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Notice on some new types of organic remains from the Coal-Measures of Illinois
... не менее, до сих пор это предположение не было подтверждено ископаемыми находками. Здесь задокументировано скопление семи Euproops danae (Meek et Worthen, 1865), сохранившихся на той же поверхности напластования алевролита группы Фаррингтон пенсильванского возраста. Эти экземпляры проявляют потенциальную репродуктивную стратегию Belinuridae, которая сравнима с таковой рецентных форм. ...
... However, no body fossil evidence has been presented to support this idea. Here, we document a cluster of seven Euproops danae (Meek et Worthen, 1865) specimens preserved on the same bedding plane of Pennsylvanian-aged Farrington Group siltstone. These specimens record potential reproductive strategies of belinurids that are comparable to extant counterparts. ...
... The only records of multiple fossil horseshoe crab specimens preserved on a same bedding plane are Ambrose & Romano [1972] and unfigured discussions in Fisher [1979]. Here, we reconsider the Ambrose & Romano [1972] slab that preserves specimens of the belinurid Euproops danae (Meek et Worthen, 1865) and, in doing so, discuss the first record of a fossil horseshoe crab cluster. ...
Xiphosurids are archetypal marine arthropods that have received considerable research interest from both biologists and palaeontologists. Mating clusters of extant horseshoe crabs have informed research on clustering in other fossil arthropods, such
as trilobites. Furthermore, the evolutionary stasis exhibited
by horseshoe crabs suggests that fossil xiphosurids may also have mated in clusters. However, no body fossil evidence has been presented to support this idea. Here, we document a cluster of seven Euproops danae (Meek et Worthen, 1865) specimens preserved on the same bedding plane of Pennsylvanian-aged Farrington Group siltstone. These specimens record potential
reproductive strategies of belinurids that are comparable to extant counterparts. This gregarious behaviour may have decreased the impact of predation and/or contributed to genetic diversity. The cluster ultimately highlights a further example of xiphosurid evolutionary stasis.
... Class XIPHOSURA Latreille, 1802 Order XIPHOSURIDA Latreille, 1802 Suborder LIMULINA Richter & Richter, 1929 Infraorder LIMULICINA Richter & Richter, 1929 Superfamily EUPROOPOIDEA Eller, 1938 Family EUPROOPIDAE Eller, 1938 Genus EUPROOPS Meek, 1867 Type species Euproops danae (Meek & Worthen, 1865). ...
... Euproops danae (Meek & Worthen, 1865) Raymond (1944) described the species with reference to two specimens in the collection of the Museum of Comparative Zoology, Harvard, Cambridge, USA MCZ4673 (refd. Raymond, 1944, p. 486), MCZ4686 (refd. ...
... The telson articulates within the median arch of the posterior margin of the opisthosoma, A strong carinate ridge runs the full length of the telson. Fisher (1975b) synonymized all the species attributed to the genus Euproops from the Mazon Creek locality with the type species , Euproops danae (Meek & Worthen, 1865) in an unpublished PhD thesis . The characters used by Fisher, based on an understanding of the taphonomic processes affecting xiphosuran fossils, are valid in my opinion . ...
Euproops kilmersdonensis Ambrose & Romano, 1972 is proposed as a synonym of Euproops danae (Meek & Worthen, 1865) from Mazon Creek, Illinois. Five other species attributed to Euproops Meek, 1867 and one species attributed to Prestwichianella nitida Dix & Pringle, 1929, from the Westphalian D of the South Wales Coalfield, described by Dix & Pringle (1929, 1930) are also synonymized with E. danae. In addition, six species described by Raymond (1944) from Mazon Creek are synonymized with E. danae. It is concluded that species diversity within the Carboniferous Xiphosura was low. The mode of life of E. danae is re-evaluated in the light of trace fossils recently described from Writhlington Geological Nature Reserve, and from palaeophysiological considerations. -from Author
... We here report new and exceptionally preserved specimens of Palaeocampa anthrax Meek & Worthen, 1865, with fossilized soft parts from Montceau-les-Mines. For two reasons these specimens are of more general interest. ...
... As for the taxonomic history of P. anthrax , it was originally described as a caterpillar from the Pennsylvanian (late Carboniferous) Mazon Creek, Illinois, in 1865 by Meek and Worthen (1865), and subsequently interpreted as a myriapod by Scudder (1882Scudder ( , 1884. More recently Pacaud et al . ...
... (1997), appears clear and is supported by the segmentally arranged parapodia with noto-and neurochaetae, as well as by the eversible proboscis. Meek and Worthen's (1865, 1866, 1868 suggestion that it is a caterpillar, as well as Scudder's (1868Scudder's ( , 1882Scudder's ( , 1884 suggestion that it belongs to Myriapoda, can be disregarded. ...
New records of Palaeocampa anthrax Meek&Worthen, 1865 with fossilized soft parts are provided from Montceau-les-Mines in France, late Carboniferous, permitting the identification of a new clade of extinct amphinomid polychaetes. The group also provides an object lesson for problems with species concepts in palaeontology. The biological species concept, the diagnosable phylogenetic species concepts, and the monophyletic phylogenetic species concepts are applied and discussed in the case of P. anthrax, as well as more generally in palaeontology. All three are rejected, but for different reasons. Instead we advocate the application of LITUs (least inclusive taxonomic unit), which refers to the smallest currently recognised taxa, but without making the unjustified rank assignments to species.
... Belinurids have been considered at length (Størmer, 1952;Eldredge, 1974;Anderson & Selden, 1997;Haug et al., 2012;Haug & Haug, 2020) and the presence of hypertrophied genal spines or complete loss of genal spines characterizes the group. Furthermore, phylogenetic analyses illustrated that Belinurina was a monophyletic superfamily traditionally thought to contain Alanops (Racheboeuf, Vannier & Anderson, 2002), Anacontium (Raymond, 1944), Belinurus (Pictet, 1846), Euproops (Meek & Worthen, 1865), Liomesaspis (Raymond, 1944), and Prolimulus (Fritsch, 1899). Despite the interest in belinurids, an array of species described in the early 20th century require revision (see Lamsdell & McKenzie, 2015;Bicknell et al., 2019a: Bicknell, Lustri & Brougham, 2019Bicknell & Pates, 2020;Bicknell & Smith, in press for revisions of similar historical material). ...
... Horseshoe crab clustering is well documented in extant species (Shuster Jr, 1982;Brockmann, 1990;Brockmann, 2003;Brockmann, Nguyen & Potts, 2000;Brockmann et al., 2015); however, exceptionally rare in the horseshoe crab fossil record. Indeed, the only evidence is one possible Euproops danae (Meek & Worthen, 1865) cluster (Ambrose & Romano, 1972;Fisher, 1979;Bicknell, Pates & Botton, 2019). NM Me 108 (Fig. 7) therefore illustrates that clustering was potentially more common than previously thought and was employed by multiple belinurid genera. ...
Xiphosurida is an ingroup of marine Euchelicerata often referred to as “living fossils”. However, this oxymoronic term is inapplicable for Paleozoic and early Mesozoic forms, as during these periods the group experienced notable evolutionary radiations; particularly the diverse late Palaeozoic clade Belinurina. Despite the iconic nature of the group, select species in this clade have been left undescribed in the light of recent geometric morphometric and phylogenetic considerations and methodologies. To this end, we re-describe Prolimulus woodwardi Fritsch, 1899 using new and type specimens to reveal more details on appendage anatomy and possible ecology. Furthermore, we present geometric morphometric and phylogenetic analyses that uncover relationships between P. woodwardi and other belinurids without genal spines. Both approaches highlight that a clade containing Prolimulus Fritsch, 1899, Liomesaspis Raymond, 1944, Alanops Racheboeuf, Vannier & Anderson, 2002 and Stilpnocephalus Selden, Simonetto & Marsiglio, 2019 may exist. While we do not erect a new group to contain these genera, we note that these genera exemplify the extreme limits of the Belinurina radiation and a peak in horseshoe crab diversity and disparity. This evidence also illustrates how changes in heterochronic timing are a key evolutionary phenomenon that can drive radiations among animals.
