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A new edentulous pterosaur from the Cretaceous Kem Kem beds of south eastern Morocco
Abstract
A new genus and species, Xericeps curvirostris gen. et sp. nov., is erected for a highly distinctive pterosaur mandible from the mid-Cretaceous (?Albian to lower Cenomanian) Kem Kem beds of south east Morocco. The new taxon is referred to Azhdarchoidea based on the absence of teeth, slenderness of its mandible with sulcate occlusal surface, presence on the posterior section of the mandibular symphysis of short paired ridges bounding a central groove, and the presence of elongate foramina on its occlusal and lateral surfaces. A slight dorsal curvature determines it as a distinct genus of azhdarchoid, as does an autapomorphy: the presence of a continuous longitudinal groove on the ventral midline of the mandibular symphysis. The new species brings to three the number of named pterosaurs from the Kem Kem beds and together with an unnamed tapejarid, points to a relatively diverse pterosaur assemblage in these deposits.
... Here, we report on an important new opportunity to test the hypotheses outlined above. This is provided by the collection, over the last two decades, of substantial numbers of specimens (400þ) of pterosaurs from the Kem Kem Group of Morocco (Kellner and Mader, 1996;Mader and Kellner, 1999;Wellnhofer and Buffetaut, 1999;Rodrigues et al., 2006Rodrigues et al., , 2011Kellner et al., 2007;Ibrahim et al., 2010;Martill and Ibrahim, 2015;Martill et al., 2018Martill et al., , 2020Jacobs et al., 2019Jacobs et al., , 2020McPhee et al., 2020;Smith et al., 2020). Systematic studies of this assemblage have recognised nine named taxa (see Table S1) representing at least four distinct clades of pterodactyloid pterosaurs: Azhdarchidae, ?Chaoyangopteridae, Ornithocheiridae and Tapejaridae . ...
... The material described here was collected by local fossil collectors near the oasis of Hassi el Begaa, Errachidia Province ( Fig. 1), south-eastern Morocco, who excavate a series of vertebrate rich horizons in the upper part of the Ifezouane Formation of the Kem Kem Group (Martill et al., 2018). The age of the Kem Kem Group remains to be determined precisely but is usually regarded as 'mid' Cretaceous, with age estimates ranging from the Albian to the Cenomanian . ...
... The age of the Kem Kem Group remains to be determined precisely but is usually regarded as 'mid' Cretaceous, with age estimates ranging from the Albian to the Cenomanian . For details of the geological setting, stratigraphy, sedimentology, palaeoenvironments and fossil content of this deposit see Martill et al. (2018) and Ibrahim et al. (2020) and references therein. ...
Pterosaurs reached only modest sizes in the Triassic-Jurassic. By contrast, the Cretaceous saw a trend toward large to giant size (2 m to >6 m wingspans), and while small-medium (<1 m to 2 m wingspans) sized forms are known from the Lower Cretaceous they are rare in the Upper Cretaceous. This pattern has been ascribed to the appearance of birds in the mid-Mesozoic, and their displacement of pterosaurs from niches previously occupied by small-medium sized forms. Here we show how new finds of small-very small pterosaurs (<1 m wingspans) from the mid-Cretaceous Kem Kem Group of Morocco point to several sampling biases of the data upon which these patterns are founded. Evidence for the size range of these pterosaurs strongly correlates with sample-size: as the sample increased (from <100 to >400 specimens) both very small and giant forms have been discovered. Histological analysis suggests that very small/small morphs are immature individuals rather than species in which adults were small-bodied. This new data shows that size distribution patterns based on all available specimens differ markedly from those based on a much more restricted sub-set of named taxa. Critically, this analysis reveals that pterosaur size ranges in the Cretaceous do not reflect a switch to large and giant size, but an extension of the size range from very small through to giant forms. Cretaceous niches previously occupied by small pterosaurs in the Triassic and Jurassic were increasingly occupied not by birds but by early ontogenetic stages of large and giant pterosaurs.
... According to Martill et al. (2018) and Ibrahim et al. (2020), Alanqa would be closely related to Xericeps on the basis of FSAC-KK 4000, which is a jaw fragment only tentatively referred to Alanqa (Martill and Ibrahim, 2015) and that bears strong resemblance to the lower jaw of Xericeps. FSAC-KK 4000 and Xericeps share a pair of occlusal ridges that raise vertically and emarginate a median sulcus, and thus FSAC-KK 4000 could possibly represent a close relative of Xericeps ) despite minor differences (or perhaps even an older ontogenetic stage of the same species?). ...
... There is a high number of indeterminate slender, edentulous jaw tips coming from the Kem Kem Group (Ibrahim et al., 2010Rodrigues et al., 2011), meaning that some of these specimens could belong to unknown azhdarchids. Concerning Argentinadraco and Xericeps, these two taxa have been, originally, interpreted as azhdarchids (Kellner and Calvo, 2017;Martill et al., 2018). Their azhdarchoid affinities were clear, as was their non-tapejarid nature, and ultimately both were tentatively assigned to the Azhdarchidae (Kellner and Calvo, 2017;Martill et al., 2018). ...
... Concerning Argentinadraco and Xericeps, these two taxa have been, originally, interpreted as azhdarchids (Kellner and Calvo, 2017;Martill et al., 2018). Their azhdarchoid affinities were clear, as was their non-tapejarid nature, and ultimately both were tentatively assigned to the Azhdarchidae (Kellner and Calvo, 2017;Martill et al., 2018). Still, it is important to highlight that both Martill et al. (2018) and Kellner and Calvo (2017) were unable to confidently exclude, respectively, Xericeps and Argentinadraco from the Chaoyangopteridae, thus leaving ground for an alternate view of these taxa (as chaoyangopterids instead of azhdarchids, or, yet, as members of an entirely new lineage). ...
Aerotitan sudamericanus, from the Upper Cretaceous of the Neuquén Basin (Patagonia, Argentina), is known from a partial jaw fragment which has been interpreted as either an azhdarchid upper jaw, azhdarchid lower jaw, or thalassodromine upper jaw (as the sister-group of Alanqa). Here, we compare it in detail to upper and lower jaws of taxa belonging to all azhdarchoid lineages. It possesses a lateral angle (angle of divergence between occlusal and apex margins in lateral view) that is too low for an upper jaw of any azhdarchoid group. It further differs from thalassodromine upper jaws in exhibiting a convex occlusal margin (in lateral view), a sulcate occlusal surface, and lacking a sagittal crest. Furthermore, Aerotitan differs from Alanqa in 5 aspects: (1) occlusal margin shape in lateral view (convex in Aerotitan, straight in Alanqa), (2) median dentary eminence shape (slender in Aerotitan, posteriorly expanded in Alanqa), (3) median dentary eminence position (anterior in Aerotitan, close to the posterior end of the symphysis in Alanqa), (4) tomial edges shape (thick and blunt in Aerotitan, thin and sharp in Alanqa), and (5) occlusal surface anterior to the median eminence (cross-section concave in Aerotitan, slightly convex in Alanqa). We also conclude that the holotype of A. sudamericanus is a match for an azhdarchid lower jaw, being extremely similar to that of Mistralazhdarcho. When scored as a lower jaw in our phylogenetic analysis, it is recovered as a close relative of Mistralazhdarcho, in a polytomy that also includes Arambourgiania. In contrast, Alanqa is recovered as the sister-group of Keresdrakon, both located at the base of a broader clade of long-snouted azhdarchoids that also includes chaoyangopterids and azhdarchids, to the exclusion of tapejarines and thalassodromines.
... In some deposits edentulous pterosaurs beak tips appear to have been preferentially preserved, perhaps related to their robusticity, with near triangular cross-sections and thickening of bone in the vertices (Ibrahim et al., 2010;Martill et al., 2018) rendering them relatively resistant to transport damage and compaction. The relative abundance of edentulous jaw tips and mid-length fragments of jaw mean that numerous taxa have been founded on these types of remains (e.g., Tupuxuara Kellner and Campos, 1988;Alanqa Ibrahim et al., 2010; Xericeps Martill et al., ...
... The specimen received only scant attention during the 20th century, largely because it seemed to lack identifying features, and possibly because more spectacular edentulous pterosaur material was being discovered elsewhere (e.g., Lawson, 1975). In the 21st century, a dramatic increase in knowledge of edentulous pterosaurs, based on numerous discoveries around the globe (e.g., Lü et al., 2008;Ibrahim et al., 2010;Novas et al., 2012;Kellner and Calvo, 2017;Martill et al., 2018) rekindled interest in the taxonomic relevance of Ornithostoma, and works aimed at resolving its taxonomic identity and history appeared (e.g., Unwin, 2001;Averianov, 2012). Unwin prepared photographs of the holotype specimen of Ornithostoma sedgwicki for his PhD thesis (1991) but neither these, nor other photographs of the specimen have yet been formally published. ...
... The absence of evidence for the anterior margin of the nasoantorbital fenestra or divergence of the mandibular rami makes it difficult to determine whether the jaw fragment pertained to the rostrum or the mandibular symphysis. This is a recurring problem, and applicable (for example) to all edentulous pterosaurs described from the Kem Kem Group of Morocco (Ibrahim et al., 2010;Martill et al., 2018Martill et al., , 2020aMcPhee et al., 2020). ...
A re-examination of fossil material from the Late Cretaceous Cambridge Greensand Member (CGM) of the West Melbury Marly Chalk Formation revealed a number of new specimens of edentulous pterosaur jaw fragments previously identified as shark fin spines and fish jaws and accessioned under the epithet ‘cestraciontid finray’ and ‘jaws of fish’. These are now recognised as pterosaurian jaw tips and referred to Ornithostoma sedgwicki Seeley, 1891 and Azhdarchoidea indet. This material increases the diversity of edentulous pterosaurs from the CGM.
