryptodiran node grouping ‘Macrobaenidae’, ‘Sinemydidae’ and Panchelonioidea were also very diverse in this period.
A fifth turtle from the Lower Cenomanian quarries of'Ein Yabrud (20 km N. of Jerusalem) was found to differ considerably from the previously described new species Podocnemis parva. In view of numerous dissimilarities in shape, proportions, number of certain shell elements and the disposition of sutures and sulci it has tentatively been decided to assign this turtle to a new species, P. judaea n. sp.
A new turtle taxon, Camerochelys vilanovai gen. et sp. nov., from Hauterivian–Barremian levels of the eastern Cameros Basin (La Rioja, Iberian Range, Spain), is proposed here. Elements of the shell corresponding to five individuals are assigned to it. Camerochelys vilanovai is a turtle with a low, oval and longer than wide shell. It is diagnosed by a combination of characters that includes, among others, the presence of an ornamentation pattern, restricted to the medial area of the vertebral scutes, and composed of thin, numerous and poorly developed radiating striations; shallow nuchal notch; short, and more than four times wider than long cervical scute; five vertebral scutes, all of them substantially wider than long, the second and third ones being more than two times wider than long, and the fourth one two times wider than long; sagittal contact of the last pair of costal plates; presence of inframarginal scutes; absence of mesoplastra. Camerochelys vilanovai is identified as a member of Pan-Cryptodira not assigned to Eurysternidae, to the clade including representatives of Paracyptodira and Plesiochelyidae, or to the crown group Cryptodira. This new taxon could be a representative of Xinjiangchelyidae, a clade belonging to the stem group of Cryptodira, and identified in the Asian and European record. The description of this new taxon further increases the known diversity of turtles in the Early Cretaceous of the Iberian Range, a region where members of several clades of the stem group of Testudines, Pan-Pleurodira and Pan-Cryptodira have been previously identified.
Turtles traditionally identified as basal Eucryptodira members were very abundant and diverse in the European Upper Jurassic. However, the European Cretaceous record of these turtles is poorly known. Brodiechelys brodiei, from the Wealden of the UK, is a turtle traditionally assigned to Eucryptodira. This taxon, recognized on the basis of very little material, has been poorly described and figured. More than a dozen shells are here attributed to B. brodiei. This allows a new diagnosis to be proposed for the taxon, and recognizes that their shells are subject to great intraspecific variability. This conclusion affects many characters used in the diagnosis of taxa defined by scarce material. The analysis of Hylaeochelys, a European Lower Cretaceous taxon traditionally identified as another basal Eucryptodira member, also allows high variability to be observed and several synonyms to be recognized. Hylaeochelys belli is identified here as the only valid species of this genus. Brodiechelys brodiei, H. belli and other European and Asian Jurassic and Lower Cretaceous taxa, previously identified as basal members of Eucryptodira, are incorporated into two hypotheses of phylogenetic relationships. A basal dichotomy in Pancryptodira is obtained. In one of the nodes, taxa traditionally assigned to Paracryptodira, Plesiochelyidae and H. belli are included. The other node groups B. brodiei, taxa traditionally assigned to “Xinjiangchelyidae”, and the Cryptodira members. This study shows a high diversity of Pancryptodira members in the Lower Cretaceous of Europe, assigned to several nodes. Representatives of Paracryptodira, other members of the node grouping the traditional members of Plesiochelyidae and Paracryptodira, and several members of the node grouping Xinjiangchelys latimarginalis and Cryptodira are identified.
Chupacabrachelys complexus, n. gen. n. sp., is an unusual bothremydid pleurodire of the tribe Taphrosphyini found in the Campanian Aguja Formation in the Big Bend region of West Texas. The type example is one of the most complete bothremydid specimens known. Its skull and lower jaw are very narrow, triangular, and dorsoventrally compressed, with the coronoid process posterior to midlength of the jaw. The orbits are elongate anteroposteiorly with narrow extensions along the maxilla-prefrontal sutures, and rugose maxillary projections at the anterolateral corners of orbits. Its reduced temporal emargination, weak posteroventral flange on the squamosal, weak lateral extension of the squamosal along the quadrate suture, and posteroventral knob on opisthotic suggest affinity with Taphrosphyini. The shell has six neurals and a nuchal with sharp midline embayment, and is nearly identical to those of Chedighaii and Bothremys. Chupacabrachelys provides additional evidence for the dramatic evolutionary radiation of bothremydid turtles in tropical paralic environments during Late Cretaceous time.