... Richard Raymond, a fossil enthusiast and nephew to the wellknown paleontologist Percy E. Raymond, began in the late 1950s to study well-preserved specimens of the Pennsylvanian horseshoe crab Euproops danae (Meek & Worthen, 1865). These were collected originally by geologist John C. Ferm and a team of other scientists from an abandoned strip mine 9.4 km south from Windber, Pennsylvania, USA (Fig. 1). ...
... Euproops danae (Meek & Worthen, 1865) Synonymy and references: A comprehensive list can be found in Babcock & Merriam (2000); the following are post-2000 additions to that list. Emended diagnosis: "Posterior of cardiac lobe constricted and bears a median tubercle. ...
Examination of 36 specimens of the Pennsylvanian horseshoe crab Euproops danae (Meek & Worthen, 1865) from a previously unreported occurrence in the lower Mercer Shale exposed in an abandoned strip mine south from Windber, Pennsylvania, USA, document ontogen-etic changes in prosomal morphology. Intercardiophthalmic transverse bars become less pronounced as ophthalmic spines become longer in larger, older specimens through approximately seven instar stages. It remains unclear if the presence or absence of ophthalmic spines is taphonomic, regardless of developmental stage. The holotype of E. danae is illustrated photographically for the first time.
... Geographical distribution patterns based on extant species supported a Nearctic realm origin for spiders. For many years, fossilized arachnids have been found in the Upper Carboniferous coal systems of Europe and North America (Corda 1835;Buckland 1837;Meek and Worthen 1865). Uraraneida was once considered the closest relative of Araneae, and only two species of two genera have been found in its current position. ...
In this study, we performed a comparative analysis based on a total of 255 spider mitogenomes and four outgroups, of which the mitogenomes of 39 species were assembled de novo, to explore the phylogenetic relationships and the adaptive evolution of mitogenomes. Results showed that Argyroneta aquatica had the longest mitochondrial length and the most pronounced codon preference to be UUA, followed by CCU. Codon usage frequencies were similar between families and codon usage in the mitogenome of spiders was mainly influenced by natural selection pressures rather than G/C mutation bias. Our phylogenetic topology clearly explained the evolutionary relationships among the spiders, and divergence time estimates indicated that the spiders originated in the early Devonian, and that the two clades of Mesothelae and Opisthothelae separated in the late Carboniferous. Ancestral range and trait reconstruction results supported the ancestral origin of spiders to the Devonian Nearctic realm, with the trapdoor being the original trait. Selection analysis detected positive selection signals in the ATP8 gene in Desis jiaxiangi. The ND5 gene is a convergent evolutionary gene between D. jiaxiangi and A. aquatica. Positive selection signals in the ATP8 gene and convergent selection sites in the ND5 gene may facilitate metabolic adaptation to the aquatic environment in two aquatic spiders. In conclusion, our analysis contributes to a better understanding of the taxonomic status, species diversity, mitochondrial characteristics, and environmental adaptations of these spiders.
... Systematic knowledge of these plants has been discussed in the past and resulted in some monographs and doctoral theses, on which we rely (e.g., Brongniart, 1828;Boulay, 1876Boulay, , 1879Zeiller, 1886Zeiller, -1888Carpentier, 1913;Danzé-Corsin, 1953;Danzé, 1956;Buisine, 1961;Crookal, 1964Crookal, , 1969Laveine, 1967Laveine, , 1987Laveine et al., 1978Laveine et al., , 1992Laveine et al., , 1998Laveine & Goubet, 1995;Laveine & Belhis, 2007). These layers have also delivered horseshoe crabs Euproops danae (Meek & Worthen, 1865) and Valloisella lievinensis Racheboeuf, 1992(Mathieu, 1945Racheboeuf, 1992). Data currently discussed belong to the upper Carboniferous (Moscovian) locally named the Bruay Formation (viz. ...
Plant-animal interactions shed light on the ecology of the rich insect community from the middle Pennsylvanian basin of Northern France (Nord-Pas-de-Calais coal basin, Hauts-de-France). The data set derives from coal bed layers locally named the Bruay Formation and were collected on the slag heap. This work is a meta-analysis of the different types of damages caused by arthropods, especially insects, consisting of endophytic oviposition scars, holes, galls, bulges, and undetermined traces. These damage traces are associated with host plants belonging to Lycopsida, Medullosales, Pinopsida, and Polypodiopsida. The paleoenvironmental framework and mutualism within each community are also discussed. Based on the present discoveries in Northern France, these interactions may have occurred stratigraphically from Westphalian B (Anzin Formation) until to Westphalian C (Bruay Formation). Despite the limited fossilization potential and sampling difficulties due to slag heap bias, occurrences may be compared with other European localities of the Carboniferous age.
... Lerner and Lucas (2021) recently added to this record Palaeocaris secretanae Schram, 1984 from the Atrasado Fm. (Kasimovian) of New Mexico. We add here an additional fossil syncarid species to the North American fossil record, Palaeocaris retractata Calman, 1932, from the Bashkirian interval of the Manning Canyon Fm. of central Utah, USA, and discuss its importance with respect to the biostrati-graphic and paleogeographic distribution of Palaeocaris Meek and Worthen, 1865. The only publication concerning the Manning Canyon fossil syncarids was an abstract published in a regional journal (Call and Tidwell, 1987). ...
New records documented here demonstrate that Palaeocaris Meek and Worthen, 1865 was the most cosmopolitan and longest ranging (earliest Bashkirian to Gzhelian) fossil syncarid genus. It contains three species that are primarily known from occurrences in Euramerican Carboniferous Lagerstätten. Two of these species, P. typus Meek and Worthen, 1865 and P. secretanae Schram, 1984, have previously been reported from North America. We add a third species to the North American fossil record, Palaeocaris
retractata Calman, 1932, from the Manning Canyon Formation (Bashkirian) of north-central Utah, USA. This is the oldest geological record of Palaeocaris and extends the temporal range of P. retractata back from its appearance in the transitional Bashkirian to Moscovian Bickershaw Lagerstätte of England by at least 4 million years. The Manning Canyon Formation occurrence expands the paleogeographic distribution
of P. retractata from western Europe (England) to the northeastern edge of the Great Basin, USA.
... Lerner and Lucas (2021) recently added to this record Palaeocaris secretanae Schram, 1984 from the Atrasado Fm. (Kasimovian) of New Mexico. We add here an additional fossil syncarid species to the North American fossil record, Palaeocaris retractata Calman, 1932, from the Bashkirian interval of the Manning Canyon Fm. of central Utah, USA, and discuss its importance with respect to the biostrati-graphic and paleogeographic distribution of Palaeocaris Meek and Worthen, 1865. The only publication concerning the Manning Canyon fossil syncarids was an abstract published in a regional journal (Call and Tidwell, 1987). ...