The edentulous pterosaur Ornithostoma sedgwicki Seeley, 1891 from the Cretaceous Cambridge Greensand of eastern England is reviewed. The holotype specimen is confirmed as a fragment of a premaxilla/maxilla of a non-tapejarid azhdarchoid on account of the conspicuous curvature of the dorsal and occlusal margins posteriorly and the presence of small neural foramina on the lateral margins. Neural foramina are not seen on jaws of members of the Pteranodontia, a group to which O. sedgwicki was included previously. The referral of O. sedgwicki to Azhdarchoidea eliminates the single known Lower Cretaceous occurrence of Pteranodontidae, restricting the temporal range of this taxon to the Upper Cretaceous. Postcranial material referred to O. sedgwicki from the type horizon is regarded as indeterminate Pterosauria.
... 4f ). The latter features have not been reported in any other pterosaur, with the exception of Xericeps curvirostris Martill et al. 2018, suggesting a close relationship between these taxa. The holotype, FSAC-KK 26, appears to belong to an individual with an estimated wingspan of 3-4 m (Ibrahim et al. 2010). ...
... Xericeps. Xericeps curvirostris Martill et al. 2018, is represented by a single fragment of a mandibular symphysis (FSAC-KK 10700) commercially collected from the Douira Formation at Aferdou N'Chaft (Fig. 99). The holotype, described in detail by Martill et al. 2018, is distinguished by its curvature in lateral view, with markedly concave dorsal and convex ventral margins. ...
... Xericeps curvirostris Martill et al. 2018, is represented by a single fragment of a mandibular symphysis (FSAC-KK 10700) commercially collected from the Douira Formation at Aferdou N'Chaft (Fig. 99). The holotype, described in detail by Martill et al. 2018, is distinguished by its curvature in lateral view, with markedly concave dorsal and convex ventral margins. Unique to this pterosaur there is a pronounced midline groove on the ventral border of the mandibular symphysis. ...
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
... At all of these localities fossils are excavated from thin (5 cm to [rarely] 80 cm) event horizons notable for argillaceous rip up clasts, small silicate pebbles and isolated bones and teeth (Fig. 3). Significantly, the matrix of FSAC-KK 5004 does not match that of the well-known site of Hassi El Begaa in the southern Tafilalt (see Martill et al., 2018). ...
... The lateral margins possess a number of small, elongate foramina typical of those seen on members of the Azhdarchoidea (e.g. € Osi et al., 2005;Martill et al., 2018) including Tapejaridae (Wellnhofer and Buffetaut, 1999;Kellner, 2013;Manzig et al., 2014). There is a single row of these foramina on both margins that lie close to and extend parallel Fig. 3. Simplified stratigraphic sequence for the Kem Kem beds in the region around Ikhf N 0 Taqmout. ...
... Afrotapejara is easily distinguished from other Kem Kem beds azhdarchids on account of its conspicuously downturned rostrum. In Alanqa saharica the occlusal margin in lateral view is a straight line, while in Xericeps curvirostris it is upwardly curved (Ibrahim et al., 2010;Martill et al., 2018). In the possible chaoyangopterid Apatorhamphus gyrostega (McPhee et al., 2020) this margin is also straight. ...
A new pterosaur, Afrotapejara zouhri gen. et sp. is described on the basis of a partial rostral fragment from the Cretaceous Kem Kem beds of Takmout, near Erfoud in southern Morocco. The taxon is distinguished from all other Tapejaridae on the possession of a dorsal expansion of the rostral margin a short distance from the rostral tip. Tapejarid features include a downturned rostrum (autapomorphic), edentuly, expansion of the rostral median crest (autapomorphic) and the presence of small foramina on the lateral margins and occlusal surface. The new specimen is the fourth edentulous pterosaur taxon from the Kem Kem beds and is the first unambiguous occurrence of Tapejaridae in Africa.
... In recent years, the Kem Kem beds of Morocco have helped to fill in this gap, providing a record of pterosaur diversity from a middle Cretaceous fluvial ecosystem (Ibrahim et al., 2010;Martill and Ibrahim, 2015;Martill et al., 2018;Jacobs et al., 2019). Although the pterosaur record of southern Morocco consists entirely of isolated bones, it has nevertheless yielded a diverse assemblage. ...
... The Kem Kem beds (an informal term) comprise the lower Ifezouane and upper Aoufous formations. Both formations can be traced for approximately 360 km from Zguilma in the south west to Goulmima in the north (Cavin et al., 2010;Martill et al., 2018). The Kem Kem beds rest with angular unconformity on marine Palaeozoic strata and are capped non-sequentially by Cenomanian transgressive marine carbonates of the Akrabou Formation ( Fig.2) (Ettachfini and Andreu, 2004). ...
... Kem Kem beds pterosaurs, although fragmentary, are remarkably diverse. They include the azhdarchioids Alanqa saharica and Xericeps curvirostris, a possible chaoyanyopterid Apatorhamphus gyrostega, an unnamed tapejarid, and the ornithocheirids Siroccopteryx moroccensis and Coloborhynchus fluviferox (Wellnhofer and Buffetaut, 1999;Mader and Kellner, 1999;Ibrahim et al., 2010;Martill et al., 2018;Jacobs et al., 2019, McPhee et al., 2020. ...
Pterodactyloid pterosaurs underwent a diversification in the Late Jurassic and Early Cretaceous, followed by a major turnover event in the mid-Cretaceous, when ornithocheiroids and basal azhdarchoids were replaced by pteranodontids, nyctosaurids and azhdarchids in the latest Cretaceous. However, precise patterns of turnover are obscured by the incompleteness of the pterosaur fossil record. Fossils from the middle Cretaceous Kem Kem beds of Morocco (?Albian –Cenomanian) have helped shed light on the diversity of pterosaurs from this time and provide a window into the diversity of a continental pterosaur assemblage from this critical transitional period. Two toothed pterosaurs, the ornithocheirids Siroccopteryx moroccensis and Coloborhynchus fluviferox, have been reported from the Kem Kem beds. Here, we report a partial mandible and two premaxillae representing three additional taxa of toothed pterosaurs. The mandibular symphysis closely resembles that of Anhanguera piscator from the Romualdo Member of the Santana Formation of Brazil in the arrangement and spacing of the alveoli, the weak anterior upturn of the jaw, and the ventral crest. One premaxilla closely resembles that of the ornithocheirid Ornithocheirus simus from the Cambridge Greensand Formation of eastern England. A second premaxilla is referred to Coloborhynchus, bearing similarities to C. clavirostris from the Hastings Group of southern England, and C. fluviferox from the Kem Kem beds of Morocco. In total, the Kem Kem pterosaur fauna includes at least nine species, of which three are ornithocheirids. The Kem Kem assemblage supports the idea that toothed pterosaurs remained diverse during the mid Cretaceous before disappearing from post-Cenomanian strata.
... With the exception of the Late Jurassic Tendaguru beds in Tanzania (Reck, 1931;Unwin and Heinrich, 1999;Costa et al., 2015), the majority of African pterosaur material consists of isolated teeth, vertebral fragments and partial limb bones (Swinton, 1948;Dal Sasso and Pasini, 2003), with some associated material reported from the Late Cretaceous (Maastrichtian) of central Morocco (Pereda-Suberbiola et al., 2003;Longrich et al., 2018). Within the last twenty years numerous pterosaur remains have been recovered from the Cretaceous Kem Kem beds of southeast Morocco (Wellnhofer and Buffetaut, 1999;Ibrahim et al., 2010;Rodrigues et al., 2011;Martill and Ibrahim, 2015;Martill et al., 2018;Jacobs et al., 2019), and it is fast becoming one of the most important regions for understanding the diversity and evolution of pterosaurs in Africa (Fig. 1). ...
... The Aferdou N'Chaft mesa and the adjacent Hamada du Kem Kem consist of a~50 m to~90 m thick sequence of mainly Cretaceous (? Albian/Cenomanian) age strata, represented by a series of fluvial, cross-bedded sandstones with thin mudstones and intraformational conglomerates of mudstone rip up clasts (Fig. 2). These strata are informally called the Kem Kem beds, and are overlain by shallow marine carbonates of the Cenomanian-Turonian Akrabou Formation (Ettachfini and Andreu, 2004;Martill et al., 2018). These Cretaceous strata rest with angular unconformity on indurated marine Palaeozoic rocks of mainly Siluro-Devonian age (Fig. 2). ...
... Specimen BSP 1993 IX 338 shows that the rostrum of A. gyrostega is less pointed than that of Pteranodon. Pteranodontians also seem to lack the elongate foramina (Bennett, 2001) that are conspicuous on the jaws of many other, although not all, azhdarchoids ( } Osi et al., 2001; Ibrahim et al., 2010;Martill et al., 2018). A. gyrostega does not appear to be a pteranodontian. ...
A new genus and species of edentulous pterodactyloid pterosaur with a distinctive partial rostrum from the mid-Cretaceous (?Albian/Cenomanian) Kem Kem beds of southeast Morocco is described. The taxon is assigned to Chaoyangopteridae based upon its edentulous jaws, elongate rostrum and slightly concave dorsal outline. The rostral cross-section is rounded dorsally and concave on the occlusal surface. The lateral margins are gently convex dorsally becoming slightly wider toward the occlusal border, and a row of small lateral foramina parallel to the dorsal margin determines it as a taxon distinct from other chaoyangopterids. Apatorhamphus gyrostega gen et sp. nov. is a pterosaur of medium to large size (wingspan likely somewhere between ~3 m and ~7 m). This new species brings the number of named Kem Kem azhdarchoids to three, and the number of named Kem Kem pterosaurs to five, indicating a high pterosaur diversity for the Kem Kem beds.
