scholarly journals A basal aïstopod from the earliest Pennsylvanian of Canada, and the antiquity of the first limbless tetrapod lineage

2018 ◽  
Vol 5 (12) ◽  
pp. 181056 ◽  
Author(s):  
Jason D. Pardo ◽  
Arjan Mann
Keyword(s):  
Nova Scotia ◽  
New Genus ◽  
Taxonomic Diversity ◽  
Unique Representation ◽  
Vertebrate Fauna ◽  
Lower Jaw ◽  
Anterior Half ◽  
True Diversity ◽  
Fossil Assemblages

Earliest Pennsylvanian (Bashkirian) vertebrate fossil assemblages of the Joggins Formation (Cumberland Group) of Nova Scotia, Canada, have long been noted for the unique representation of the earliest known crown amniotes, but the overall vertebrate fauna remains poorly understood. The vast majority of Joggins vertebrates have historically been assigned to the Microsauria, a group originally established by Dawson specifically to accommodate the abundant, diminutive fossils of the Joggins Formation. As the Microsauria concept has evolved, some Joggins taxa (e.g. the eureptile Hylonomus lyelli ) have been removed from the group, but many of the Joggins ‘microsaurs’ remain unrevised, obscuring the true diversity of the earliest Pennsylvanian tetrapod fauna. Here we amend part of this problem by revisiting the morphology of Dawson's ‘microsaur’ Hylerpeton longidentatum . This taxon, represented by the anterior half of a left hemimandible, is here reinterpreted as a plesiomorphic aïstopod and assigned to a new genus, Andersonerpeton . A. longidentatum shows a surprisingly primitive anatomy of the lower jaw, retaining a parasymphyseal fang pair on the dentary, an adsymphyseal bone bearing a denticle field, fangs on all coronoids and parasymphyseal foramina, as well as a prearticular which extends far anterior along the coronoid series. However, several aïstopod characters can also be seen, including a lack of sculpturing on the dentary and a reduced number of recurved, weakly socketed teeth. The anatomy of A. longidentatum corroborates recent phylogenetic work which has placed the origin of aïstopods within the Devonian fin-to-limb transition but preserves a mosaic of characteristics suggesting an even earlier divergence. The presence of an aïstopod in the Joggins fauna expands the taxonomic diversity of the Joggins fauna and suggests that Joggins may preserve a more typical Carboniferous fauna than previously thought.

Terlinguachelys fischbecki, a new genus and species of sea turtle (Chelonioidea: Protostegidae) from the Upper Cretaceous of Texas

2004 ◽  
Vol 78 (6) ◽  
pp. 1163-1178 ◽  
Author(s):  
Thomas M. Lehman ◽  
Susan L. Tomlinson
Keyword(s):  
National Park ◽  
Upper Cretaceous ◽  
New Genus ◽  
Sea Turtles ◽  
Sea Turtle ◽  
Unique Combination ◽  
New Genus And Species ◽  
Big Bend National Park ◽  
Big Bend ◽  
Lower Jaw

Remains of a large sea turtle, Terlinguachelys fischbecki n. gen. and sp., were recovered from paralic deposits of the Upper Cretaceous (Campanian) Aguja Formation in Big Bend National Park, Texas. T. fischbecki is a primitive protostegid that retains a constricted humerus, well ossified plastron and costals, prominent retroarticular process on the lower jaw, and long slender femora; however, it has some features, such as a prominent tubercle at the base of the scapular acromion process, found elsewhere only in derived leatherback sea turtles. The unique combination of primitive and derived traits in T. fischbecki illustrates further diversity among Cretaceous sea turtles and another case of parallelism common in sea turtle phylogeny.

scholarly journals Mexiterpes Sabinus, New Genus and New Species, a Mexican Troglobite (Diplopoda: Trichopetalidae)

1963 ◽  
Vol 70 (4) ◽  
pp. 235-239
Author(s):  
Nell B. Causey
Keyword(s):  
New Species ◽  
Nova Scotia ◽  
New Genus ◽  
Additional Species ◽  
The Family

This troglobitic milliped is of unusual interest because it is the type of a new genus and the first Mexican record of the family Trichopetalidae, which previously has been known from Nova Scotia to Louisiana, Oklahoma, and Colorado. If the genus has undergone speciation as related genera have, then additional species and subspecies will be found in other Mexican caves. Other millipeds from Mexican caves have been described by R. V. Chamberlin (1942).I am indebted to the members of the Texas Speleological Survey for the specimen from which this species was described.