New records documented here demonstrate that Palaeocaris Meek and Worthen, 1865 was the most cosmopolitan and longest ranging (earliest Bashkirian to Gzhelian) fossil syncarid genus. It contains three species that are primarily known from occurrences in Euramerican Carboniferous Lagerstätten. Two of these species, P. typus Meek and Worthen, 1865 and P. secretanae Schram, 1984, have previously been reported from North America. We add a third species to the North American fossil record, Palaeocaris retractata Calman, 1932, from the Manning Canyon Formation (Bashkirian) of north-central Utah, USA. This is the oldest geological record of Palaeocaris and extends the temporal range of P. retractata back
from its appearance in the transitional Bashkirian to Moscovian Bickershaw Lagerstätte of England by at least 4 million years. The Manning Canyon Formation occurrence expands the paleogeographic distribution of P. retractata from western Europe (England) to the northeastern edge of the Great Basin, USA.
... This has extended to palaeontological examples, highlighting that injuries and malformations observed today have a fossil record extending back to at least the Carboniferous (Bicknell et al. 2018d). Five abnormal fossil specimens have been depicted to-date: a Mesolimulus walchi (Desmarest, 1822) with a cephalothoracic injury, another M. walchi specimen with a cephalothoracic-thoracetronic injury, two Euproops danae (Meek and Worthen, 1865) specimens with cephalothoracic injuries, and a E. danae specimen with putative cephalothoracic scrapes (Bicknell et al. 2018d). In addition, microborings have been reported on xiphosurids from the Jurassic aged Kcynia Formation, Poland (Błażejowski et al. 2019). ...
Xiphosurids are marine chelicerates that have been subject to extensive biological and palaeontological scrutiny over the past two centuries. This research effort is fuelled by the unique anatomical and physiological characteristics of the group, a long fossil record with conserved morphology, and use as modern analogues for understanding extinct arthropod groups. Despite this extensive literature, abnormal xiphosurid specimens are somewhat understudied. Recent studies have documented malformed specimens, the majority of which are attributed to injuries and developmental complications. To augment this recent research, we present records of Limulus polyphemus and Tachypleus tridentatus with malformed with malformed appendages, cephalothoraces, thoracetrons, and telsons. Causes of abnormalities are discussed and attributed to moulting issues and injuries. Three new examples of abnormal fossil xiphosurids are also presented: Euproops danae and Mesolimulus walchi specimens with cephalothoracic injuries and one specimen of M. walchi displaying a curved telson. We conclude that documenting abnormalities within populations may aid identification of spawning areas that require conservation attention. These oddities represent a potential avenue to minimize the population threats currently facing these unique chelicerates.KeywordsAbnormalitiesXiphosurida
Limulus polyphemus
Tachypleus tridentatus
Euproops danae
Mesolimulus walchi
Conservation
... Common species of flora found in associated members of the Shelburn Formation include Pecopteris miltoni Brongniart, 1828;Pecopteris unita (Brongniart, 1836); and Neuropteris flexuosa Sternberg, 1825(Boneham, 1974, which resembles the Mazon Creek Braidwood Flora (Patrick, 1989). The most common animal is the horseshoe crab Euproops danae Meek andWorthen, 1865 (Boneham, 1974). As indicated by the Shelburn Formation flora and fauna (which also includes the phalangiotarbid, Triangulotarbus terrehautensis Patrick, 1989), the depositional setting is consistent with that of an emergent swamp/ coastal freshwater environment with high turbidity and low salinity levels (Patrick, 1989). ...
A new specimen of the arachnid order Trigonotarbida is described from the Middle Pennsylvanian (lower Desmoinesian) Shelburn Formation of Indiana, which has previously yielded the remains of a phalangiotarbid. Two new trigonotarbid arachnid specimens are also described from the Middle Pennsylvanian (Desmoinesian) Senora Formation of Oklahoma. These are the first trigonotarbid specimens reported from Indiana and Oklahoma. The Indiana trigonotarbid belongs to the Eophrynidae, as indicated by distinct features such as the large tubercles on the dorsal surface of the opisthosoma and two pairs of terminal opisthosomal spines. This specimen is the first arachnid fossil to be imaged using a Multistripe Laser Triangulation scanner. The heavy dorsal tuberculation, lobed and subtriangular carapace, rounded clypeus, lack of terminal opisthosomal spines, and rounded opisthosoma on Oklahoma specimen FMNH PE 56932 indicate it belongs to the genus Aphantomartus , in Aphantomartidae. The other Oklahoma specimen, FMNH PE 56955, possesses opisthosomal tergites that are divided into five plates longitudinally as well as a subquadrate carapace, which identify it as a member of Anthracomartidae; its rounded opisthosomal margin shows it to belong to the genus Anthracomartus .
... Euproops Meek and Worthen, 1865;Packard, 1885;Chernyshev, 1928;Raymond, 1945;Copeland, 1957b;Murphy, 1970;Ambrose and Romano, 1972;Fisher, 1979;Anderson, 1994;Shuster, 2001;Rudkin and Young, 2009;Lucas et al., 2014;Bicknell et al., 2018dHaug and Rötzer, 2018b;Shpinev, 2018;Tashman et al., 2019;Haug and Haug, 2020 Figure 19 Euproops Euproops orientalis Kobayashi, 1933 Belinuridae Jido Series, Korea Carboniferous Freshwater Kobayashi, 1933 Figure 20C (Continued) ...
Horseshoe crabs are an iconic group of extant chelicerates, with a stunning fossil record that extends to at least the Lower Ordovician (~480 million years ago). As such, the group has retained significant biological and palaeontological interest. The sporadic nature of descriptive and systematic research into fossil horseshoe crabs over the last two centuries has spread information on the group across more than 200 texts dating from the early nineteenth century to the present day. We present the most comprehensive pictorial atlas of horseshoe crabs to date to pool these important data together. This review highlights taxa such as Bellinurus lacoei and Limulus priscus that have never been documented with photography. Furthermore, key morphological features of the true horseshoe crab (Xiphosurida) families—Austrolimulidae, Belinuridae, Limulidae, Paleolimulidae, and Rolfeiidae—are described. The evolutionary history of horseshoe crabs is reviewed and the current issues facing any possible biogeographic work are presented. Four major future directions that should be adopted by horseshoe crab researchers are outlined. We conclude that this review provides the basis for innovative geographic and geometric morphometric studies needed to uncover facets of horseshoe crab evolution.
... Euproops Meek and Worthen, 1865;Packard, 1885;Chernyshev, 1928;Raymond, 1945;Copeland, 1957b;Murphy, 1970;Ambrose and Romano, 1972;Fisher, 1979;Anderson, 1994;Shuster, 2001;Rudkin and Young, 2009;Lucas et al., 2014;Bicknell et al., 2018dHaug and Rötzer, 2018b;Shpinev, 2018;Tashman et al., 2019;Haug and Haug, 2020 Figure 19 Euproops Euproops orientalis Kobayashi, 1933 Belinuridae Jido Series, Korea Carboniferous Freshwater Kobayashi, 1933 Figure 20C (Continued) ...
... A particularly acute problem for coding xiphosurans into phylogenetic matrices is the lack of representative taxa that preserve characters pertaining to the appendages. So far, these data are limited primarily to Alanops magnificus Racheboeuf et al., 2002, Euproops danae (Meek andWorthen, 1865), Tachypleus syriacus (Yunnanolimulus luopingensis Zhang et al., 2009(Bicknell et al., 2019bHaug and Rötzer, 2018;Haug et al., 2012;Hu et al., 2017;Lamsdell and McKenzie, 2015). The discovery of more xiphosurans and xiphosurids with complete appendages would therefore contribute a plethora of new morphological data that can aid in refining phylogenetic hypotheses. ...