... 2F1eF2, H1eH2, 4A, C, 5EeF, 6F3eF4), between the lateral rows. Although Martill et al. (2018) considered these foramina-like pits located on the occlusal surface likely to be a synapomorphy of azhdarchoid pterosaurs (but absent in pteranodontoids), their functional morphology is blurry. The ventral margin of the mandibular symphysis is gently curved at its posterior end (Figs. ...
... Consequently, the suggestions of Vremir et al. (2015) that this specimen, illustrated by Jipa-Murzea (2012) is smaller than E. langendorfensis are clearly unfunded and spurious. Compared to PSMUBB V651b (Fig. 6F1eF2, J1eJ2), the mandible of X. curvirostris (FSAC-KK 10700; Martill et al., 2018;Fig. 6J1eJ2) is narrower, both in dorsal and lateral views. ...
... However, both specimens share the U-shaped concave occlusal surface. Martill et al. (2018) noted that the bone surface is smooth to the naked eye in X. curvirostris, a feature suggesting an osteologically mature (or, almost mature) individual. The Ad. tharmisensis mandibular symphysis exhibits a fibrous bone surface, hence indicating an osteologically immaturity, thus a still developing individual at the time of its death. ...
The Upper Cretaceous “Hațeg Island” is not only renowned mostly for its peculiar assemblage of dwarf dinosaurs, but also for its Azhdarchidae pterosaurs including giant specimens (e.g. Hatzegopteryx thambema) and medium-sized ones (e.g. Eurazhdarcho langendorfensis), discovered in the Hațeg and Transylvanian basins of Romania. Here, we report a new species of azhdarchid pterosaur, Albadraco tharmisensis gen. et sp. nov. The material refers to two well-preserved “beak” fragments and a cervical vertebra. These fossils were discovered together in a fossil assemblage in the Maastrichtian Șard Formation, located in the southwestern area of the Transylvanian Basin (Alba District, Romania). The association of a premaxilla and a mandibular symphysis from the same specimen is the first ever reported in Europe. The fourth cervical exhibits the best three-dimensional preservation of any azhdarchid mid-cervical vertebra in Transylvania, as all specimens reported previously are poorly preserved (e.g. in E. langendorfensis) or incomplete like the specimen from Pui with a broken condyle. Albadraco tharmisensis represents a new species of a large–sized azhdarchid from the “Hațeg Island”. Its size fits between that of E. langendorfensis and H. thambema, hence confirming the co-existence of medium, large, and giant–sized azhdarchids during the Maastrichtian in Transylvania. The possibility of Ad. tharmisensis being a young Hatzegopteryx is also discussed.
... The Cretaceous period in the Errachidia-Boudnib-Erfoud Basin (Figure 1) has been the subject of several studies previously initiated in the thirties of the twentieth century as introductory works [1][2][3][4]. These studies were followed by other works that focused on the sedimentology, paleontology, and geochemistry of this basin [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. However, studies that focus on the lateral extent of the formations throughout the basin remain scarce and do not cover the entire basin. ...
Ten detailed sections have been logged and studied from the “Infra-Cenomanian’’ to the Cenomanian–Turonian deposits in the Errachidia–Boudnib–Erfoud Basin between Tazzouguerte and Anounizme(SE Morocco). They show variations in their lithology and microfacies that reflect changes in the depositional environment from the base to the top of the sedimentary record. Indeed, depositional setting grades from a fluvial environment marked by sandstone deposits of the Ifezouane Formation to an alluvial plain and coastal lagoon environment comprising an alternation of red clay, gypsum, and green marl beds of the Aoufous Formation and, finally, towards shallow to moderately deep marine environments with the deposition of the carbonates of the Akrabou Formation. Correlations between the studied sections show variations in the thickness of strata throughout the basin. The variations recorded in the so-called “Infra-Cenomanian” series may be related to the structuration of the basement. The Cenomanian–Turonian carbonate platform shows deeper marine and thicker sediments towards the east, while it thins towards the west until its disappearance in Anounizme. This reflects the global Cenomanian–Turonian transgression in the Errachidia–Boudnib–Erfoud Basin from the eastern Tethyan realm towards the west. The regional correlation of the Errachidia–Boudnib–Erfoud Basin with the Ouarzazate and Agadir basins shows an eastward thinning of the Cenomanian–Turonian marine deposits of Agadir. This suggests the presence of a paleorelief at the Anounizme locality. This could be the boundary between the Errachidia–Boudnib–Erfoud Basin, with Tethyan influence, to the east and those of Ouarzazate and Agadir, with Atlantic affinity, to the west.
... www.nature.com/scientificreports/ references therein) containing an ornithocheirid and at least one lonchodectids; a large and rapidly accumulating assemblage of often incomplete but uncrushed pterosaur bones from the Kem Kem Group of Morocco [15][16][17][18][19][20][21][22][23] with several species of ornithocheirids and azhdarchoids based on jaw remains (Smith et al. in review); incomplete but associated skeletons of an istiodactylid (Mimodactylus), azhdarchoid (Microtuban), and an ornithocheirid from the Sannine Formation of Lebanon 24,25 ; isolated bone fragments of an ornithocheirid, a coloborhynchid, and a lonchodectid from the Cenomanian of European Russia (e.g., 26,27 ); and a few fragments, possibly of azhdarchids, from the Khodzhakul Formation of Uzbekistan [28][29][30][31] . The Hwasun Seoyuri tracksite has yielded about 1,500 dinosaur tracks that form more than 60 trackways distributed across five different horizons 32,33 . ...
Here we describe a new pterosaur footprint assemblage from the Hwasun Seoyuri tracksite in the Upper Cretaceous Jangdong Formation of the Neungju Basin in Korea. The assemblage consists of many randomly oriented prints in remarkably high densities but represents a single ichnotaxon, Pteraichnus. Individuals exhibit a large but continuous size range, some of which, with a wingspan estimated at 0.5 m, are among the smallest pterosaurs yet reported from the Upper Cretaceous, adding to other recent finds which contradict the idea that large and giant forms entirely dominated this interval. Unusual features of the tracks, including relatively long, slender pedal digit impressions, do not match the pes of any known Cretaceous pterosaur, suggesting that the trackmakers are as yet unknown from the body fossil record. The Hwasun pterosaur footprints appear to record gregarious behavior at the exact location by individuals of different ages, hinting at the possibility that pterosaurs gathered in mixed-age groups.
... This phylogenetic analysis coded only the specimens described in Ibrahim et al. (2010) and Martill and Ibrahim (2015) with the exception of BSPG 1993 IX 338, the most defensible action, but much of the material is similar and likely formed a clade if not a species. Alanqa saharica was recovered as a thalassodromine in a clade with Xericeps curvirostris Martill et al., 2018, Argentinadraco barrealensis Kellner and Calvo, 2017, and Leptostomia begaaensis Smith et al., 2020. Slightly elongate cervical vertebrae from the Kem Kem Beds (CMN 50801, FSAC-KK 5077, and LINHM 014) were referred to the Azhdarchidae by Rodrigues et al. (2011) and Williams et al. (2021), but they have unreduced blade-like neural spines indicating that they do not belong to azhdarchids and may represent non-azhdarchid azhdarchiforms instead. ...
The Azhdarchidae have come to be known as the most diverse clade of Late Cretaceous pterosaurs and the largest flying creatures in existence. Since the erection of the taxon nearly four decades ago, many partial specimens have been referred to it from the Early Cretaceous and Late Jurassic, but none of these identifications can be confirmed. The most comprehensive phylogenetic analysis and taxonomy of Pterosauria is presented, and the evolutionary history of the Azhdarchidae is reviewed. As currently known, azhdarchids are restricted to the Late Cretaceous (Turonian–Maastrichtian). Fourteen species are currently included in the Azhdarchidae: Quetzalcoatlus northropi and Q. lawsoni are recovered as sister taxa in a monophyletic Quetzalcoatlus, with Arambourgiania philadelphiae, Hatzegopteryx thambema, a trichotomy with Cryodrakon boreas and Wellnhopterus brevirostris, Zhejiangopterus linhaiensis, Eurazhdarcho langendorfensis, a Phosphatodraco mauritanicus + Aralazhdarcho bostobensis sister group, as well as an Azhdarcho lancicollis + Albadraco tharmisensis + Aerotitan sudamericanus + Mistralazhdarcho maggii clade are recovered as successive outgroups to Quetzalcoatlus in the Azhdarchidae. The previous azhdarchid species Montanazhdarcho minor and Radiodactylus langstoni are recovered as non-azhdarchid azhdarchiforms; Alanqa saharica and Argentinadraco barrealensis are thalassodromines; Cretornis hlavaci and Volgadraco bogolubovi are pteranodontians; and Bakonydraco galaczi is a tapejarine. Up to a dozen pterosaur lineages persist into the latest Cretaceous (Maastrichtian Age) including azhdarchids, pteranodontids, and nyctosauromorphs. In the Late Cretaceous, an ornithocheirid, cimoliopterids, a lonchodrachonid, a lonchodectid, pteranodontians, tapejarines, thalassodromines, a chaoyangopterine, and azhdarchiforms are present. The pterosaurs did not have a terminal decline in diversity and were increasing in species number at the end of the Cretaceous Period.
... Small foramina are present on the jaws of many pterosaurs across a wide range of clades, distributed across various parts of Martill et al., 2018. Averianov (2010 noted such foramina on two specimens referred to the azhdarchid Azhdarcho lanciocollis. ...
