scholarly journals A small caseid synapsid, Arisierpeton simplex gen. et sp. nov., from the early Permian of Oklahoma, with a discussion of synapsid diversity at the classic Richards Spur locality

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6615 ◽  
Author(s):  
Robert R. Reisz

The fossil record of caseids, a clade of faunivorous to large herbivorous Permian synapsids, is unusual in having a poorly documented history. Although Kungurian caseids are common in the well-known continental deposits of North America, and the fossil record of the group extends into the middle Permian (Guadalupian), with the presence of the large caseid Ennatosaurus in the Mezen Basin faunal assemblage, only two other occurrences are known in older Permian age sediments. One is an undescribed caseid from the Bromacker Quarry in Germany, and the second is Oromycter from the lower Permian of Richards Spur, Oklahoma. The former is known from several articulated skeletons, but the latter is known only from a handful of skeletal elements, including elements of the snout and lower jaw, some phalanges, and a few vertebrae. Here the fragmentary tooth bearing elements and dorsal vertebrae of another small caseid from Richards Spur are described, with a discussion of its significance in the context of caseid evolution, and the continuously expanding faunal list and taxic diversity at this locality.

2017 ◽  
Vol 284 (1852) ◽  
pp. 20170231 ◽  
Author(s):  
Neil Brocklehurst ◽  
Michael O. Day ◽  
Bruce S. Rubidge ◽  
Jörg Fröbisch

The terrestrial vertebrate fauna underwent a substantial change in composition between the lower and middle Permian. The lower Permian fauna was characterized by diverse and abundant amphibians and pelycosaurian-grade synapsids. During the middle Permian, a therapsid-dominated fauna, containing a diverse array of parareptiles and a considerably reduced richness of amphibians, replaced this. However, it is debated whether the transition is a genuine event, accompanied by a mass extinction, or whether it is merely an artefact of the shift in sampling from the palaeoequatorial latitudes to the palaeotemperate latitudes. Here we use an up-to-date biostratigraphy and incorporate recent discoveries to thoroughly review the Permian tetrapod fossil record. We suggest that the faunal transition represents a genuine event; the lower Permian temperate faunas are more similar to lower Permian equatorial faunas than middle Permian temperate faunas. The transition was not consistent across latitudes; the turnover occurred more rapidly in Russia, but was delayed in North America. The argument that the mass extinction is an artefact of a latitudinal biodiversity gradient and a shift in sampling localities is rejected: sampling correction demonstrates an inverse latitudinal biodiversity gradient was prevalent during the Permian, with peak diversity in the temperate latitudes.


2011 ◽  
Vol 278 (1725) ◽  
pp. 3731-3737 ◽  
Author(s):  
Robert R. Reisz ◽  
Sean P. Modesto ◽  
Diane M. Scott

The initial stages of evolution of Diapsida (the large clade that includes not only snakes, lizards, crocodiles and birds, but also dinosaurs and numerous other extinct taxa) is clouded by an exceedingly poor Palaeozoic fossil record. Previous studies had indicated a 38 Myr gap between the first appearance of the oldest diapsid clade (Araeoscelidia), ca 304 million years ago (Ma), and that of its sister group in the Middle Permian ( ca 266 Ma). Two new reptile skulls from the Richards Spur locality, Lower Permian of Oklahoma, represent a new diapsid reptile: Orovenator mayorum n. gen. et sp. A phylogenetic analysis identifies O. mayorum as the oldest and most basal member of the araeoscelidian sister group. As Richards Spur has recently been dated to 289 Ma, the new diapsid neatly spans the above gap by appearing 15 Myr after the origin of Diapsida. The presence of O. mayorum at Richards Spur, which records a diverse upland fauna, suggests that initial stages in the evolution of non-araeoscelidian diapsids may have been tied to upland environments. This hypothesis is consonant with the overall scant record for non-araeoscelidian diapsids during the Permian Period, when the well-known terrestrial vertebrate communities are preserved almost exclusively in lowland deltaic, flood plain and lacustrine sedimentary rocks.


2003 ◽  
Vol 77 (2) ◽  
pp. 389-392 ◽  
Author(s):  
Graciela Piñeiro ◽  
Mariano Verde ◽  
Martín Ubilla ◽  
Jorge Ferigolo

In their monograph Review of the Pelycosauria, Romer and Price (1940), proposed that the earliest synapsids (“pelycosaurs”) were cosmopolitan, despite the observation that amniotes appeared to be restricted to the paleotropics during the Late Carboniferous and Early Permian (290–282 Ma). Romer and Price (1940) accounted for the scarcity of terrestrial tetrapods, including “pelycosaurs,” in Lower Permian beds elsewhere to the absence of coeval continental deposits beyond North America and Europe. Indeed, most workers recognized a geographical and temporal gap between Permo-Carboniferous “pelycosaurs” and therapsid synapsids. Recent research has confirmed that varanopid and caseid “pelycosaurs” were components of therapsid-dominated Late Permian faunas preserved in Russia and South-Africa (Tatarinov and Eremina, 1975; Reisz, 1986; Reisz et al., 1998; Reisz and Berman, 2001).