Horseshoe crabs are an iconic group of marine chelicerates that have an impressive fossil record extending back to at least the Lower Ordovician. Despite their long fossil record and associated palaeontological interest, a range of fossil horseshoe crab taxa erected in the 19th and 20th centuries have remained understudied. Recent phylogenetic hypotheses have led to improvements in the understanding of xiphosuran origins and evolutionary history; however, the resolution among the basal-most Devonian-aged members remains poor. Here, the type specimen of “Bellinurus” carteri Eller, 1940 from the Late Devonian of Pennsylvania is reconsidered. Based on a revised morphological description and comparison, we conclude that the species is not referable to the genus Bellinurus and erected a new genus: Pickettia gen. nov. A phylogenetic analysis resolves Pickettia carteri within a polytomy containing taxa previously considered to comprise the group Kasibelinuridae, but which is currently a paraphyletic assemblage. We discuss P. carteri within the context of other stem xiphosurids and conclude that the diversity of this assemblage has been overstated. The redescription of P. carteri highlights the need for more inclusive studies to resolve the evolutionary relationships of stem xiphosurids.
... Reports of exceptionally preserved horseshoe crab appendages contribute important anatomical information for constructing phylogenies of Xiphosurida (Farley 2010;Lamsdell and McKenzie 2015) and for interpreting the life modes of fossil taxa (Hu et al. 2017). To explore the possibly conserved nature of fossil horseshoe crab appendages, we compared Tachypleus syriacus appendages to those of nine fossil xiphosurid taxa: three belinurids [Alanops magnifica Racheboeuf, Vannier andAnderson, 2002, Euproops sp. in Haug et al. (2012), and Euproops danae (Meek and Worthen, 1865)], a paleolimulid [Paleolimulus signatus (Beecher 1904)], a possible austrolimulid (Casterolimulus kletti Holland, Erickson and O'Brien, 1975), and four limulids [Mesolimulus walchi (Desmarest 1822), Psammolimulus gottingensis Lange, 1923, Victalimulus mcqueeni Riek and Gill, 1971, and Yunnanolimulus luopingensis Zhang, Hu, Zhou, Lü, and Bai, 2009, and 11, Table 2). ...
Xiphosurida—crown group horseshoe crabs—are a group of morphologically conservative marine chelicerates (at least since the Jurassic). They represent an idealised example of evolutionary stasis. Unfortunately, body fossils of horseshoe crabs seldom preserve appendages and their associated features; thus, an important aspect of their morphology is absent in explorations of their conservative Bauplan. As such, fossil horseshoe crab appendages are rarely considered within a comparative framework: previous comparisons have focussed almost exclusively on extant taxa to the exclusion of extinct taxa. Here, we examine eight specimens of the xiphosurid Tachypleus syriacus (Woodward, 1879) from the Cenomanian (ca 100 Ma) Konservat-Lagerstätten of Lebanon, five of which preserve the cephalothoracic and thoracetronic appendages in exceptional detail. Comparing these appendages of T. syriacus with other fossil xiphosurids highlights the conserved nature of appendage construction across Xiphosurida, including examples of Austrolimulidae, Paleolimulidae, and Limulidae. Conversely, Belinuridae have more elongate cephalothoracic appendages relative to body length. Differences in appendage sizes are likely related to the freshwater and possible subaerial life modes of belinurids, contrasting with the primarily marine habits of other families. The morphological similarity of T. syriacus to extant members of the genus indicates that the conserved nature of the generic lineage can be extended to ecological adaptations, notably burrowing, swimming, possible diet, and sexual dimorphism.
... The trackway itself is orders of magnitude larger than those of Kouphichnium described from elsewhere in the Carboniferous (e.g. Goldring and Seilacher 1971;Chrisholm 1983;Romano and Melendez 1985;Archer et al. 1995;Buatois et al. 1998Buatois et al. , 2005Prescott et al. 2014) and is larger than all of the known xiphosurid body fossils from the late Paleozoic (Meek and Worthen 1865;Copeland 1957;Anderson et al. 1997;Shabica and Hay 1997;Babcock et al. 2000;Lerner et al. 2016). ...
The ichnogenus Kouphichnium and associated ichnofossils attributed to xiphosuran activity are here re-examined from samples collected from the Pennsylvanian-aged Steven C. Minkin Fossil Site at the Union Chapel Mine, in Walker County, Alabama, USA. The large sample size offers an unique opportunity to evaluate some Kouphichnium ichnospecies. Thus, the morphological variability resulting from the taphonomic, ethological, taxonomic variability and underprint fallout are evaluated using this large sample set. Three morphotypes have been segregated from the material previously assigned to K. aspodon discovered at this and adjacent sites. Ichnospecies of Kouphichnium identified at the Union Chapel Mines site include: K. lithographicum, K. aspodon and two new ichnospecies (K. atkinsoni and K. minkinensis). Additionally, Kouphichnium-like traces that are associated with “jumper” traces have been previously misinterpreted as Kouphichnium and Selenichnites, respectively, and are excluded from this study, leaving them in open nomenclature as they will be the subject of a subsequent publication. We here redescribe the holotype of K. aspodon and designate lectoparatypes to better define the ichnospecies. New trace makers for some Kouphichnium ichnospecies are hypothesized, in contrast to the traditional xiphosuran attribution.
... Therefore, they play a key role in our understanding of annelid evolution. The oldest known Amphinomidae from the fossil record are members of the genus Palaeocampa that occured in the late Carboniferous (Meek and Worthen, 1865;Thompson, 1979;Pleijel et al., 2004;Parry et al., 2014). Like many other annelids, amphinomids possess a high regenerative ability as demonstrated for Eurythoe complanata (anterior and posterior regeneration), Hermodice carunculata (posterior), or Linopherus canariensis (anterior and posterior) and described for asexual reproduction as well as a response to traumatic injury (Kudenov, 1974;M€ uller et al., 2003;Cosentino and Giacobbe, 2011;Ahrens et al., 2014;Y añez-Rivera and M endez, 2014). ...
Amphinomidae or so-called “fireworms” are known for their inflammatory substances and their regeneration ability. Recent transcriptome-based molecular analyses revealed that these remarkable annelids are a basal branching taxon outside the annelid main radiation (Pleistoannelida). Although several studies dealing with analyses of the morphology of these annelids have been published, detailed investigations of the anterior muscle regeneration and the musculature in general are largely lacking for amphinomids. Using histology, phalloidin labeling together with subsequent confocal laser scanning microscopy (cLSM), and further light microscopic image acquisition of different regeneration stages, we here present the first morphological study describing the myoanatomy and muscular regeneration. During anterior muscular regeneration, longitudinal muscle bundles develop prior to transverse muscle fibers and segment boundaries. Additionally, Eurythoe cf. complanata develops an independent muscular ring surrounding the mouth opening in an early stage of regeneration. Detailed investigation of adult body wall musculature and the parapodial muscle complex in amphinomids show that E. cf. complanata bears well-developed dorsal and ventral longitudinal muscle bundles as well as outer transverse muscles comparable to the pattern described for several Pleistoannelida. Furthermore, the biramous parapodia possess a complex meshwork of distinct muscle fibers allowing detailed comparisons with other annelid families.
... Arachnids have been known as fossils from the Upper Carboniferous Coal Measures of Europe and North America for many years (Corda 1835;Buckland 1837;Meek and Worthen 1865). Economic exploitation of coal resources during the late 19th and early 20th centuries, together with the popularity of fossil hunting on the associated spoil heaps, contributed greatly to these discoveries. ...