The sense of touch is important for hunting and feeding in vertebrates, especially when visual cues are unreliable. Foramina in the jaws and face, associated with nerves and sensory organs, may provide information about feeding. Pterosaurs, many of which had large, well-developed eyes, are often assumed to have been visual feeders. Here, we show that the lonchodectid pterosaur Lonchodraco giganteus (Bowerbank, 1846) has clusters of circular foramina at the anterior mandibular symphysis (the odontoid) and on the lateral margins of the rostrum that indicate enhanced sensitivity of the rostrum tip. This pattern implies tactile feeding. The foramina were likely occupied by Herbst corpuscles or similar integumentary sensory micro-organs (ISO). They presumably served a sensory function at the jaw tip to enhance food gathering. A similar morphology occurs in some avians that feed using tactile cues, including probe feeders such as kiwis, sandpipers, and ibises, tactile hunters such as spoonbills, and filter feeders such as ducks and flamingos. The beak morphology of L. giganteus does not closely resemble that of these birds, and thus its modus operandi for feeding remains speculative, however tactile feeding for fish or invertebrates in shallow water seems likely. Like birds, pterosaurs evolved a diverse range of feeding strategies.
... The majority of ornithocheirid pterosaurs are described from fragmentary cranial elements and are mostly diagnosed based on the position and orientation of the fangs in their jaws and the extent of their cranial crests, even when articulated material is available (e.g. Wellnhofer, 1985Wellnhofer, , 1991bCampos & Kellner, 1985;Lü & Ji, 2005;Wang et al., 2005;Lee, 1994;Lü & Ji, 2005;Averianov, 2007;Myers, 2010;Buffetaut et al., 2010;Elgin & Frey, 2011;Martill, 2015;Martill et al., 2015Martill et al., , 2018. Wing bones, especially the humerus, the carpals and the metacarpal IV, are considered to present marginal diagnostic features but are occasionally used (e.g. ...
... Despite the high diversity of vertebrate fossils in the Kem Kem Group, the anatomy of many of the taxa is poorly understood as vertebrate remains are typically incomplete and isolated (Russell, 1996;Dal Sasso et al., 2005;Martill et al., 2018). Fish remains are extremely numerous in the Kem Kem Group, likely due to their autochthonous origin and high preservation potential of certain elements (e.g. ...
... This is particularly true for pterosaurs, an extinct group of flying reptiles that includes the major powered flying vertebrates for almost 160 mya 2,3 . The main African records of this group are restricted to isolated elements from the Jurassic deposits of Tendaguru 4-6 from Tanzania, and the Upper Cretaceous Kem Kem Beds (Cenomanian) [7][8][9][10][11] and Ouled Abdoun (Maastrichtian) 12,13 from Morocco. The most complete pterosaur specimens from the Afro-Arabian continent have been recovered from Cenomanian marine deposits of Lebanon 14 (Fig. 1). ...
Despite being known from every continent, the geological record of pterosaurs, the first group of vertebrates to develop powered flight, is very uneven, with only a few deposits accounting for the vast majority of specimens and almost half of the taxonomic diversity. Among the regions that stand out for the greatest gaps of knowledge regarding these flying reptiles, is the Afro-Arabian continent, which has yielded only a small number of very fragmentary and incomplete materials. Here we fill part of that gap and report on the most complete pterosaur recovered from this continent, more specifically from the Late Cretaceous (~95 mya) Hjoûla Lagerstätte of Lebanon. This deposit is known since the Middle Ages for the exquisitely preserved fishes and invertebrates, but not for tetrapods, which are exceedingly rare. Mimodactylus libanensis gen. et sp. nov. differs from the other Afro-Arabian pterosaur species named to date and is closely related to the Chinese species Haopterus gracilis, forming a new clade of derived toothed pterosaurs. Mimodactylidae clade nov. groups species that are related to Istiodactylidae, jointly designated as Istiodactyliformes (clade nov.). Istiodactyliforms were previously documented only in Early Cretaceous sites from Europe and Asia, with Mimodactylus libanensis the first record in Gondwana.
... Partial skeletons include a variety of fishes (Cavin et al., 2015), a sauropod dinosaur, Rebbachisaurus garasbae (Lavocat, 1954), and the predatory dinosaurs Deltadromeus agilis and Spinosaurus aegyptiacus (Sereno et al., 1996;Ibrahim et al., 2014). A rich and highly diverse vertebrate assemblage is preserved, consisting of freshwater osteichthyans (Cavin and Brito, 2001;Yabumoto and Uycno, 2005;Forey et al., 2011;Cavin et al., 2015), sharks (Dutheil and Brito, 2009;Martill and Ibrahim, 2012), amphibians (Rage and Dutheil, 2008), turtles (De Broin, 2002;Gaffney et al., 2002Gaffney et al., , 2006, snakes (Klein et al., 2017), crocodyliforms (Larsson and Sues, 2007;Sereno and Larsson, 2009), pterosaurs (Ibrahim et al., 2010;Rodrigues et al., 2011;Martill et al., 2018) and dinosaurs (Sereno et al., 1996;Cau et al., 2012;Mannion and Barrett, 2013;Ibrahim et al., 2014Ibrahim et al., , 2016Wilson and Allain, 2015). In addition, the Kem Kem assemblage also preserves a diverse ichnofauna (Ibrahim et al., 2014), notably rare dinosaur footprints. ...
... The Kem Kem contains a rich fauna including dinosaurs (Russell, 1996;Sereno et al., 1996;Mannion and Barrett, 2013;Chiarenza and Cau, 2016), pterosaurs (Wellnhofer and Buffetaut, 1999;Ibrahim et al., 2010;Martill et al., 2018), crocodiliforms (de Broin, 2002Sereno and Larsson, 2009), turtles (Gaffney et al., 2002(Gaffney et al., , 2006, snakes (Rage and Dutheil, 2008;Klein et al., 2017), amphibians (Rage and Dutheil, 2008), fish , and sharks (Cavin et al., 2010). The fauna includes salt-intolerant species including amphibians and lungfish, as well as large fish and sharks, and semiaquatic crocodylomorphs and turtles. ...
Spinosauridae is a specialized group of theropod dinosaurs characterised by a long, narrow skull, robust forelimbs with a hooked thumb claw, and tall neural spines forming a dorsal sail. The ecology of these unusual dinosaurs has been debated since the original discovery of Spinosaurus aegyptiacus in 1912. Morphological similarities to crocodilians, including tooth shape and an elongated rostrum, indicate a piscivorous diet, and in the giant Spinosaurus, a long body and short limbs suggest semi-aquatic habits. However, the hypothesized aquatic habits of Spinosaurus have been called into question, and the distribution of aquatic habits within Spinosauridae remain unclear. Here, new spinosaurid specimens from the Kem Kem beds of Morocco reveal aquatic adaptations in the cranium. Elevated orbits and bending of the frontals placed the eyes atop the skull, as in semiaquatic animals such as crocodiles and hippos. Two morphologies are present, a smaller morph characterized by narrow, triangular frontals, and a larger morph characterized by broad, subrectangular frontals overlapping the prefrontals. The two morphs suggest two distinct spinosaurine taxa, and are tentatively referred to the spinosaurines Spinosaurus cf. aegyptiacus and Sigilmassasaurus brevicollis, respectively. Semiaquatic habits were widespread within the Spinosaurinae and at least two distinct aquatic spinosaurines inhabited the Cenomanian of North Africa, challenging previous assumptions that non-avian dinosaurs were solely terrestrial. The appearance of giant semiaquatic dinosaurs may have followed the disappearance of giant pholidosaurid crocodylomorphs, suggesting that the extinction of large crocodylomorphs was associated with the rise of dinosaurs as apex predators in the freshwater ecosystem in North Africa.
... In the middle and posterior parts of LPB R.2347, along the dorsolateral margins, there are at least two pairs of widely spaced small foramina-like pits (Fig. 3D). The precise nature and function of these pits are uncertain; in shape and relative size, they resemble the foramina present on the anterior mandibular symphyses of azhdarchoid pterosaurs and considered to represent an apomorphy of this clade (Martill et al. 2018), but are definitively distinct from the tooth alveoli of dentate taxa. ...
We describe and interpret a posterior mandibular symphysis of a very large azhdarchid pterosaur. The specimen LPB (FGGUB) R.2347 exhibits a series of morphological characters present in both azhdarchid and tapejarid pterosaurs, suggesting a more basal position within the clade Azhdarchidae. This fossil was collected from Maastrichtian continental deposits near Vălioara in the Hațeg Basin, Romania, but cannot be confidently referred to the contemporaneous giant Hatzegopteryx thambema, also from Vălioara, due to the absence of overlapping skeletal elements. Remarkably, this mandibular symphysis shares a number of features the smaller azhdarchoid Bakonydraco galaczi from the Santonian of Hungary. Additional comparisons with previously described large‐sized azhdarchid mandibles indicate a certain degree of morphological and probably ecological disparity within the group. This specimen represents the largest pterosaur mandible ever found and provides insights into the anatomy of the enigmatic giant pterosaurs.
Here, we describe the first pterosaur remains from Angola, an assemblage of fourteen bones from the Lower Maastrichtian marine deposits of Bentiaba, Namibe Province. One new species is introduced, Epapatelo otyikokolo, gen. et sp. nov., which comprises an articulated partial left humerus and ulna as well as an articulated left ulna and radius (from a second individual). Phylogenetic analysis confirms a non-nyctosaurid pteranodontian attribution for this new taxon and supports a new apomorphy-based clade, Aponyctosauria, which is here defined. Late Cretaceous pteranodontians are rare in Sub-Saharan Africa and throughout the Southern Hemisphere. Preliminary histological analysis also reveals a likely sub-adult age for one of the specimens. This fossil assemblage provides a first glimpse of Angolan pterosaur paleobiodiversity providing further insight into the Gondwanan ecosystems of the Upper Cretaceous.