A New Genus and Species of Chalcid (Hymenoptera: Encyrtidae)

1961 ◽  
Vol 93 (6) ◽  
pp. 494-496 ◽  
Author(s):  
C. D. F. Miller
Keyword(s):  
New Species ◽  
Nova Scotia ◽  
Type Species ◽  
New Genus ◽  
New Genus And Species ◽  
Alnus Crispa ◽  
Lake Region

In July, 1959 I reared a polyembryonic encyrtid from a species of Lithocolletis attacking Alnus crispa (Ait.) Pursh in the lake region around Ohio, Nova Scotia. It represents a species and genus new to science.Gibberella, new genusType species: Gibberella scutellata Miller, new species.

Acritarchs and microfossils from the Mesoproterozoic Bangemall Group, northwestern Australia

1999 ◽  
Vol 73 (5) ◽  
pp. 744-764 ◽  
Author(s):  
Roger Buick ◽  
Andrew H. Knoll
Keyword(s):  
New Genus ◽  
Taxonomic Diversity ◽  
Three Dimensions ◽  
Benthic Habitats ◽  
Thin Walls ◽  
Large Size ◽  
Numerical Abundance ◽  
Northwestern Australia ◽  
Shallow Subtidal ◽  
The Common

Three microfossil assemblages occur in the Mesoproterozoic Bangemall Group (1625-1000 Ma) of northwestern Australia, each occupying a different environmental and taphonomic setting. In peritidal environments, benthic prokaryotic filaments and spheroids of matting habit and small size were permineralized by early diagenetic silicification of stromatolitic carbonates. In shallow subtidal environments, benthic filaments of large size and nonmatting habit and planktonic sphaeromorph acritarchs with thin walls and moderate dimensions were compressed in mildly kerogenous shale. In deeper subtidal environments, planktonic megasphaeromorph acritarchs with thick walls were initially entombed in concretionary nodules in highly kerogenous shale and then permineralized by silica during later diagenesis. Taxonomic diversity and numerical abundance evidently decrease offshore. The three assemblages have typical Mesoproterozoic aspects: peritidal benthic habitats were dominated by Siphonophycus-Sphaerophycus-Eosynechococcus-Myxococcoides-Palaeopleurocapsa, shallow subtidal settings were occupied by Siphonophycus-Leiosphaeridia-Pterospermopsimorpha-Satka, and offshore plankton consisted solely of very large chuarid acritarchs. Because of its taphonomic restriction to mid-intertidal stromatolites, the peritidal assemblage can be equated in microenvironment with a similar assemblage in the Neoproterozoic Draken Conglomerate, suggesting that ecological stasis at the community level can last for intervals up to 900 million years. In the deeper subtidal assemblage, the common chuarid has an unusual mode of preservation, in three dimensions in early diagenetic concretions, revealing that it possesses a thick multilamellate wall. Because of this distinctive ultrastructure, the new genus Crassicorium is erected for these fossils, which are among the oldest indubitable eukaryotes. Very large (34-55 μm in diameter) filaments from shallow subtidal habitats are assigned to the emended species Siphonophycus punctatum.

scholarly journals IX.-On the skull and dentition of paraceratherium bugtiense: a genus of aberrant rhinoceroses from the lower Miocene deposits of Dera Bugti

1924 ◽  
Vol 212 (391-401) ◽  
pp. 369-394 ◽  
Keyword(s):  
New Genus ◽  
Posterior Part ◽  
Peculiar Feature ◽  
Lower Miocene ◽  
Lower Jaw ◽  
Lower Incisors

In 1911 a preliminary notice was published of a rhinocerotine lower jaw from the Bugti deposits of Baluchistan. This specimen shows a very peculiar feature of the front teeth, which instead of being procumbent, or even upturned, as in other rhinoceroses, are formed into a pair of downwardly turned tusks. On the strength of this well-marked character a new genus Paraceratherium was formed for the species. The posterior part of the lower jaw and loose upper and lower teeth had already been discovered in the same locality by Dr. Pilgrim, who, being without the anterior parts of the jaw, described the form as Aceratherium bugtiense . The same investigator had already described some curious teeth, which he had found lying seperately, as possible incisors of a skull which he named Bugtitherium grandincisivum, an animal which is possibly an Entelodont, but is still insufficiently known. These teeth are now known to be the lower incisors of Paraceratherium .

A new pachypleurosaur (Reptilia: Sauropterygia) from the Middle Triassic of Monte San Giorgio, Switzerland

1989 ◽  
Vol 323 (1212) ◽  
pp. 1-73 ◽  
Keyword(s):  
New Genus ◽  
Middle Triassic ◽  
Cladistic Analysis ◽  
Morphological Description ◽  
New Genus And Species ◽  
Lower Jaw ◽  
Jaw Mechanics ◽  
The Status ◽  
Mode Of Life ◽  
Aquatic Mode

Pachypleurosaur material from the Middle Triassic ‘ Grenzbitumen’-horizon (Anis-Ladin boundary) of Monte San Giorgio, Kanton Tessin, Switzerland, is described as a new genus and species, Serpianosaurus mirigiolensis .A detailed morphological description is followed by a quantitative analysis. The taxon differs from other pachypleurosaurids primarily by its relatively large skull and its straight lower jaw. Rib pachyostosis is absent. In most characters the taxon remains plesiomorphous with respect to other pachypleurosaurs from the Middle Triassic deposits of Monte San Giorgio, which accords well with its early stratigraphic occurrence at that locality. Sexual dimorphism is expressed by the size and shape of the humerus. A cladistic analysis shows the Pachypleurosauridae to constitute the sistergroup of all other Sauropterygia. The Sauropterygia and the Placodontia together form a monophyletic group, the Euryapsida, which is subordinated to the Diapsida and to the Neodiapsida, but which is classifed outside the archosauromorph-lepidosauromorph dichotomy within the Neodiapsida. A concluding paragraph discusses the status of the pachypleurosaurs within the Sauropterygia. Skull structure, and jaw mechanics in particular, suggest a relatively plesiomorph position of pachypleurosaurs within the Sauropterygia. Their adaptation to an aquatic mode of life was not carried to the degree observed in other sauropterygians, and the ability for rapid and deep dives seems to have been limited by middle-ear structure.

scholarly journals A new genus of Devonian tetrapod from North-East Greenland, with new information on the lower jaw of Ichthyostega

Palaeontology ◽  
2012 ◽  
Vol 55 (1) ◽  
pp. 73-86 ◽  
Author(s):  
JENNIFER A. CLACK ◽  
PER E. AHLBERG ◽  
HENNING BLOM ◽  
SARAH M. FINNEY
Keyword(s):  
New Genus ◽  
East Greenland ◽  
North East ◽  
Lower Jaw ◽  
New Information

A new genus and species of anthracosaur amphibian from the Lower Carboniferous of Scotland and the status of Pholidogaster pisciformis Huxley

1975 ◽  
Vol 269 (900) ◽  
pp. 581-637 ◽  
Keyword(s):  
New Genus ◽  
New Genus And Species ◽  
Lower Carboniferous ◽  
Lower Jaw ◽  
The Family ◽  
Close Relationship ◽  
The Status ◽  
Coal Measures ◽  
Composite Restoration

The isolated skull of a Lower Carboniferous anthracosaur labyrinthodont from the Midlothian coalfield was formerly but erroneously attributed to Pholidogaster pisciformis . It is now redescribed after ‘Airbrasive’ development as the holotype of a new genus and species. The anthracosaur agrees in a number of diagnostic cranial characters with the embolomerous forms of the Coal Measures but other characters, particularly those of the braincase and lower jaw, suggest relationship to the Seymouriamorpha. Its cranial anatomy could well be antecedent to that of both these groups and the sparse evidence available suggests close relationship to the American Mississippian anthracosaur Proterogyrinus . A new classification of the Batrachosauria is presented with a major subdivision into Anthracosauria and Seymouriamorpha. The former group comprises the newly proposed infraorder Herpetospondyli to include the Lower Carboniferous forms, together with the infraorders Embolomeri and Gephyrostegoidea. It is concluded that while no batrachosaur with an otic notch could be a reptile ancestor a primitive ‘notchless’ anthracosaur could be. The cranial anatomy of Pholidogaster pisciformis is then redescribed, after complete ‘Airbrasive’ preparation of the holotype skull. The holotype, like the anthracosaur, comes from the Gilmerton Ironstone of the Edinburgh region, but the earlier holotype skull of Otocratia modesta , long considered to be an ichthyostegid, is also attributed to Pholidogaster . After redescription of ‘ Otocratia ' a composite restoration of the Pholidogaster skull is presented. The nature of the dermal ornament, the post-parietal-supratemporal suture, the absence of tabular horns and the nature of the post-cranial skeleton all demonstrate that Pholidogaster is an early temnospondyl labyrinthodont in no way closely related to anthracosaurs. It is closely similar to the American Mississippian form Greererpeton burkemorani Romer, notably in the presence of large premaxillary fangs and the absence of otic notch and intertemporal. Both may be attributed to the family Colosteidae. It is concluded that there is no strong evidence of close relationship between the colosteids and the Devonian ichthyostegids.

A New Primate from the Middle Eocene of Myanmar and the Asian Early Origin of Anthropoids

Science ◽  
1999 ◽  
Vol 286 (5439) ◽  
pp. 528-530 ◽  
Author(s):  
J.-J. Jaeger ◽  
Tin Thein ◽  
M. Benammi ◽  
Y. Chaimanee ◽  
Aung Naing Soe ◽  
...  
Keyword(s):  
New Genus ◽  
Middle Eocene ◽  
Sister Group ◽  
New Genus And Species ◽  
Asian Origin ◽  
Anthropoid Primate ◽  
Lower Jaw ◽  
The Family ◽  
Early Origin

A new genus and species of anthropoid primate,Bahinia pondaungensis gen. et sp. nov., is described from the Yashe Kyitchaung locality in the Late Middle Eocene Pondaung Formation (Myanmar). It is related to Eosimias, but it is represented by more complete remains, including upper dentition with associated lower jaw fragment. It is interpreted as a new representative of the family Eosimiidae, which corresponds to the sister group of the Amphipithecidae and of all other anthropoids. Eosimiidae are now recorded from three distinct Middle Eocene localities in Asia, giving support to the hypothesis of an Asian origin of anthropoids.

The last Labyrinthodont? A new brachyopoid (Amphibia, Temnospondyli) from the early Jurassic Evergreen formation of Queensland, Australia

1983 ◽  
Vol 303 (1113) ◽  
pp. 1-62 ◽  
Keyword(s):  
New Genus ◽  
Neck Region ◽  
Early Jurassic ◽  
Postcranial Skeleton ◽  
New Genus And Species ◽  
Large Size ◽  
Lower Jaw ◽  
The Family ◽  
The Right ◽  
Southeast Queensland

Remains of a fossil amphibian have been recovered from an ironstone layer in the Upper Evergreen Formation, dated as late Liassic, of southeast Queensland. Extraction of the skeleton from the very hard matrix has presented a number of problem s which are discussed. The find is an almost complete skull and mandible connected to an articulated postcranial skeleton which is missing only some ribs, the right hind leg and the distal portions of the other limbs and tail. The remains are those of a temnospondyl labyrinthodont described as a new genus and species of the family Chigutisauridae. The new form is notable for its very large size (total length estimated to be in excess of 2.5 m), relatively large marginal dentition, with unique lance-shaped tooth tips, the presence of minute denticles associated with the palate and mandible, a well developed atlas showing a strong link with the axis, neorhachitomous vertebrae that lack ossified pleurocentra and have low, heavily built neural spines, a neck region and a narrow dermal pectoral girdle associated with unreduced limbs. The discovery of this chigutisaur provides the first unequivocal evidence that labyrinthodonts survived beyond the end of the Triassic. T he status of two previously described doubtful Jurassic forms is reviewed. Austropelor Longman, 1941, from the Early Jurassic Marburg Sandstone of southeast Queensland, is confirmed as a fragm ent of temnospondyl lower jaw , probably attributable to the superfamily Brachyopoidea, and there is no longer any reason to consider the earlier suggestion that it is a reworked Triassic fossil. Cyrtura Jaekel, 1904, from the Late Jurassic Solnhofen Shale of Germany, is considered not to be a labyrinthodont, but its exact relationships are uncertain. The unsatisfactory nature of the higher taxonomy of the Temnospondyli is noted. The superfamily Brachyopoidea is reviewed and the family Kourerpetontidae is removed from it, membership of the superfamily thereby being restricted to the Brachyopidae (Late Permian to Middle Triassic) and Chigutisauridae (Early Triassic to Early Jurassic). Diagnoses for the superfamily and its two included families are provided. The relationships of the better characterized members of the two families are examined and a phylogeny based on shared derived character states is proposed. The analysis of relationships indicates that Brachyops allos Howie, 1972 shares few of the characters diagnostic of the type of Brachyops (B. laticeps Owen, 1855), and a new genus is proposed. The diversity of Australia’s brachyopoids, including the presence of the most primitive and earliest-known members of each of the included families, suggests that the superfamily originated in Australia.

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