New finds of Late Palaeozoic arachnids, based on three well-preserved carapaces from the Carboniferous of Russia and Ukraine and one complete, albeit poorly preserved, specimen from the Permian of Kazakhstan, are described. The spider genus Arthrolycosa is reported from the Late Carboniferous (Late Pennsylvanian: Kasimovian–Gzhelian) of Chunya in the Tunguska Basin of Siberia; it is the first find of a spider outside the Carboniferous tropics. Another fossil assigned to the same genus comes from the Late Carboniferous (Early Pennsylvanian: Bashkirian) of Kamensk–Shakhtinsky in the Donets Basin of Russia; it is probably the oldest fossil spider known. A thelyphonid (whip scorpion) carapace is described from the Late Carboniferous (Late Pennsylvanian: Kasimovian) of the adjacent Lugansk Province of the Donets Basin of Ukraine.
... , several annelid forms occur in the Montceau Lagerstätte, including the amphinomid Palaeocampa anthrax Meek and Worthen, 1865 with preserved parapodia and chaetae (Pleijel et al., 2004; Fig. 4A). The rest of the annelid material is still unstudied. ...
The Montceau-les-Mines Lagerstatte (Late Stephanian, Late Carboniferous) is located northeast of the French Massif Central. Situated at equatorial latitudes during the Pennsylvanian, this Lagerstatte, probably a freshwater environment, preserves a rich and diverse flora (lycopsids, sphenopsids, ferns, pteridosperms, and cordaites) and fauna (bivalves, annelids, crustaceans, myriapods, insects, chelicerates, myxinoids, actinopterygians, sarcopterygians and tetrapods). These exceptionally preserved fossils can be found either flattened in shales or three-dimensionally preserved in sideritic nodules. The fossils from the nodules are exceptional for at least two reasons: the absence of major disarticulation of their body structure and the preservation of soft parts and extremely fragile cuticular structures. Such preservation was made possible by the combination of several factors: rapid burial in fine anoxic mud, early siderite precipitation (inducing the nodule formation) and phosphatization of cuticles and soft-bodied features.
... In addition to the vaulted carapace and free lobes which are characteristic of benthic forms, and not of swimmers that lack these (Fisher 1975), the heavily sculptured thoracetron and long genal spines of Xaniopyramis are uncharacteristic of limuloids which habitually swim. Long spines are no hindrance to small swimming xiphosurids like Euroops danae (Meek & Worthen, 1865) (Fisher 1977b) and Rolfeia (Waterston 1985) and can be advantageous in aiding passive settling of the coapted animal as a defence mechanism, but larger swimming animals lack spines which minimizes drag effects. Such forms, for example Dubbolimulus Pickett, 1984, have the sculpture of carapace and thoracetron effaced thereby reducing drag, whereas Xaniopyramis clearly does not. ...
One of the largest xiphosurid specimens known from the fossil record, found in the lower Namurian strata of Weardale, is described as Xaniopyramis linseyi gen. et sp. nov. It is referred to the Limuloidea, Moravuridae Pribyl, 1967. Xaniopyramis was probably a burrowing form and a poor swimmer; it is the first xiphosurid body fossil recorded from the British Namurian and supports the idea of a marine faunal connection at this time with the central-E European area.-Authors
Fossil-Lagerstätten, or Lagerstätten, have played a critical role in our understanding of the diversity, abundance, evolution, and systematics of marine arthropods. The tendency toward preservation of Phanerozoic marine arthropods as fossils generally increases as a factor of biomineralization. Concentration deposits (Konzentrat-Lagerstätten) tend to have an abundance of biomineralized arthropod taxa, whereas conservation deposits (Konservat-Lagerstätten) tend to produce a higher biodiversity that includes biomineralizing and non-biomineralizing taxa. Some Lagerstätten incorporate aspects of both concentration and conservation deposits, indicating that these concepts are idealizations, or preservational end members. For arthropod occurrences, it is useful to consider another dimension of Lagerstätten: their taphonomic associations. This leads to a more nuanced understanding of arthropod fossilization history. Four taphonomic associations account for a substantial number of marine arthropod occurrences: (1) concretions, (2) clusters, (3) event beds, and (4) microbially sealed sediments. Each of these occurrences can blur the distinctions between, or the means of recognizing, the idealized genetic categories of concentration deposits and conservation deposits.
Xiphosuran chelicerates, also known as horseshoe crabs, are a long-lived clade characterized by a highly distinctive morphology and are a classic example of supposed evolutionary stasis. One key feature of horseshoe crabs is the fusion of the opisthosomal segments into a single sclerite referred to as a thoracetron. There has been historical uncertainty as to whether the thoracetron originated once or multiple times within the clade. Here we review criteria for determining whether segments are fused and apply them to a broad census of taxa for which their ontogeny is known or the adult status of specimens can be reasonably asserted to explore the evolution of the thoracetron within a developmental framework. Our findings indicate that the thoracetron evolved once in the common ancestor to Xiphosura. However, subsequent independent loss of the thoracetron segment boundaries is identified and shown to be the result of heterochronic processes acting on a shared developmental pathway. The multiple cases of effacement of the thoracetron within Limuloidea are cases of peramorphically driven parallelism, while the effacement of the thoracetron in the pedomorphic Belinurina is a case of convergence. Xiphosurids therefore represent an interesting case study for recognizing parallelism and convergence on the same structure within closely related lineages. We also demonstrate that somite VII has been incorporated into the prosoma multiple times within the chelicerate lineage, which has implications for interpreting the ground pattern of the group.
Two malacostracan crustacean genera are described from the Langsettian (upper part of the Bashkirian, Lower Pennsylvanian) of the Scottish Coal Fields in the Midland Valley of Scotland. One is the youngest occurrence of Tealliocaris Peach, 1908 and was found at Polkemmet Colliery near Whitburn. It is recognised as a new species, Tealliocaris elliotti , based on the presence of eight spines on its scaphocerites and lateral convergent carinae of the telson. The other crustacean is a unique specimen from the Ardenrigg Colliery at Wester Bracco, North Lanarkshire in similar shales of Langsettian age. There are no distinguishing characters preserved that would identify it as a new species, but it can be placed in Palaeocaris Meek and Worthen, 1865 based on the well preserved features of the tail fan. This is the first record of this genus in Scotland, although specimens of Minicaris brandi Schram, 1979 from the Namurian (Serpukhovian, Upper Mississippian) shales of Bearsden are now here also considered to be a species of Palaeocaris .
Concretions are an interesting mode of preservation that can occasionally yield fossils with soft tissues. To properly interpret these fossils, an understanding of their fossilization is required. Probabilistic models are useful tools to identify variations between different Konservat-Lagerstätten that are separated spatially and temporally. However, the application of probabilistic modeling has been limited to Early Paleozoic Konservat-Lagerstätten preserved in shales. In this paper, the patterns of preservation of three concretionary Konservat-Lagerstätten—the Carboniferous Mazon Creek (USA) and Montceau-les-Mines (France), and the Silurian Herefordshire Lagerstätte (UK)—are analyzed using a statistical approach. It is demonstrated that the degree of biotic involvement, i.e., the degree to which a carcass dictates its own preservation, is connected to internal organ conditional probabilities—the probabilities of finding an internal organ associated with another structure such as biomineralized, sclerotized, cuticularized, or cellular body walls. In concretions that are externally forced with little biological mediation (e.g., Herefordshire), all internal organ conditional probabilities are uniform. As biological mediation in concretion formation becomes more pronounced, heterogeneities in conditional probabilities are introduced (e.g., Montceau-les-Mines and Mazon Creek). The three concretionary sites were also compared with previously investigated Konservat-Lagerstätten preserving fossils in shales to demonstrate how the developed probability framework aids in understanding the broad-scale functioning of preservation in Konservat-Lagerstätten.
Supplementary Information
The online version contains supplementary material available at 10.1186/s13358-023-00284-4.