A historic specimen described for the first time revealed important autapomorphic characters, permitting the definition of a new species, Javelinadactylus sagebieli gen. n. et sp. n., which represents the second toothless species from the Javelina Formation, Big Bend National Park of West Texas (United States of America). The remains of J. sagebieli (Azhdarchoidea: Tapejaridae) were found in 1986, but were never properly studied, and its taxonomic affinity remains undefined. The description is based on a partially articulated skull and mandible, which offer information on the anatomy of a single azhdarchoid pterosaur. J. sagebieli exhibit a large nasoantorbital fenestra, a rostral index of medium value and is assigned to the clade Thalassodrominae, a group of tapejarid pterosaurs that were reported exclusively from the Romualdo Formation of Brazil, with only two genera known. Thalassodromines are characterized by a typical cranial configuration with toothless jaws and a high and wide premaxilla bar, formed by sub-parallel or parallel borders. The new specimen described here represents the first record of the Tapejaridae group in the Maastrichtian of North America, and the cranial morphology of the new taxon increase the richest of the diversity of the azhdarchoid pterosaurs during the end of the Late Cretaceous, suggesting that the tapejarids were still diversifying in the Maastrichtian.
A new locality near Tarda on the northern margin of the Tafilalt, south eastern Morocco exposes extensive sequences of the Ifezouane and Aoufous formations of the fluvial Kem Kem Group (Cretaceous, ?Albian-Cenomanian) on the south western flank of Ikfh n’Oufza escarpment of the Hamada du Meski. The stratigraphic sequence here differs significantly from better known exposures of the Kem Kem Group in the southern Tafilalt, and includes a heterolithic sequence of alternating grey mudstones and fine sandstones and a thin (∼1.5 m) marine limestone. The locality is noteworthy for three vertebrate-bearing horizons within the upper part of the Ifezouane Formation. The upper two (Sites 1 and 2 in ascending order) are dominated by dental remains of the sawfish Onchopristis and the aquatic theropod dinosaur Spinosaurus. Significantly, the remains of terrestrial dinosaurs constitute less than 1 % of the total dental assemblage at Site 1 and 5.6% at Site 2. At Site 2 teeth of Spinosaurus outnumber the rostral “teeth” of Onchopristis. The remarkably high abundance of spinosaur teeth compared to remains of terrestrial dinosaurs, and even some aquatic animals strongly supports Spinosaurus being an aquatic animal spending much of its life in water where its teeth were shed and preserved.
Remains of enigmatic spinosaurs from mid-Cretaceous North African strata have, for over a century, been the subject of taxonomic deliberations. The gigantic Spinosaurus aegyptiacus Stromer, 1915 has gained iconic status in the vertebrate palaeontological community and amongst the general public. Perhaps the largest predatory dinosaur to have lived, this animal exhibits a bizarre range of adaptations consistent with a piscivorous diet and semiaquatic mode of life. Despite its popularity, the systematics of this taxon remains a matter of considerable debate. African spinosaur taxonomy is complex, with up to three separate species proposed for the Cretaceous Kem Kem Group of Morocco: Spinosaurus aegyptiacus, Spinosaurus maroccanus Russell, 1996 and Sigilmassasaurus brevicollis Russell, 1996.
Here, the taxonomic status of spinosaurs in the Kem Kem Group is examined, and the morphology of the cervical and dorsal vertebrae re-evaluated in the light of this taxonomic reappraisal.
The validity of Spinosaurus maroccanus and Sigilmassasaurus brevicollis are not supported, as all autapomorphies of these taxa are proposed here to be the result of intraspecific variation, or morphological changes through the axial column of a single taxon. Both taxa are junior synonyms of Spinosaurus aegyptiacus.
This reanalysis has implications for the taxonomy of spinosaurs from other deposits. Based on the currently available material, the Brazilian spinosaurid Oxalaia quilombensis is determined to fall within the Spinosaurus aegyptiacus hypodigm. The prevalence of spinosaurid heterodonty and limited diagnostic potential of spinosaur teeth necessitates that two spinosaurid tooth taxa: Ostafrikasaurus crassiserratus and Siamosaurus suteethorni, be regarded nomina dubia.
Isolated cervical vertebrae from the mid Cretaceous Kem Kem beds of south east Morocco are referred to the theropod dinosaur clade Abelisauroidea, and represent the first axial remains from this deposit referred to this group. An isolated axis is referred to Abelisauroidea on account of the invaginated spinopostzygapophyseal lamina; the extremely large, projecting and pointed epipophyses; and the anteroposteriorly long, transversely compressed neural spine with a gently convex and unexpanded dorsal margin. In addition, postzygapophyseal facets which completely overhang the centrum posteriorly and lack lateral orientation indicate abelisaurid affinities. An anterior cervical (C4?) is referred to Noasauridae based on an anteriorly-positioned, reduced neural spine and extremely well developed centroprezygapophyseal fossae. This specimen represents both the smallest dinosaur and the first definitive small-bodied dinosaur from the Kem Kem beds. The affinities of the new material are discussed in the context of other abelisauroid remains reported from the Kem Kem assemblage and elsewhere in Africa.
Ornithocheirus wiedenrothi, from the Hauterivian (Early Cretaceous of Germany), is a taxon represented by three-dimensional remains of the lower jaw and wing elements. Its phylogenetic affinities have for long been elusive, though several works had already pointed out that it probably did not belong within the wastebasket genus Ornithocheirus. In the present contribution, we redescribe this species, assigning it to the new genus Targaryendraco and offering updated morphological comparisons. Subsequently, we present a phylogenetic analysis in which we recover a clade formed by Targaryendraco, Aussiedraco, Barbosania, Aetodactylus, Camposipterus and Cimoliopterus. This newly recognised clade is interesting in being quite cosmopolitan and spanning from the Hauterivian to the Cenomanian, like its sister-group, the Anhangueria. The recognition of this clade helps fill the temporal gap between the Anhangueria and Cimoliopterus, and also demonstrates that the diversity of Cretaceous toothed pterosaurs was higher than previously thought.
A series of pterosaur bones from the Upper Cretaceous (Campanian) of Velaux (Bouches-du-Rhône, southeastern France) is described. This material, including both cranial and postcranial elements found in close association and likely belonging to a single immature individual, is assigned to a new genus and species of azhdarchid pterosaur, Mistralazhdarcho maggii. This large-sized taxon (wingspan ca. 4.5 m in the holotype, possibly reaching 5–6 m in mature individuals) is characterized by a slightly downturned mandibular symphysis that shows a ‘V’-shaped cross-sectional profile and bears a well-developed, anteriorly located median eminence on its dorsal surface. The presence of a median eminence suggests that Mistralazhdarcho might be closely related to Alanqa from the Cenomanian of Morocco. The material described here represents the first partial skeleton of a pterosaur recovered from the Late Cretaceous deposits of western Europe, and the new taxon is one of the most completely known European azhdarchids. Mistralazhdarcho is intermediate in size between the medium-sized genus Eurazhdarcho and the giant-sized genus Hatzegopteryx, two azhdarchids from the Maastrichtian of Romania. The discovery of Mistralazhdarcho suggests the presence of a third azhdarchid size class in the continental ecosystems of the latest Cretaceous European archipelago.
http://www.zoobank.org/urn:lsid:zoobank.org:pub:00DEB0A5-6B18-42A4-A4BF-79EC9EEF0230
Citation for this article: Vullo, R., G. Garcia, P. Godefroit, A. Cincotta, and X. Valentin. 2018. Mistralazhdarcho maggii, gen. et sp. nov., a new azhdarchid pterosaur from the Upper Cretaceous of southeastern France. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2018.1502670.
Background
Anhanguerids comprise an important clade of pterosaurs, mostly known from dozens of three-dimensionally preserved specimens recovered from the Lower Cretaceous Romualdo Formation (northeastern Brazil). They are remarkably diverse in this sedimentary unit, with eight named species, six of them belonging to the genus Anhanguera. However, such diversity is likely overestimated, as these species have been historically diagnosed based on subtle differences, mainly based on the shape and position of the cranial crest. In spite of that, recently discovered pterosaur taxa represented by large numbers of individuals, including juveniles and adults, as well as presumed males and females, have crests of sizes and shapes that are either ontogenetically variable or sexually dimorphic.
Methods
We describe in detail the skull of one of the most complete specimens referred to Anhanguera, AMNH 22555, and use it as a case study to review the diversity of anhanguerids from the Romualdo Formation. In order to accomplish that, a geometric morphometric analysis was performed to assess size-dependent characters with respect to the premaxillary crest in the 12 most complete skulls bearing crests that are referred in, or related to, this clade, almost all of them analyzed first hand.
Results
Geometric morphometric regression of shape on centroid size was highly statistically significant (p = 0.0091) and showed that allometry accounts for 25.7% of total shape variation between skulls of different centroid sizes. Premaxillary crests are both taller and anteroposteriorly longer in larger skulls, a feature consistent with ontogenetic growth. A new diagnosis is proposed for Anhanguera, including traits that are nowadays known to be widespread within the genus, as well as ontogenetic changes. AMNH 22555 cannot be referred to “Anhanguera santanae” and, in fact, “Anhanguera santanae”, “Anhanguera araripensis”, and “Anhanguera robustus” are here considered nomina dubia.
Discussion
Historically, minor differences in crest morphology have been used in the definition of new anhanguerid species. Nowadays, this practice resulted in a considerable difficulty in referring well-preserved skulls into known taxa. When several specimens are analyzed, morphologies previously believed to be disparate are, in fact, separated by a continuum, and are thus better explained as individual or temporal variations. Stratigraphically controlled excavations on the Romualdo Formation have showed evidence for faunal turnover regarding fish communities. It is thus possible that some of the pterosaurs from this unit were not coeval, and might even represent anagenetic morphotypes. Unfortunately, amateur collecting of Romualdo Formation fossils, aimed especially at commerce, resulted in the lack of stratigraphic data of virtually all its pterosaurs and precludes testing of these further hypotheses.