2021 ◽  
pp. 1-15
Author(s):  
Thomas M. Cullen ◽  
Lindsay Zanno ◽  
Derek W. Larson ◽  
Erinn Todd ◽  
Philip J. Currie ◽  
...  

The Dinosaur Park Formation (DPF) of Alberta, Canada, has produced one of the most diverse dinosaur faunas, with the record favouring large-bodied taxa, in terms of number and completeness of skeletons. Although small theropods are well documented in the assemblage, taxonomic assessments are frequently based on isolated, fragmentary skeletal elements. Here we reassess DPF theropod biodiversity using morphological comparisons, high-resolution biostratigraphy, and morphometric analyses, with a focus on specimens/taxa originally described from isolated material. In addition to clarifying taxic diversity, we test whether DPF theropods preserve faunal zonation/turnover patterns similar to those previously documented for megaherbivores. Frontal bones referred to a therizinosaur (cf. Erlikosaurus), representing among the only skeletal record of the group from the Campanian–Maastrichtian (83–66 Ma) fossil record of North America, plot most closely to troodontids in morphospace, distinct from non-DPF therizinosaurs, a placement supported by a suite of troodontid anatomical frontal characters. Postcranial material referred to cf. Erlikosaurus in North America is also reviewed and found most similar in morphology to caenagnathids, rather than therizinosaurs. Among troodontids, we document considerable morphospace and biostratigraphic overlap between Stenonychosaurus and the recently described Latenivenatrix, as well as a variable distribution of putatively autapomorphic characters, calling the validity of the latter taxon into question. Biostratigraphically, there are no broad-scale patterns of faunal zonation similar to those previously documented in ornithischians from the DPF, with many theropods ranging throughout much of the formation and overlapping extensively, possibly reflecting a lack of sensitivity to environmental changes, or other cryptic ecological or evolutionary factors.


1997 ◽  
Vol 67 (1) ◽  
pp. 9-70 ◽  
Author(s):  
H.-P. Schultze ◽  
J. Chorn

The lungfish Sagenodus is a widespread Permo-Carboniferous genus found in Europe and North America. Important localities in the U.S.A. include Middle Pennsylvanian coals near Linton, Ohio, Upper Pennsylvanian deposits near Robinson and Hamilton, Kansas, and Peoria, Illinois; Lower Permian sediments near Cameron, Ohio; and Lower Permian “Red Beds” of Texas and Oklahoma. At least three species of Sagenodus were present in North America S. copeanus, S. periprion, S. serratus). S. ohiensis is represented solely by one skull. Knowledge of the osteology of Sagenodus is enhanced by the study of well-preserved but disassociated elements from Robinson, Kansas (S. copeanus) and Little Bitter Creek, Texas (S. serratus). The orbital series is now known to be comprised of six elements and the sensory canal system is more complex than previously realized. The only known articulated skeleton of this genus, from Hamilton Quarry, Kansas, permits a restoration of the entire animal including the median fins. The dorsal and anal fins are not separate; there is instead, a continuous fin around the caudal end of the body, as found in other post-Devonian lungfishes. Sagenodus is structurally intermediate between more primitive Devonian dipnoans and post-Paleozoic lungfishes. Evident trends can be seen in the reduction of bone (both number of bones and degree of ossification), the loss of cosmine, the nature of the scales, the structure and histology of tooth plates, and the configuration of the median fins. Sagenodus is a member of a euryhaline faunal assemblage that can be found from shallow marine to freshwater deposits.


1995 ◽  
Vol 69 (5) ◽  
pp. 805-812 ◽  
Author(s):  
Calvin H. Stevens

The discovery of a new locality yielding giant Guadalupian (Lower Permian) fusulinids in east-central Alaska extends the range of these forms much farther north than previously known, and into a tectonostratigraphic terrane from which they previously had not been reported. The number of areas from which giant parafusulinids are known in North America is thus raised to eight. Three of these localities are in rocks that previously had been referred to the allochthonous McCloud belt arc, and one, West Texas, is known to have been part of Paleozoic North America. Comparison of species from all areas suggests that there are two closely related species groups: one represented in Texas and Coahuila, and the other represented in Sonora, northern California, northeastern Washington, southern and northern British Columbia, Alaska, and apparently in Texas. These groups may differ because they are of slightly different ages or because interchange between the faunas of Texas–Coahuila area and the other regions was somewhat inhibited during the Early Permian.


