Aspects of the postcranial skeleton of the Lower Permian lungfish, Gnathorhiza

1989 ◽  
Vol 63 (6) ◽  
pp. 919-930 ◽  
Author(s):  
Walter W. Dalquest ◽  
M. John Kocurko ◽  
John V. Grimes
Keyword(s):  
Axial Skeleton ◽  
Lower Permian ◽  
Fish Scales ◽  
Early Permian ◽  
Postcranial Skeleton ◽  
Caudal Fin ◽  
North Central ◽  
New Information ◽  
Central Texas ◽  
Median Fins

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.

Crustacean-bearing continental deposits in the Petrolia Formation (Leonardian Series, Lower Permian) of north-central Texas

2002 ◽  
Vol 76 (3) ◽  
pp. 486-494 ◽  
Author(s):  
Nicholas Hotton ◽  
Rodney M. Feldmann ◽  
Robert W. Hook ◽  
William A. Dimichele
Keyword(s):  
New Species ◽  
South America ◽  
South Dakota ◽  
Suspended Load ◽  
Lower Permian ◽  
Early Permian ◽  
North Central ◽  
Upper Carboniferous ◽  
Continental Deposits ◽  
Central Texas

Numerous pygocephalomorph crustaceans occur with conchostracans, plants, fishes, amphibians, and amniotes in the Petrolia Formation (Leonardian Series, Lower Permian) of Baylor and Archer counties, Texas. Two pygocephalomorph species are represented; Mamayocaris serendipitous, new species, by hundreds of specimens that appear to be molted exoskeletons, and Paulocaris schrami, new species, by only a few specimens. Mamayocaris has been reported previously from the Lower Permian of Texas and South Dakota and the Upper Carboniferous of Illinois; Paulocaris was previously known only from South America. Associated plant assemblages are dominated by conifers accompanied by other Early Permian and some Late Carboniferous elements. Accompanying vertebrate remains include aquatic to fully terrestrial forms with close taxonomic ties to genera or families recorded in Upper Carboniferous deposits. The fossils are preserved in local deposits of thin (<2 cm), lenticular to nodular beds of limestone and thin (<15 cm) intervals of dark-gray claystone. These deposits accumulated in abandoned, standing-water segments of suspended-load fluvial channels. The archaic nature of these plant and animal assemblages supports previous interpretations that the Permian Petrolia Formation contains paleoenvironmentally isolated biotic elements characteristic of the Carboniferous and underscores prior depictions of the assemblages as relictual.

Natural history of a plant trait: branch-system abscission in Paleozoic conifers and its environmental, autecological, and ecosystem implications in a fire-prone world

Paleobiology ◽  
10.1666/12030 ◽  
2013 ◽  
Vol 39 (2) ◽  
pp. 235-252 ◽  
Author(s):  
Cindy V. Looy
Keyword(s):  
Fire Regime ◽  
Climatic Conditions ◽  
Early Permian ◽  
North Central ◽  
Seasonally Dry ◽  
Plant Trait ◽  
Branch System ◽  
Central Texas ◽  
History Of ◽  
Biotic Disturbance

Within conifers, active abscission of complete penultimate branch systems is not common and has been described mainly from juveniles. Here I present evidence for the abscission of penultimate branch systems within early so-called walchian conifers—trees with a plagiotropic branching pattern. The specimens studied originate from a middle Early Permian gymnosperm-dominated flora within the middle Clear Fork Group of north-central Texas. Complete branch systems of three walchian conifer morphotypes are preserved; all have pronounced swellings and smooth separation faces at their bases. The source plants grew in a streamside habitat under seasonally dry climatic conditions. The evolution of active branch abscission appears to correspond to an increase in the size of conifers, and this combination potentially contributed to the restructuring of conifer-rich late Paleozoic landscapes. Moreover, trees shedding branch systems and producing abundant litter have the potential to affect the fire regime, which is a factor of evolutionary importance because wildfires must have been a source of frequent biotic disturbance throughout the hyperoxic Early Permian.

Late Early Permian continental ichnofauna from Lake Kemp, north-central Texas, USA

2011 ◽  
Vol 308 (3-4) ◽  
pp. 395-404 ◽  
Author(s):  
Spencer G. Lucas ◽  
Sebastian Voigt ◽  
Allan J Lerner ◽  
W. John Nelson
Keyword(s):  
Early Permian ◽  
North Central ◽  
North Central Texas ