New information on the postcranial skeleton of the Thalassodrominae (Pterosauria, Pterodactyloidea, Tapejaridae)

2017 ◽  
Vol 30 (8) ◽  
pp. 1139-1149 ◽  
Author(s):  
Richard Buchmann ◽  
Taissa Rodrigues ◽  
Sabrina Polegario ◽  
Alexander W. A. Kellner
1989 ◽  
Vol 63 (6) ◽  
pp. 919-930 ◽  
Author(s):  
Walter W. Dalquest ◽  
M. John Kocurko ◽  
John V. Grimes

A newly discovered locality of aestivation burrow casts containing the lungfish, Gnathorhiza serrata, is reported from the early Permian Arroyo Formation of Wilbarger County, north-central Texas. Remains preserved in the burrow casts provide sections of mummified Gnathorhiza and new information about the postcranial skeleton of this fish. Scales of Gnathorhiza resemble those of the modern lungfishes such as Lepidosiren in their microanatomy. No traces of paddle-like pectoral or pelvic fins were found and paired fins of Gnathorhiza may have resembled those of Lepidosiren. The axial skeleton and median fins of Gnathorhiza seem to resemble those of Lepidosiren except that the tail area and caudal fin of Gnathorhiza were stout and strong rather than slender and tapering. Gnathorhiza, which aestivated tail-down in its burrow, may have required a stout tail for support.


1989 ◽  
Vol 26 (7) ◽  
pp. 1343-1349 ◽  
Author(s):  
Stuart S. Sumida

UCLA VP 1651, a new specimen from the Lower Permian Admiral Formation of Archer County, Texas, provides information on heretofore unknown portions of the postcranial skeleton of the large pelycosaur Lupeosaurus. Presacral neural spines are elongate and have a subcircular cross section. Laterally directed tubercles are not present on any of the neural spines. Cervical vertebrae appear to have elongate neural spines and sharply keeled centra. Transverse processes are positioned relatively high above the bases of the centra through the length of axial column. The pattern of tilting of the neural spines is similar to that in the primitive edaphosaur Ianthasaurus hardestii. The proximal end of the first sacral rib contributes significantly to the intervertebral articular facet usually formed by the centra. The sacral ribs do not appear to fuse with one another distally. The ventral clavicular plate is greatly expanded anteriorly. The posterior edge of the subcoracoscapular fossa is very well defined. The available morphological information does not warrant a separate familial designation for the genus Lupeosaurus. Despite the lack of laterally directed tubercles of the neural spines, Lupeosaurus appears to be referrable to the Edaphosauridae. However, in the absence of cranial materials, this association must remain tentative. Although this description adds new information for only a restricted portion of the skeleton, it does appear to confirm the existence of a distinct, albeit rare, pelycosaur from the extensively studied fauna of the Lower Permian.


2015 ◽  
Vol 28 (7) ◽  
pp. 978-989 ◽  
Author(s):  
Ane Elise Branco Pavanatto ◽  
Rodrigo Temp Müller ◽  
Átila Augusto Stock Da-Rosa ◽  
Sérgio Dias-da-Silva

2011 ◽  
Vol 7 (6) ◽  
pp. 937-940 ◽  
Author(s):  
Borja Figueirido ◽  
Christine M. Janis

The extinct thylacine ( Thylacinus cynocephalus ) and the extant grey wolf ( Canis lupus ) are textbook examples of convergence between marsupials and placentals. Craniodental studies confirm the thylacine's carnivorous diet, but little attention has been paid to its postcranial skeleton, which would confirm or refute rare eyewitness reports of a more ambushing predatory mode than the pack-hunting pursuit mode of wolves and other large canids. Here we show that thylacines had the elbow morphology typical of an ambush predator, and propose that the ‘Tasmanian tiger’ vernacular name might be more apt than the ‘marsupial wolf’. The ‘ niche overlap hypothesis ’ with dingoes ( Canis lupus dingo ) as a main cause of thylacine extinction in mainland Australia is discussed in the light of this new information.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2177 ◽  
Author(s):  
Xin Cheng ◽  
Shunxing Jiang ◽  
Xiaolin Wang ◽  
Alexander W.A. Kellner