A three-dimensional and almost complete pterosaur mandible from the Crato Formation (Early Cretaceous of Northeastern Brazil), Araripe Basin, is described as a new species of a tapejarine tapejarid. Tapejarines are a particular group of toothless pterosaurs, characterized by well-developed cranial crests, downturned rostra, and have been proposed to represent frugivorous flying reptiles. Though comparatively well represented and distributed, the evolutionary history of the group is still poorly known, and the internal relationships of its members are not well understood. The new species here reported, named Aymberedactylus cearensis gen. et sp. nov., adds new data concerning the evolution of the group, concerning their morphology and geographical origin. It differs from known tapejarids due to its unusually elongate retroarticular process and a shallow fossa on the splenial exhibiting distinctive rugose texture. Furthermore, it exhibits a suite of basal and derived conditions within the Tapejaridae, demonstrating how their morphological traits probably evolved and that these forms were even more diverse than already acknowledged. The discovery of Aymberedactylus cearensis sheds new light on the evolutionary history of the Tapejarinae.
A short section of a mandibular symphysis is the first cranial fossil of a pterosaur to be reported from the Upper Jurassic of Tendaguru, Tanzania. It is made the holotype of a new dsungaripteroid pterosaur, Tendaguripterus recki n. gen. n. sp. All previously named pterosaur taxa from Tendaguru are shown to be nomina dubia. The pterosaur assemblage from Tendaguru contains a "rhamphorhynchoid", as well as the dsungaripteroid, and is similar in its systematic composition to other Late Jurassic pterosaur assemblages from Laurasia. The diversity and broad distribution of dsungaripteroids in the Late Jurassic suggests that the group was already well established by this time.
Der erste Schädelrest eines Flugsauriers aus dem Oberjura von Tendaguru in Tansania wird beschrieben. Bei dem Fundstück handelt es sich um ein bezahntes Unterkieferbruchstück aus der Symphysenregion. Der Fund gehört zu einem neuen Taxon, das als Tendaguripterus recki n. gen. n. sp. bezeichnet und zur Überfamilie Dsungaripteroidea gestellt wird. Alle zuvor aus den Tendaguru-Schichten beschriebenen Taxa werden als nomina dubia angesehen. In Tendaguru sind Verteter der „Rhamphorhynchoidea“ und Dsungaripteroidea nachgewiesen. Diese systematische Zusammensetzung ist derjenigen anderer Flugsaurier-Vergesellschaftungen der späten Jura-Zeit ähnlich. Die Vielfalt und die weite Verbreitung der Dsungaripteroidea in Laurasia läßt darauf schließen, daß sich diese Flugsauriergruppe bereits in der späten Jura-Zeit erfolgreich durchgesetzt hatte.
doi:10.1002/mmng.1999.4860020109
A well preserved middle caudal vertebra from middle Cretaceous (?Albian–lower Cenomanian) deposits informally known as the “Kem Kem beds” exposed in the Gara Sbaa region of Morocco is attributed to a large-bodied titanosaurian sauropod dinosaur. It represents one of the best-preserved and most complete skeletal elements reported for this sauropod group from the Kem Kem sequence. The vertebra is generally similar to middle caudals of the lithostrotian titanosaur Baurutitan britoi from the Upper Cretaceous Bauru Group of Brazil, but differs in several respects, such as: (1) a transversely compressed (as opposed to more square in posterior view) centrum; (2) a taller, anteroposteriorly longer, and more anteriorly positioned neural spine; and (3) prezygapophyses that are subtriangular in lateral view. It represents an animal that likely attained a very large body size (possibly over 25 m in total length), considerably larger than the diplodocoid Rebbachisaurus garasbae, the only named sauropod from the Kem Kem assemblage. Additional, selected specimens from the Kem Kem beds are described, with some probably referable to Titanosauria. In the Kem Kem sequence, sauropod fossils are far less common than those of predatory dinosaurs, which include several coeval, multi-ton taxa. This was likely due to an abundance of potential aquatic prey as well as complex niche partitioning among sympatric theropods, pterosaurs, and crocodyliforms. Nevertheless, some predators, such as the giant theropod Carcharodontosaurus saharicus, likely preyed on sauropods. The taxon represented by the new vertebra (and possibly other isolated remains from the Kem Kem region) and the giant Egyptian titanosaurian Paralititan stromeri rank among the largest known sauropods. Most other North African Cretaceous sauropods appear to have reached only modest adult body sizes; this could, however, be an artifact of the limited number of fossils and uncertainty in the ontogenetic stages represented by most specimens. The morphology of the Kem Kem vertebra suggests that the taxon it represents may have been more closely related to South American and/or European titanosaurians than to other members of this clade from sub-Saharan Africa.
We describe the partially preserved femur of a large-bodied theropod dinosaur from the Cenomanian “Kem Kem Compound Assemblage” (KKCA) of Morocco. The fossil is housed in the Museo Geologico e Paleontologico “Gaetano Giorgio Gemmellaro” in Palermo (Italy). The specimen is compared with the theropod fossil record from the KKCA and coeval assemblages from North Africa. The combination of a distally reclined head, a not prominent trochanteric shelf, distally placed lesser trochanter of stout, alariform shape, a stocky shaft with the fourth trochanter placed proximally, and rugose muscular insertion areas in the specimen distinguishes it from Carcharodontosaurus, Deltadromeus and Spinosaurus and supports referral to an abelisaurid. The estimated body size for the individual from which this femur was derived is comparable to Carnotaurus and Ekrixinatosaurus (up to 9 meters in length and 2 tons in body mass). This find confirms that abelisaurids had reached their largest body size in the “middle Cretaceous,” and that large abelisaurids coexisted with other giant theropods in Africa. We review the taxonomic status of the theropods from the Cenomanian of North Africa, and provisionally restrict the Linnean binomina Carcharodontosaurus iguidensis and Spinosaurus aegyptiacus to the type specimens. Based on comparisons among the theropod records from the Aptian-Cenomanian of South America and Africa, a partial explanation for the so-called “Stromer’s riddle” (namely, the coexistence of many large predatory dinosaurs in the “middle Cretaceous” record from North Africa) is offered in term of taphonomic artifacts among lineage records that were ecologically and environmentally non-overlapping. Although morphofunctional and stratigraphic evidence supports an ecological segregation between spinosaurids and the other lineages, the co-occurrence of abelisaurids and carcharodontosaurids, two groups showing several craniodental convergences that suggest direct resource competition, remains to be explained.
Although pterosaurs from Africa are still rare, in recent years several specimens have been described from the Kem Kem beds (Upper Cretaceous, Cenomanian) of Morocco. Here we describe four additional specimens from this informal lithostratigraphic unit: a jaw fragment, two mid-cervical vertebrae, and a humerus. All these specimens show three-dimensional preservation, differing much from the flat condition found in most pterosaur material. The vertebrae are particularly well preserved, and allow accurate observations on the pneumatization of the neural arch. Based on comparable material, we show that at least two edentulous pterosaur species were present in this informal lithostratigraphic unit, thus adding to the growing evidence of considerable pterosaur diversity in northwestern Africa during the "middle" Cretaceous. So far, the Kem Kem beds have the most diverse pterosaur fauna in this continent, with the presence of anhanguerids, azhdarchids, pteranodontids, and tapejarids.
New remains of an azhdarchid pterosaur were discovered from the Upper Cretaceous (Santonian) Csehbánya Formation at the Iharkút vertebrate locality in the Bakony Mountains, western Hungary. Among the isolated bones, consisting principally of 21 symphyseal jaw fragments, four cervical vertebrae, a right radius, and some fragmentary limb bones, is a complete articulated mandible that represents one of the best-preserved mandibular material of any presently known azhdarchid pterosaur. The complete edentulous jaw, referred to Bakonydraco galaczi gen. et sp. nov. posesses several features diagnostic for azhdarchids which prove that Bakonydraco belongs to this group. The cervical vertebrae exhibit azhdarchid features and consequently are referred to as Azhdarchidae indet. The discovery of these fossils helps to understand the construction of the azhdarchid mandible and provides new insight for studying the feeding style of the edentulous azhdarchid pterosaurs.
The pterosaur fossil record from Africa is exceedingly scarce and one of the least known for any continental land mass. The specimens here described are housed at the Naturkundemuseum of the Humboldt University and consist of two cervical vertebrae, a coracoid and a wing metacarpal recovered from the Upper Jurassic Tendaguru Formation, Tanzania. Due to the general morphology and the absence of a lateral pneumatic foramen in both vertebrae, as well as the presence of a longitudinal depression, not previously reported in pterosaurs, we consider these specimens as representatives of a new species of Azhdarchidae. Moreover, because the coracoid, which bears three well-developed pneumatic foramina, has a well-excavated depression that is medially positioned at the posterior face of the acrocoracoid process, we regard this as a new basal pterodactyloid species. The wing metacarpal is greatly elongated and clearly belongs to Pterodactyloidea. Its elongation and slender aspect, as well as the sub-triangular shape of its proximal articular end, likely place it within the Tapejaroidea. The material here described shows the potential of these deposits to provide more informative pterosaur material and provisionally extends the oldest record of azhdarchids to the Kimmeridgian–Tithonian of Africa.
Diverse crocodyliforms have been discovered in recent years in Cretaceous rocks on southern landmasses formerly composing Gondwana. We report here on six species from the Sahara with an array of trophic adaptations that significantly deepen our current understanding of African crocodyliform diversity during the Cretaceous period. We describe two of these species (Anatosuchus minor, Araripesuchus wegeneri) from nearly complete skulls and partial articulated skeletons from the Lower Cretaceous Elrhaz Formation (Aptian-Albian) of Niger. The remaining four species (Araripesuchus rattoides sp. n., Kaprosuchus saharicus gen. n. sp. n., Laganosuchus thaumastos gen. n. sp. n., Laganosuchus maghrebensis gen. n. sp. n.) come from contemporaneous Upper Cretaceous formations (Cenomanian) in Niger and Morocco.