Horseshoe crabs (Xiphosura) have a long evolutionary history starting in the Ordovician, but they have rarely been reported from the Netherlands. We report on the first Triassic horseshoe crab from the Netherlands identifiable to the species level, a specimen of the limulid Limulitella bronnii . We provide the first diagnosis for this species and refigure the holotype. The new specimen was found in the Middle Triassic (Anisian) Muschelkalk sediments of the Vossenveld Formation, in the Illyrian part of the stratigraphic profile of the Winterswijk quarry complex. The Winterswijk specimen represents the youngest occurrence of L. bronnii . The inferred non-marine habitat of this horseshoe crab species elsewhere in conjunction with occurrences of plant and insect remains within the same layer at Winterswijk suggest the specimen herein most probably did not live in marine conditions either. This species has previously been found in non-marine sediments in France and Germany, expanding its geographic range northward. Several faunal elements from Winterswijk including L. bronnii show resemblance to the roughly co-eval non-marine components of the Anisian Grès à Voltzia Formation in NE France, suggesting a paleobiogeographic connection between these regions in Western Europe.
Records of evolutionary stasis over time are central to uncovering large-scale evolutionary modes, whether by long-term gradual change or via enduring stability punctuated by rapid shifts. The key to this discussion is to identify and examine groups with long fossil records that, ideally, extend to the present day. One group often regarded as the quintessential example of stasis is Xiphosurida, the horseshoe crabs. However, when, how and, particularly, why stasis arose in xiphosurids remain fundamental, but complex, questions. Here, we explore the protracted history of fossil and living xiphosurids and demonstrate two levels of evolutionary stability: developmental stasis since at least the Pennsylvanian and shape stasis since the Late Jurassic. Furthermore, shape and diversity are punctuated by two high-disparity episodes during the Carboniferous and Triassic-transitions that coincide with forays into habitation of marginal environments. In an exception to these general patterns, body size increased gradually over this period and, thus, cannot be described under the same, often-touted, static models of evolution. Therefore, we demonstrate that evolutionary stasis can be modular and fixed within the same group at different periods and in different biological traits, while other traits experience altogether different evolutionary modes. This mosaic in the tempo and mode of evolution is not unique to Xiphosurida but likely reflects variable mechanisms acting on biological traits, for example transitions in life modes, niche occupation and major evolutionary radiations.
An exceptionally preserved specimen of the horseshoe crab Euproops danae (Xiphosurida, Belinurina) in a siderite concretion from the Carboniferous (Upper Pennsylvanian, Virgilian) Lawrence Formation, Kansas, shows anatomical details of the prosomal musculature. The extrinsic appendicular muscles are comparable to those of Limulus polyphemus (the modern American horseshoe crab), demonstrating anatomical conservatism within Xiphosurida that spans two morphologically disparate subgroups , Belinurina and Limulina. The three-dimensional preservation of muscles highlights how siderite concretion fossils (including those of the Mazon Creek Konservat-Lagerst€ atte) have better preservational fidelity than previously realized and the potential to reveal new anatomical information, especially with regard to the labile tissues of euarthropods.
In the first half of the nineteenth century, a marked shift occurred in our understanding and treatment of the chelicerate fossil record, with the differentiation and recognition of entirely extinct genera for the first time. At the heart of this taxonomic revolution were the Eurypterida (sea scorpions) and Xiphosura (horseshoe crabs), although both groups were in fact considered crustaceans until Lankester's (1881) seminal comparative anatomical study of the extant xiphosuran Limulus Müller, 1785 and modern scorpions. The oldest available eurypterid genus is Eurypterus deKay, 1825; the oldest available fossil arachnid genus name is that of the scorpion Cyclophthalmus Corda, 1835. However, there has been considerable historical confusion over the oldest available fossil xiphosuran genus name, which has been recognized alternately as Belinurus König (with a publication date of either 1820 or 1851) or the synonymous Bellinurus Pictet, 1846. Most recent treatments (e.g., Selden and Siveter, 1987; Anderson and Selden, 1997; Anderson et al., 1997; Lamsdell, 2016, 2021; Bicknell and Pates, 2020) have favored Bellinurus Pictet, 1846 as the available name; however, Haug and Haug (2020) recently argued that Belinurus König, 1820 is valid and has priority, a position then followed by Lamsdell (2020), prompting a reinvestigation of the taxonomic history of the genus. Upon review, it is clear that neither of the previously recognized authorities for Belinurus are accurate and that the two candidate type species for each genus are, in fact, synonyms. Given the convoluted and at times almost illogical history of the competing names, along with the most recent controversy as to which has priority, we present a complete history of the treatment of the genus to resolve the issue.
Xiphosurans are aquatic chelicerates with a fossil record extending into the Early Ordovician and known from a total of 88 described species, four of which are extant. Known for their apparent morphological conservatism, for which they have gained notoriety as supposed ‘living fossils’, recent analyses have demonstrated xiphosurans to have an ecologically diverse evolutionary history, with several groups moving into non-marine environments and developing morphologies markedly different from those of the modern species. The combination of their long evolutionary and complex ecological history along with their paradoxical patterns of morphological stasis in some clades and experimentation among others has resulted in Xiphosura being of particular interest for macroevolutionary study. Phylogenetic analyses have shown the current taxonomic framework for Xiphosura—set out in the Treatise of Invertebrate Paleontology in 1955—to be outdated and in need of revision, with several common genera such as Paleolimulus Dunbar, 1923 and Limulitella Størmer, 1952 acting as wastebasket taxa. Here, an expanded xiphosuran phylogeny is presented, comprising 58 xiphosuran species as part of a 158 taxon chelicerate matrix coded for 259 characters. Analysing the matrix under both Bayesian inference and parsimony optimisation criteria retrieves a concordant tree topology that forms the basis of a genus-level systematic revision of xiphosuran taxonomy. The genera Euproops Meek, 1867, Belinurus König, 1820, Paleolimulus , Limulitella , and Limulus are demonstrated to be non-monophyletic and the previously synonymized genera Koenigiella Raymond, 1944 and Prestwichianella Cockerell, 1905 are shown to be valid. In addition, nine new genera ( Andersoniella gen. nov. , Macrobelinurus gen. nov. , and Parabelinurus gen. nov. in Belinurina; Norilimulus gen. nov. in Paleolimulidae; Batracholimulus gen. nov. and Boeotiaspis gen. nov. in Austrolimulidae; and Allolimulus gen. nov., Keuperlimulus gen. nov., and Volanalimulus gen. nov. in Limulidae) are erected to accommodate xiphosuran species not encompassed by existing genera. One new species, Volanalimulus madagascarensis gen. et sp. nov., is also described. Three putative xiphosuran genera— Elleria Raymond, 1944, Archeolimulus Chlupáč, 1963, and Drabovaspis Chlupáč, 1963—are determined to be non-xiphosuran arthropods and as such are removed from Xiphosura. The priority of Belinurus König, 1820 over Bellinurus Pictet, 1846 is also confirmed. This work is critical for facilitating the study of the xiphosuran fossil record and is the first step in resolving longstanding questions regarding the geographic distribution of the modern horseshoe crab species and whether they truly represent ‘living fossils’. Understanding the long evolutionary history of Xiphosura is vital for interpreting how the modern species may respond to environmental change and in guiding conservation efforts.
Descriptions of four xiphosuran species belonging to two genera, Bellinurus Pictet, 1846 and Prestwichianella Woodward, 1918 (currently included in Euproops Meek, 1867), which were described in the 1920s from the Carboniferous of the Donets Coal Basin, are reassessed based on modern knowledge of taphonomy and xiphosuran anatomy. Prestwichianella zalesskii Chernyshev, 1927 is here synonymized under Euproops danae (Meek et Worthen, 1865). New specimens of E. danae and Bellinurus sp. from the Carboniferous of the Donets Coal Basin are considered in view of associated floral and faunal assemblages and comparisons with floras and faunas from some previously described localities containing members of these genera.