1993 ◽  
Vol 67 (6) ◽  
pp. 935-945 ◽  
Author(s):  
Edward C. Wilson ◽  
Ralph L. Langenheim

Rugose and tabulate corals from the Lower Permian (Wolfcampian) part of the Bird Spring Group in Arrow Canyon, Arrow Canyon Range, Clark County, Nevada, comprise eight species in eight genera. Stylastraea rowetti n. sp. is the first unequivocal record of this genus west of Texas in North America. Heritschiella girtyi, the only endemic North American waagenophyllid genus and species, is recorded outside Kansas for the first time. Paraheritschioides stevensi formerly was known only from northern California. The other species also occur elsewhere in the Permian of Nevada and nearby. This southeast Nevada shelf area has the first known intermixture of corals from the Durhaminid Coral Province and subprovinces of far western North America and the Cyathaxonid Coral Province of middle and southwestern North America.


2001 ◽  
Vol 38 (5) ◽  
pp. 803-812 ◽  
Author(s):  
David S Berman ◽  
Robert R Reisz ◽  
Thomas Martens ◽  
Amy C Henrici

A new species of the sphenacodontid synapsid Dimetrodon, D. teutonis, is described on the basis of a single, adult specimen consisting of a large portion of the presacral vertebral column. The holotype was collected from the Lower Permian Tambach Formation, lowermost formational unit of the Upper Rotliegend, of the Bromacker quarry locality in the midregion of the Thuringian Forest near Gotha, central Germany. This is the first record of the genus outside of North America and, therefore, provides not only additional biological evidence of a continuous Euramerican landmass during the Early Permian, but also the absence of any major physical or biological barrier to faunal interchange of terrestrial vertebrates. An estimated weight of 14 kg for D. teutonis is half that of the smallest, previously recognized species, D. natalis. Sphenacodontid phylogeny indicates that the diminutive size of D. teutonis represents an autapomorphy and is in general accord with the absence of large-sized, basal synapsid predators at this truly terrestrial upland locality. It is speculated that the diminutive size of D. teutonis was probably an adaptation to a truly terrestrial, relatively uplands existence like that represented by the Bromacker locality. Here it subsisted on small vertebrates (and possibly large invertebrates) of the Bromacker assemblage, in which the dominant members in both size and abundance were herbivorous diadectids, and it was unlikely to encounter large predators.


Fossil Record ◽  
2013 ◽  
Vol 16 (2) ◽  
pp. 229-243 ◽  
Author(s):  
J. A. Dunlop ◽  
R. Rößler

A new trigonotarbid (Arachnida: Trigonotarbida) is described as <i>Permotarbus schuberti</i> n. gen., n. sp. from the Early Permian Petrified Forest (Rotliegend) of Chemnitz in Saxony (Germany). At ca. 290 Ma it represents the youngest record of this extinct arachnid order discovered to date. Its familial affinities are uncertain, but may lie close to the Aphantomartidae. The distribution of the trigonotarbid genera through time is summarised, together with a list of their seventy-seven fossil-yielding localities. Together they offer a broad overview of the group's fossil record, which is heavily biased towards the Moscovian Stage (ca. 307–312 Ma) of the Late Carboniferous in Europe and North America. This is due in no small part to numerous localities associated with coal mining districts, and trigonotarbids are found less frequently after this stage. While it is tempting to associate this with biological events – such as a putative "Carboniferous Rainforest Collapse" dating to ca. 305 Ma – it is difficult to differentiate the effects of genuine extinction patterns from artefacts caused by fewer appropriate localities in the economically less relevant latest Carboniferous and Early Permian strata. Nevertheless, trigonotarbids became extinct at some point after the Early Permian and loss of the Coal Measures forests remains one of the most likely possible causes. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.201300012" target="_blank">10.1002/mmng.201300012</a>


Author(s):  
Frederik SPINDLER

ABSTRACTThe holotypic isolated maxilla of the early sphenacodontian Haptodus grandis from the Cisuralian of England is revisited. A unique character combination includes haptodontine-grade traits like less specialised teeth and a high number of precanines, but at the same time a shortened lacrimal that is separated from the naris, which is strongly diagnostic of Sphenacodontoidea. As the specimen cannot be assigned to any known taxon, the new taxon Hypselohaptodus grandis gen. nov. is proposed. Comparison with other sphenacodontians reveals a mosaic distribution of maxillary features, most significantly regarding the precanine region. Preliminary character histories preclude Hypselohaptodus from Sphenacodontidae, but suggest a haptodontine-grade or basal therapsid position. The latter hypothesis is substantiated by an ecological model of episodic wet phases in an overall trend of aridification throughout the Permian, to explain the rareness of non-sphenacodontid sphenacodontians in the fossil record. Also from the early Permian of England, an isolated dentary has previously been assigned to Ophiacodon, but can be shown to be either a sphenacodontian, possibly affiliated with Hypselohaptodus, or a robust, Stereorhachis-like ophiacodontid. The absence of Ophiacodon in the intramontaneous Permian basis of Europe is explained by a narrow environmental tolerance range requiring limnic connection with lowland basins.


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