Titanosauriform sauropod dinosaurs are widely regarded as the most diverse and abundant large herbivores in Cretaceous paleoecosystems of Gondwanan landmasses. Nevertheless, remains of these animals are scarce in Late Cretaceous deposits of continental Africa and the then-conjoined Arabian Peninsula. Here we describe two new titanosauriform fossils from the lower Upper Cretaceous (Cenomanian) ‘Kem Kem beds’ of Morocco that improve our understanding of the morphology and paleoecology of Afro-Arabian members of this clade. One specimen is a nearly complete, well-preserved anterior dorsal vertebra that pertains to a large-bodied member of Somphospondyli, possibly to a basal titanosaurian. The second specimen is a partial ischium that is not identifiable beyond Somphospondyli; nevertheless, the element is significant in exhibiting numerous tooth marks that we attribute to a very large carnivorous dinosaur, probably a carcharodontosaurid or Spinosaurus. These feeding traces constitute direct evidence that sauropods were a food source for at least one African Late Cretaceous theropod. It is presently uncertain whether or not the new titanosauriform elements pertain to any of three named genera from the early Late Cretaceous of Africa (Aegyptosaurus, Paralititan, and Angolatitan), or whether they represent previously undescribed taxa.
We describe adaptations for a semiaquatic lifestyle in the dinosaur Spinosaurus aegyptiacus. These adaptations include retraction of the fleshy nostrils to a position near the mid-region of the skull and an elongate
neck and trunk that shift the center of body mass anterior to the knee joint. Unlike terrestrial theropods, the pelvic girdle
is downsized, the hindlimbs are short, and all of the limb bones are solid without an open medullary cavity, for buoyancy
control in water. The short, robust femur with hypertrophied flexor attachment and the low, flat-bottomed pedal claws are
consistent with aquatic foot-propelled locomotion. Surface striations and bone microstructure suggest that the dorsal “sail”
may have been enveloped in skin that functioned primarily for display on land and in water.
A pterosaur bone bed with at least 47 individuals (wing spans: 0.65-2.35 m) of a new species is reported from southern Brazil from an interdunal lake deposit of a Cretaceous desert, shedding new light on several biological aspects of those flying reptiles. The material represents a new pterosaur, Caiuajara dobruskii gen. et sp. nov., that is the southermost occurrence of the edentulous clade Tapejaridae (Tapejarinae, Pterodactyloidea) recovered so far. Caiuajara dobruskii differs from all other members of this clade in several cranial features, including the presence of a ventral sagittal bony expansion projected inside the nasoantorbital fenestra, which is formed by the premaxillae; and features of the lower jaw, like a marked rounded depression in the occlusal concavity of the dentary. Ontogenetic variation of Caiuajara dobruskii is mainly reflected in the size and inclination of the premaxillary crest, changing from small and inclined (∼115°) in juveniles to large and steep (∼90°) in adults. No particular ontogenetic features are observed in postcranial elements. The available information suggests that this species was gregarious, living in colonies, and most likely precocial, being able to fly at a very young age, which might have been a general trend for at least derived pterosaurs.
Citation: Averianov A (2014) Review of taxonomy, geographic distribution, and paleoenvironments of Azhdarchidae (Pterosauria) ZooKeys 432: 1–107. doi: 10.3897/zookeys.432.7913 Abstract The taxonomy, geographic distribution, and paleoenvironmental context of azhdarchid pterosaurs are reviewed. All purported pteranodontid, tapejarid, and azhdarchid specimens from the Cenomanian Kem Kem beds of Morocco are referred to a single azhdarchid taxon, Alanqa saharica. The four proposed autapomorphies of Eurazhdarcho langendorfensis from the lower Maastrichtian Sebeş Formation of Ro-mania are based on misinterpretations of material and this taxon is likely a subjective junior synonym of Hatzegopteryx thambema. Among 54 currently reported azhdarchid occurrences (51 skeletal remains and 3 tracks) 13% are from lacustrine deposits, 17% from fluvial plain deposits, 17% from coastal plain depos-its, 18% from estuarine and lagoonal deposits, and 35% from costal marine deposits. Azhdarchids likely inhabited a variety of environments, but were abundant near large lakes and rivers and most common in nearshore marine paleoenvironments. Copyright Alexander Averianov. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. A peer-reviewed open-access journal
Numerous taxa make up the Early Cretaceous fauna of Brazil, including Ornithocheiroidea, Tapejaridae,
Thalassodromidae, Chaoyangopteridae and a purported member of Azhdarchidae. Dsungaripteridae has only been tentatively assumed to be present in the form of ‘Santanadactylus’ spixi. New study of NMSG SAO 251093 (a specimen referred to Thalassodromeus sethi) suggests it is a previously unknown species of dsungaripterid, Banguela oberlii, tax. nov., differing from Thalassodromeus and other pterosaurs from the Early Cretaceous of Brazil by a unique combination of characters, including an upturned jaw tip, a short dorsal mandibular symphyseal shelf (dmss), and an autapomorphic thin crest placed halfway along the fused mandibular symphysis without a keel along the ventral margin of the jaw. B. oberlii, tax. nov., is referred to Dsungaripteridae based on a dmss no longer than the ventral shelf, U-shaped caudal margin of the ventral shelf and lateral margins of the mandibular symphysis concave in dorsal view. B. oberlii, tax. nov., is the youngest known dsungaripterid, and expands known morphological diversity in the clade as well as the Early Cretaceous pterosaur fauna of South America.
The pterosaurs were a diverse group of Mesozoic flying reptiles that underwent a body plan reorganization, adaptive radiation, and replacement of earlier forms midway through their long history, resulting in the origin of the Pterodactyloidea, a highly specialized clade containing the largest flying organisms. The sudden appearance and large suite of morphological features of this group were suggested to be the result of it originating in terrestrial environments, where the pterosaur fossil record has traditionally been poor [1, 2], and its many features suggested to be adaptations to those environments [1, 2]. However, little evidence has been available to test this hypothesis, and it has not been supported by previous phylogenies or early pterodactyloid discoveries. We report here the earliest pterosaur with the diagnostic elongate metacarpus of the Pterodactyloidea, Kryptodrakon progenitor, gen. et sp. nov., from the terrestrial Middle-Upper Jurassic boundary of Northwest China. Phylogenetic analysis confirms this species as the basalmost pterodactyloid and reconstructs a terrestrial origin and a predominantly terrestrial history for the Pterodactyloidea. Phylogenetic comparative methods support this reconstruction by means of a significant correlation between wing shape and environment also found in modern flying vertebrates, indicating that pterosaurs lived in or were at least adapted to the environments in which they were preserved.
We describe an extensive ichnofossil assemblage from the likely Cenomanian-age 'lower' and 'upper' units of the 'Kem Kem beds' in southeastern Morocco. In the lower unit, trace fossils include narrow vertical burrows in cross-bedded sandstones and borings in dinosaur bone, with the latter identified as the insect ichnotaxon Cubiculum ornatus. In the upper unit, several horizons preserve abundant footprints from theropod dinosaurs. Sauropod and ornithischian footprints are much rarer, similar to the record for fossil bone and teeth in the Kem Kem assemblage. The upper unit also preserves a variety of invertebrate traces including Conichnus (the resting trace of a sea-anemone), Scolicia (a gastropod trace), Beaconites (a probable annelid burrow), and subvertical burrows likely created by crabs for residence and detrital feeding on a tidal flat. The ichnofossil assemblage from the Upper Cretaceous Kem Kem beds contributes evidence for a transition from predominantly terrestrial to marine deposition. Body fossil and ichnofossil records together provide a detailed view of faunal diversity and local conditions within a fluvial and deltaic depositional setting on the northwestern coast of Africa toward the end of the Cretaceous.
Thirty-seven well-preserved, isolated theropod teeth from the Early Cenomanian Kem Kem beds, Morocco, are identified by using morphometric data and direct comparison with teeth previously described in the literature. Direct comparison reveals that four different morphotypes (MT 1–4) are present in the sample. The teeth of MT 1 are characterised by unserrated carinae and belong to spinosaurid dinosaurs. The teeth of MT 2–4 have serrated carinae, and our data analysis indicates they are of carcharodontosaurid, dromaeosaurid, and abelisaurid origin. Three types of crown enamel ornamentation are present among the teeth of MT 1, which implies that, apart from Spinosaurus
aegyptiacus STROMER 1915, more than one species of spinosaurine theropods may be present in the Early Cenomanian of Northern Africa. Our results also confirm the occurrence of abelisaurids, dromaeosaurids, and carcharodontosaurids in Morocco.
In this study, we erect Sauroniops pachytholus gen. et sp. nov., a large-bodied theropod dinosaur from the Cenomanian (Upper Cretaceous) of Morocco, on the basis of an almost complete frontal showing a unique combination of features including a naso-frontal suture extended along 40% of the frontal length, a thick dome in the anterolateral corner of the dorsal surface, a trapezoidal prefrontal facet that is restricted to the anterodorsal margin of the lateral surface of the frontal with no participation in the orbital roof and separated from the lacrimal facet by a narrow vertical lamina, a hypertrophied 'D-shaped' lacrimal facet that is four times the anterior depth of the postorbital facet, and a raised posteromedial margin of the dorsal surface describing a saddle with the anterolateral dome and confluent with a series of anteromedial rugosities. Phylogenetic analysis found robust support for placing Sauroniops among the basal carcharodontosaurids and related to Eocarcharia, showed that some of the unusual features of the new theropod were convergently acquired by abelisaurids, and revealed a mosaic pattern in the evolution of the carcharodontosaurid skull table. The frontals of Sauroniops and Carcharodontosaurus, both from the 'Kern Kern compound assemblage' of Morocco, show comparable size but differ in the extent of the naso-frontal articulation, the shape and disposition of the prefrontal and lacrimal articulations, the development of dorsal ornamentation and the morphology of the supratemporal fossa. Among carcharodontosaurids, the skull table developed unique configurations among each lineage and appears diagnostic at the species-level. The dome-like frontal in Sauroniops may indicate head-butting behaviour in this taxon or evolved for visual display.