Xiphosurida comprise an archetypal arthropod group of considerable interest to both biological and palaeontological researchers. This appeal is generated by a combination of unique anatomical features, utility as modern analogues for extinct arthropod groups, and an impressive fossil record. Although xiphosurids have been extensively studied, there are few published examples of abnormal specimens. Abnormalities in xiphosurids have mostly been attributed to injuries (either self-inflicted, from mating, or predation) or teratologies (developmental and genetic malfunctions). Here we summarise all previously recorded extant xiphosurid abnormalities and describe new examples of injuries and teratologies to Limulus polyphemus and Tachypleus tridentatus. Furthermore, we present the first evidence of injured fossil xiphosurids: Euproops danae and Mesolimulus walchi. We identify two main groups of telson teratologies and document new ‘U’ shaped cephalothoracic injuries to the anterior cephalothoracic margins of L. polyphemus and T. tridentatus. We show ‘V’ and ‘W’ shaped injuries to E. danae and M. walchi cephalothoracic sections. A further specimen of E. danae is described, which likely represents plastic deformation of a recently moulted exoskeleton, rather than an abnormality sensu stricto. We compare injuries on extant xiphosurids to extinct Cambrian trilobite injuries to suggest that rare cephalic injuries to trilobites were incurred during soft-shelled exoskeletal stages. Reviewing xiphosurid injuries through time is a pivotal step towards understanding how Recent and extinct arthropods responded to injuries.
The cystoporate bryozoan Glyptopora michelinia (Prout, 1860) was identified from the latest Viséan/earliest Serpukhovian of southern France. This species was known previously from the Mississippian of the USA and southwestern Spain. The morphology of the genus Glyptopora includes the development of bilaminate lobes. Such morphology became successful in several groups of cystoporate bryozoans and was regarded as efficient adaptation for feeding. Another explanation would be control by the type of substrate which enabled temporal success of lobate species against the encrusting ones in the Late Palaeozoic.
Tierische Fossilien aus dem Westfal D des Piesbergs bei Osnabrück sind seit 1860 vereinzelt immer wieder beschrieben worden. Doch erst durch die Funde der letzten 30 Jahre zählt der Piesberg zu den bedeutendsten Fundorten terrestrischer Fauna im Karbon. Erstmals werden 45 stratifiziert aufgesammelte Individuen von Euproops untersucht. Einige Details der Morphologie sowie eine dichte Behaarung werden beschrieben. Auf der Basis dieser Merkmale sowie der Verteilung juveniler und adulter Individuen im geologischen Profil wird eine Deutung des Lebensraumes der Euproopiden versucht. Danach hielten sich die juvenilen Individuen dieser Tiergruppe als Laubstreubewohner in feuchten Spülsäumen flacher ruhiger Gewässer und Laubstreuhorizonten auf. Die adulten Formen lebten vornehmlich benthisch in ufernahen Gewässern und verließen wohl nur noch gelegentlich das Wasser.
Since 1860 articulated fossils of terrestrial taxa have been described from lower Westfalian D sediments of the Piesberg section near Osnabrück (northwestern Germany). In this paper 45 individuals of the genus Euproops, sampled from particular levels in the profile, are reported on for the first time. Analysis of the fossil material reveals new morphological details – especially setae densely covering the ventral side – that, combined with the geological setting of the profile, gives novel insights into the palaeoenvironment and to the hypothesis of subaerial activity. Young individuals of Euproops may have been "litter dwellers" inhabiting forest-litter and partly decayed plant material that had washed ashore. By contrast, adults formed a principal component of the nearshore benthic fauna. They were able to leave the water, but only for short periods. This is proved by the occurence of adults and juveniles in different lithologies.
doi:10.1002/mmng.20000030105
Euproops danae , a xiphosuran from the Mazon Creek (Braidwood) Fauna, had two sets of spines—genal and ophthalmic—extending from the posterior margin of its prosoma. In young individuals, the genal spines were longer than the ophthalmic spines. During growth, the relative length of each type of spine increased, but the rate of increase was much greater for ophthalmic spines. In order to explain these morphological and ontogenetic features, I have studied the hydrodynamic behavior of whole-animal models representing the actual morphology of E. danae , and various modifications thereof, at different body sizes. It can be argued that passive settling, while in an enrolled posture, was probably the primary defensive reaction that a swimming individual would have exhibited in response to an encounter with a potential predator. Experiments show that the array of spines on E. danae was an important control on the style of settling experienced by an enrolled individual. Models of the actual morphology settle steadily, while models with either longer or shorter prosomal spines tend to undergo lateral oscillations induced by turbulence in the wake. Steady fall would have rendered the horseshoe crab less perceptible to either the visual or lateral line systems of contemporary aquatic vertebrates, and thus a morphology capable of producing it would have been an important adaptation for reducing the risk of predation. This minimization of oscillatory movement would actually obtain for a variety of conceivable spine morphologies, but actual morphologies represent those ‘solutions’ which simultaneously optimize other aspects of spine function, such as mechanical protection. This optimum design changes during ontogeny because settling dynamics scale non-linearly with size. This work has both specific applications to the interpretation of similar structures in other arthropods and more general implications for the study of evolutionary functional morphology.
Une faune à bryozoaires du Mississippien (Viséen) du Roque Redonde (Montagne Noire, Sud de la France).Une faune à bryozoaires est décrite du Mississippien (Viséen) du Roque de Redonde (Montagne Noire, Sud de la France). Cette faune comprend 38 espèces (12 cystoporatés, 2 trepostomés, 6 cryptostomés [rhabdomesinés], et 18 fenestrés), dont neuf espèces sont nouvelles : Fistulipora tolokonnikovae n. sp., Dybowskiella rotunda n. sp., Dybowskiella piriforme n. sp., Eridopora suarezi n. sp., Volgia deftera n. sp., Cystodictya gallensis n. sp., Megacanthopora enodata n. sp., Fabifenestella macrofenestrata n. sp., Baculopora redondensis n. sp. Un nouveau genre avec une nouvelle espèces est décrit: Gorjunopora gallica n. gen., n. sp. En plus, 23 espèces caractéristiques du Mississippien eurasiatique et nord-américaines sont identifiées. Les corrélations paléobiogéographiques sont variables. Celles les plus proches existent avec le Mississippien (Viséen) des Îles britanniques et de la plate-forme Russe. D'autres corrélations paléobiogéographiques existent avec le Mississippien de l'Allemagne, de l'Ukraine, de l'Espagne, du Bassin Kouznetsk, de l'Amérique du Nord et du Kazakhstan. La faune étudiée est majoritairement composée des morphologies fragiles ce qui suggère un milieu de vie dans un environnement peu agité.
Stenolaemate bryozoan fauna from the Lower Carboniferous (Mississippian) of southwestern Spain (Los Santos de Maimona Basin and Guadiato Area – Ossa Morena Zone) contains eight bryozoan species including three cystoporates, three trepostomes, and two cryptostomes. They range from
Asbian (Upper Viséan) to Pendleian (Serpukhovian). This fauna displays distinct palaeobiogeographic relationships to the Mississippian of Europe, USA, Siberia, and Japan
We document body fossils of the xiphosurid (horseshoe crab) Euproops danae Meek and Worthen from lacustrine black shale of the Missourian interval of the Beeman Formation near Alamogordo, New Mexico. These xiphosau-rids, associated with conchostracans, bivalves, microconchids, fish scales and a paleoflora, are from a likely freshwater lake deposit. This is the first report of E. danae from the western USA and the first documentation of xiphosurid body fossils in the Pennsylvanian of New Mexico.