A new species, Podocnemis parva, from Upper Cenomanian quarries of 'Ein Yabrud (20 km N of Jerusalem), is described on the basis of three nearly complete shells. Comparisons with other members of this and related genera, from the Old and New Worlds, reveal that relatively it is closest to the N American Cretaceous forms.
Although the Bothremydidae are the most abundant and diverse group of turtles in the Upper Cretaceous fauna of Europe, the record attributed to the genus Elochelys was, until now, quite scarce. However, the revision of the specimens previously attributed to this taxon and the analysis of new material from the Spanish record significantly increase our knowledge of these turtles. Evaluation of the morphological variability, affecting many characters that have been considered diagnostic until now and comparisons with other members of the node Bothremydini, allow us to amend the diagnosis of the genus Elochelys, recognising Elochelys perfecta as a valid single species and reassigning its other representative, “Elochelys” convenarum, to the new genus Iberoccitanemys.
A new Cenomanian fossil site has been located in Algora, in the Castilian Branch of the Iberian Ranges, central Spain. The outcrop is in the upper part of the Utrillas Formation in sediments that can be interpreted as sandy coastal deposits (bars and channels) with subtidal and intertidal events. The vertebrate fauna associated with this site is composed of mixed remains of fishes, turtles, crocodyliforms and dinosaurs, with Laurasian and Gondwanan affinities. The discovery of this site provides new palaeobiogeographical information and enriches the poorly known vertebrate faunas of the European Cenomanian.
Although pleurodires have been considered significantly less diverse than their sister group, the cryptodires, current discoveries show that pleurodires had a more complex and extensive evolutionary history than had been realized. Previously unknown radiations, particularly in the near-shore marine realm, are revealed by taxa with diverse cranial morphology, indicating many different feeding and sensory strategies. The pleurodire group that is changed the most by the new discoveries is its largest group, the hyperfamily Pelomedusoides. The hyperfamily Pelomedusoides now consists of the families Pelomedusidae, Podocnemididae, Bothremydidae, Araripemydidae, and Euraxemydidae, new family. The families Bothremydidae, Araripemydidae, and Euraxemydidae, new family, are documented with descriptions of skulls, lower jaws, and shells. The relationships of the family Podocnemididae to its sister taxa Hamadaehelys and Brasilemys are recognized by placing them in the epifamily Podocnemidinura. The epifamily Podocnemidinura is the sister group to the family Bothremydidae, and together they form the superfamily Podocnemidoidea.
A new genus, Bairdemys, is erected for two species of side-necked turtles. Bairdemys venezuelensis (Wood and Díaz de Gamero, 1971) from the late Miocene Urumaco Formation of Venezuela is represented by four skulls and a number of shells. Bairdemys hartsteini from the Miocene of Puerto Rico is known from a skull. Bairdemys is a member of the Podocnemididae because it possesses a cavum pterygoideus, and is related to the Shweboemys Group because it has a well-developed secondary palate. It differs from all other Podocnemididae in having large ventral convexities on the secondary palate, the eustachian tube separated by bone from the fenestra postotica, and the frontal and prefrontal strongly convex dorsally.
The main features of the phylogeny program TNT are discussed. Windows versions have a menu interface, while Macintosh and Linux versions are command-driven. The program can analyze data sets with discrete (additive, non-additive, step-matrix) as well as continuous characters (evaluated with Farris optimization). Effective analysis of large data sets can be carried out in reasonable times, and a number of methods to help identifying wildcard taxa in the case of ambiguous data sets are implemented. A variety of methods for diagnosing trees and exploring character evolution is available in TNT, and publication-quality tree-diagrams can be saved as metafiles. Through the use of a number of native commands and a simple but powerful scripting language, TNT allows the user an enormous flexibility in phylogenetic analyses or simulations.
© The Willi Hennig Society 2008.
Abstract— A new method for weighting characters according to their homoplasy is proposed; the method is non-iterative and does not require independent estimations of weights. It is based on searching trees with maximum total fit, with character fits defined as a concave function of homoplasy. Then, when comparing trees, differences in steps occurring in characters which show more homoplasy on the trees are less influential. The reliability of the characters is estimated, during the analysis, as a logical implication of the trees being compared. The “fittest” trees imply that the characters are maximally reliable and, given character conflict, have fewer steps for the characters which fit the tree better. If other trees save steps in some characters, it will be at the expense of gaining them in characters with less homoplasy.