The Wukongopteridae is an important pterosaur group discovered from Yanliao Biota, because it combines character states seen in non-pterodactyloid and pterodactyloid pterosaurs. So far, the Wukongopteridae contains three genera:Wukongopterus,DarwinopterusandKunpengopterus; representing five species. Here we report on a new specimen, IVPP V 17959, that can be undoubtedly referred to the Wukongopteridae based on the presence of a confluent nasoantorbital fenestra, elongated cervical vertebrae (convergent with Pterodactyloidea) and a long tail enclosed by rod-like bony extensions of the zygapophyses. Traits distinguishing this new specimen from other wukongopterid pterosaurs include a premaxilla with a low ossified anterodorsal crest, a nasal bearing the most elongated process known in the Wukongopteridae, and a lacrimal that has a foramen in its middle portion. The new kind of premaxillary crest preserved in IVPP V 17959 suggests that the presence or absence of a premaxillary crest might be an interspecific feature within the Wukongopteridae. A phylogenetic analysis including all wukongopterid pterosaurs recovers IVPP V 17959 in a polytomy withWukongopterusand the species ofDarwinopterus, havingKunpengopterusin a more basal position. The postcranial skeleton of IVPP V 17959 has ontogenetically mature characteristics including a completely fused scapula and coracoid, fused proximal and distal carpal series, and an ossified extensor tendon process of the first wing phalanx, allowing its classification as ontogenetic stage five. Furthermore, the atlas and axis are separated in IVPP V 17959, which indicates that these two bones probably are not fused in skeletally mature wukongopterid individuals.


2000 ◽  
Vol 74 (6) ◽  
pp. 1191-1195 ◽  
Author(s):  
P. S. Spencer ◽  
M. S. Y. Lee

Although pareiasaurs are one of the most abundant and conspicuous elements of Late Permian terrestrial ecosystems, small individuals of these reptiles (either small species or juveniles of large species) are extremely rare. Until now, the smallest known pareiasaur is the type of the late, heavily armored form Anthodon (=Nanoparia) pricei (Bernard Price Institute of Palaeontological Research, Johannesburg 1/6), with a skull length of 10 cm and an inferred snout-vent length of approximately 50 cm. This is presumably an adult of a dwarf form, since all elements of the skull and postcranial skeleton are fully ossified, sutures are closed, and the dermal armor is more highly developed than in any other pareiasaur (Broom and Robinson, 1948; Brink, 1955; Findlay, 1970; Lee, 1997). A second and as yet undescribed specimen (Geological Survey, Pretoria CM86/544) is approximately the same size, being only very slightly larger (Lee, 1997). No other specimens of this taxon are known. An unnumbered humerus in the Amalitsky collection of the Palaeontological Institute, Moscow, is from a pareiasaur of similar size to the second specimen of A. pricei. However, this specimen is presumably a juvenile of a large form: the ends of the humerus are unossified, and the specimen comes from the North Dvina bone beds, which have yielded numerous specimens of the large pareiasaur Scutosaurus but no other pareiasaur taxon. Here, we re-evaluate a specimen originally described as a dicynodont tail, and later as a procolophonoid, and demonstrate that it is actually a juvenile of the pareiasaur Elginia mirabilis. It is also by far the smallest pareiasaur so far known, being approximately half the dimensions of the next smallest individual, the type specimen of Anthodon pricei. The newly recognized specimen provides new information on the ontogeny of pareiasaurs and the homology of some problematic skull elements.


2015 ◽  
Vol 28 (5) ◽  
pp. 666-679 ◽  
Author(s):  
Ya-Ming Wang ◽  
Jingmai K. O'Connor ◽  
Da-Qing Li ◽  
Hai-Lu You

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