Investigations of recently cracked concretions from the Carboniferous Montceau-les-Mines, France, Lagerstatte led to the recognition of two new malacostracan Crustacea: a palaeophreatoicid isopod, Sottyella montcellensis n. g. n. sp., and a gorgonophontid stomatopod, Chabardella spinosa n. g., n. sp. The occurrence of the palaeophreatoicid isopod Palaeocrangon is discussed, and a new specimen of the syncarid Palaeocaris secretanae allows us to clarify some of its morphological characters. The recognition of these taxa increases the faunal inventory of malacostracans in the Montceau-les-Mines Lagerstatte.
Are the Eumalacostraca issued from a model of Crustacea which the carapace would have disapeared later on in some of them, and persisted in others, or from one without carapace that some of its decendants would have acquired? In the two instances this ancestor would goes far back, seeing that, already, in the Devonian, Syncarida, Stomatopoda, Phyllocarida and Eocarida were differenciated. With regard to the preliminary survey on a fine material of Syncarida from the Stephanian of the region of Autun, comparisons between two models of Crustaceans from which the cephalon includes only sensorial and gnathal segments, without adjunction of any thoracic metamere, allow to specify the notion of carapace, and to surround the question. The great oldness of the origin of the phyla possessing or not possessing a carapace seems to exclude the hypothesis of a passing over from one model to the other and suggests a representation of the common ancestor which have to be searched in the Cambrian period.
Tierische Fossilien aus dem Westfal D des Piesbergs bei Osnabrück sind seit 1860 vereinzelt immer wieder beschrieben worden. Doch erst durch die Funde der letzten 30 Jahre zählt der Piesberg zu den bedeutendsten Fundorten terrestrischer Fauna im Karbon. Erstmals werden 45 stratifiziert aufgesammelte Individuen von Euproops untersucht. Einige Details der Morphologie sowie eine dichte Behaarung werden beschrieben. Auf der Basis dieser Merkmale sowie der Verteilung juveniler und adulter Individuen im geologischen Profil wird eine Deutung des Lebensraumes der Euproopiden versucht. Danach hielten sich die juvenilen Individuen dieser Tiergruppe als Laubstreubewohner in feuchten Spülsäumen flacher ruhiger Gewässer und Laubstreuhorizonten auf. Die adulten Formen lebten vornehmlich benthisch in ufernahen Gewässern und verließen wohl nur noch gelegentlich das Wasser.Since 1860 articulated fossils of terrestrial taxa have been described from lower Westfalian D sediments of the Piesberg section near Osnabrück (northwestern Germany). In this paper 45 individuals of the genus Euproops, sampled from particular levels in the profile, are reported on for the first time. Analysis of the fossil material reveals new morphological details - especially setae densely covering the ventral side - that, combined with the geological setting of the profile, gives novel insights into the palaeoenvironment and to the hypothesis of subaerial activity. Young individuals of Euproops may have been “litter dwellers” inhabiting forest-litter and partly decayed plant material that had washed ashore. By contrast, adults formed a principal component of the nearshore benthic fauna. They were able to leave the water, but only for short periods. This is proved by the occurence of adults and juveniles in different lithologies.
1997 04 15: Opisthosomal fusion and phylogeny of Palaeozoic Xiphosura. Lethaia, Vol. 30, pp. 19-31. Oslo. ISSN 0024-1 164. Fusion of opisthosomal tergites to form a thoracetron has previously been considered a char-acteristic of the xiphosuran superfamilies Euproopoidea Eller, 1938, and Limuloidea Zittel, 1885. Evidence is presented here that fusion also occurs in Bellinuroidea Zittel & Eastman, 1913. Results of a cladistic analysis of Palaeozoic xiphosuran genera indicate that Synziphosu-rina Packard, 1886, is a paraphyletic assemblage of stem-group Xiphosura. Superfamily Pale-olimulidae superfam. nov. is erected for families Paleolimulidae Raymond, 1944, and Moravu-ridae Pfibyl, 1967. OChelicerata, cladistics, evolution. Horseshoe crabs (Xiphosura) have been held up as the prime example of a 'living fossil' group -one that has remained conservative in morphology and at low diver-sity for much of its geological history (Fisher 1984). The distinctive features of a large carapace concealing the pro-soma1 appendages, fused opisthosomal tergites (a thora-cetron), and a styliform tail spine, can be traced back to Carboniferous times, when the group was apparently much more diverse than today. Three distinct groups of Carboniferous Xiphosura are generally recognized, the superfamilies Bellinuroidea Zittel & Eastman, 19 13, Euproopoidea Eller, 1938, and Limuloidea Zittel, 1885. The latter two groups share the possession of a thoracet-ron, whilst bellinuroids have hitherto been distinguished by their free opisthosomal tergites. During a restudy of upper Palaeozoic Xiphosura by one of us (LIA), it was dis-covered that all specimens that could be referred to Bell-inurus Pictet, 1846 (Fig. 2J), and also Bellinuroopsis Chernyshev, 1933 (Fig. 2M), have all post-opercular tergites fused into a thoracetron (Anderson 1995). This observation has important consequences for xiphosuran taxonomy and phylogeny. We present here the evidence for fusion in the opisthosoma of bellinuroids, followed by a phylogenetic analysis of late Palaeozoic Xiphosura to generic level. The character matrix relies to a large extent on new information resulting from restudy of large num-bers of late Palaeozoic xiphosurans, including all available holotypes. Further details are given by Anderson (1996), and taxonomic revisions will be published elsewhere. A major conclusion of this study is that Synziphosurina Packard, 1886, is a paraphyletic assemblage and the name must be abandoned; xiphosurans with a thoracetron (and other synapomorphies) are united herein in the order Xiphosurida Latreille, 1802.
A reassessment of the origin of the Limuloidea (Xiphosura) has been facilitated following recent descriptions of the two earliest known examples, of Carboniferous age: Rolfeia Waterston, 1985 from the Tournaisian of Scotland and Xaniopyramis Siveter & Selden, 1987 from the basal Namurian of England. Analysis of the nature of segment reduction from the more primitive to the advanced xiphosurids indicates that in the bellinuroid (limulicine) line caudal fusion was dominant, and supports the notion that the limuloids arose from an early bellinuroid in the late Devonian or earliest Carboniferous, from such as the late Devonian Neobelinuropsis Eller, whilst the euproopoids originated independently later in the Carboniferous via a different bellinuroid line. Rolfeia is the oldest limuloid, but the slightly younger Xaniopyramis is believed to be the first with a partially encephalized somite VIII, a feature thereafter diagnostically present in the limuloid lineage to Recent forms. Phylogenetically Xaniopyramis lies between Rolfeia and the Permo-Carboniferous Puleolimulus Dunbar, of the Paleolimulidae Raymond. Xaniopyramis belongs to the Moravuridae Přibyl; Rolfeia, previously provisionally considered to be a paleolimulid, is placed herein within the monotypic Rolfeiidae fam. nov.
Fusion of opisthosomal tergites to form a thoracetron has previously been considered a characteristic of the xiphosuran superfamilies Euproopoidea Eller, 1938, and Limuloidea Zittel, 1885. Evidence is presented here that fusion also occurs in Bellinuroidea Zittel & Eastman, 1913. Results of a cladistic analysis of Palaeozoic xiphosuran genera indicate that Synziphosurina Packard, 1886, is a paraphyletic assemblage of stem-group Xiphosura. Superfamily Paleolimulidae superfam. nov. is erected for families Paleolimulidae Raymond, 1944, and Moravuridae P&íbyl, 1967.
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