5 ABSTRACT: We report the occurrence of an isolated avian dorsal vertebra in Cretaceous strata of Morocco. The specimen was found near Erfoud oasis in the Tafilalt region of southeastern Morocco preserved in a reddish sandstone. It has a large neural canal (ratio height neural canal/cranial articulation surface = 0.67), a feature regarded as a synapomorphy of Aves. Compared to dorsal vertebrae of other Mesozoic birds, the Moroccan specimen is most similar to Rahona ostromi from the Late Cretaceous of Madagascar. The absence of a developed pleurocoel, however, indicates that it belongs to a distinct taxon. Although the correct phylogenetic position of this specimen within Aves cannot be reliably determined, it most likely represents a basal group. This specimen is significant because it represents the second osteological evidence of a Cretaceous bird from northern Gondwana.
Fossil snakes are relatively well represented in the Upper Cretaceous of northern Africa, with material known from Morocco, Sudan, Egypt, Libya, Algeria, and Niger. The Moroccan Kem Kem beds yield a particularly diverse snake assemblage, with Simoliophiidae, Madtsoiidae, ?Nigerophiidae and several unnamed taxa co-occurring. These fossils are important for our understanding of the early evolutionary history of snakes, and may shed light on the ecology and initial diversification of basal snakes. We describe a new taxon, Norisophis begaa gen. et sp. nov., from the Kem Kem beds of Begaa, in southeast Morocco. It is characterised by a marked interzygapophyseal constriction, parazygantral foramina, an incipient prezygapophyseal process, and an anterio-posteriorly short centrum. Several characteristics shared with Najash, Seismophis, Madtsoiidae, and Coniophis suggest that Norisophis is a stem ophidian. N. begaa further increases the diversity and disparity of snakes within the Kem Kem beds, supporting the hypothesis that Africa was a mid-Cretaceous hotspot for snakes.
Pterosaurs, a Mesozoic group of flying archosaurs, have become a focal point for debates pertaining to the impact of sampling biases on our reading of the fossil record, as well as the utility of sampling proxies in palaeo-diversity reconstructions. The completeness of the pterosaur fossil specimens themselves potentially provides additional information that is not captured in existing sampling proxies, and might shed new light on the group's evolutionary history. Here we assess the quality of the pterosaur fossil record via a character completeness metric based on the number of phylogenetic characters that can be scored for all known skeletons of 172 valid species, with averaged completeness values calculated for each geological stage. The fossil record of pterosaurs is observed to be strongly influenced by the occurrence and distribution of Lagerstätten. Peaks in completeness correlate with Lagerstätten deposits, and a recovered correlation between completeness and observed diversity is rendered non-significant when Lagerstätten species are excluded. Intervals previously regarded as potential extinction events are shown to lack Lagerstätten and exhibit low completeness values: as such, the apparent low diversity in these intervals might be at least partly the result of poor fossil record quality. A positive correlation between temporal patterns in completeness of Cretaceous pterosaurs and birds further demonstrates the prominent role that Lagerstätten deposits have on the preservation of smaller bodied organisms, contrasting with a lack of correlation with the completeness of large-bodied sauropodomorphs. However, we unexpectedly find a strong correlation between sauropodomorph and pterosaur completeness within the Triassic-Jurassic, but not the Cretaceous, potentially relating to a shared shift in environmental preference and thus preservation style through time. This study highlights the importance of understanding the relationship between various taphonomic controls when correcting for sampling bias, and provides additional evidence for the prominent role of sampling on observed patterns in pterosaur macroevolution.
The skeletal proportions and size distribution of the Late Cretaceous pterosaur Pteranodon are described. The functional morphology of flight is discussed and it is argued that the patagium attached to the femora which enabled the hindlimb to assist in flapping and control of the patagium. Movements of the wing provided yaw control so that the skull and cranial crest need not be interpreted as a forward rudder. Terrestrial locomotion is discussed, and it is argued that Pteranodon and other large pterodactyloids must have been bipedal. The functional morphology of the jaws and feeding are discussed, and it is argued that Pteranodon could swim and fed while swimming on the water rather than dipping food while in flight. The function of postcranial pneumaticity is also discussed.
The 'Gres rouges infracenomaniens' of southern Morocco, possibly of Albian age, contain evidence of one of the most diversified dinosaur assemblages known from Africa, including a relatively long-necked species of Spinosaurus and abundant but isolated bones of a peculiar theropod ('Spinosaurus B' of Stromer 1934). Also preserved are the oldest records of abelisaurids and among the oldest records of titanosaurids in Africa. Bones of infantile didnosaurs are present. The assemblage resembles that of the Bahariya Formation more than that of Gadoufaoua, possibly because of a trophic dependence upon large, freshwater fishes. It was more closely linked zoogeographically to South America than to North America.
Pterosaurs first appeared in the Late Triassic and persisted until the terminal Cretaceous: they achieved a global distribution during the Mesozoic. Here, we attempt to provide the first comprehensive summary of pterosaur distribution through time and space, including information on the taxonomie composition of pterosaur faunas and the lithostratigraphic units in which they occur. We hope that this compilation will be used as a primary research tool, permitting more detailed and rigorous analyses of pterosaur diversity and palaeobiogeography than have been possible to date.
Fragmentary cranial bones of dinosaur origin have been recently recovered from the Kern Kern beds (Upper Cretaceous, Cenomanian) of Morocco. They include two incompletely preserved maxillary bones evidencing diagnostic features of abelisaurid theropods. These new finds provide further evidence of Abelisauridae in the Late Cretaceous of Morocco.
Numerous remains of the azhdarchid pterosaur Quetzalcoatlus sp., have been recovered over the last twenty years from the Late Cretaceous (Maastrichtian) rocks in Big Bend National Park in Trans-Pecos Texas. Among more than 200 bones found at one locality are four incomplete skulls and mandibles, which provide the most complete information about cranial structures in the Azhdarchidae. What is currently known indicates that the Azhdarchidae is the sister group of the Tapejaridae from Early Cretaceous deposits in northeastern Brazil.
New material of dsungaripterid pterosaurs from the Early Cretaceous of Tatal, western Mongolia, allows the diagnoses of Dsungaripteridae and Noripterus to be amended. All pterosaurs found at Tatal belong to Dsungaripteridae (either Dsungaripterus or Noripterus). The name Phobetor is a junior synonym of Noripterus. The differing shapes of the anterior tips of skulls, differing tooth morphologies and the coexistence of both Dsungaripterus and Noripterus may imply that they occupied distinct ecological niches.
Remains of pterosaurs, the dominant aerial vertebrate throughout much of the Mesozoic were, until relatively recently, almost exclusively known from marine and marginal marine sediments of western Europe and North America. Prior to the 1960s Mesozoic deposits in the former Soviet Union and Mongolia had produced very few pterosaurs, but, in the last thirty years, many remains, including some from continental environments, have been found. Most important among these are Sordes and Batrachognathus from the Late Jurassic of Karatau in Kazakhstan, Azhdarcho from the Late Cretaceous of the Kyzylkum desert in Uzbekistan, and a number of new Mongolian pterosaurs, including a possible anurognathid from the Mid Jurassic of Bakhar, a dsungaripterid from the early Early Cretaceous of Tatal and an ornithocheirid from the late Early Cretaceous of Khuren‐Dukh. Although already documented to some extent, the significance of these discoveries remains underappreciated.The discovery and collection of these pterosaurs is described and the bearing of some of the more important material on current problems of pterosaur biology is discussed. We confirm Sharov's observation that the hind limbs of Sordes form an integral part of the flight apparatus, attached externally to the cheiropatagium and internally to the uropatagium, which is supported and manipulated by the fifth toe. The former Soviet and Mongolian pterosaurs also help to fill a number of important morphological and temporal gaps in the pterosaur fossil record and provide the best available evidence of pterosaurs from continental environments. With the exception of insectivores, these and other continental pterosaurs appear to have pursued lifestyles similar to those of their marine counterparts, leading us to suspect that pterosaurs largely failed to exploit terrestrial habitats.
The assignment of a fragment of the anterior tip of a pterosaur rostrum from the Cenomanian Cambridge Greensand of eastern England to the ornithocheirid Coloborhynchus capito (Seeley, 1870) is confirmed. The fragment represents partial left and right fused premaxillae and retains broken teeth within alveoli. A width across the palate of 57.4 mm, a height at the anterior rostrum in excess of 95 mm and a tooth with a diameter of 13 mm at the base of the crown indicates a remarkably large individual, tentatively estimated to have had a skull length in excess of 0.75 m and a wing span of up to 7 m. This fragment represents the largest toothed pterosaur yet reported. This find, and several other large postcranial fragments from the Cambridge Greensand, suggest that ornithocheirids, toothed ornithocheiroids known from the earliest Early to early Late Cretaceous (Valanginian–Cenomanian) achieved very large, but not giant size. Pteranodontids, edentulous ornithocheiroids currently known only from the mid Upper Cretaceous (Coniacian–early Campanian), reached similar dimensions, up to 7.25 m in wing span. Contrary to popular myth, however, ornithocheiroids did not attain the giant sizes (wing spans of 10 m or more) achieved by azhdarchids in the late Late Cretaceous (Campanian–Maastrichtian).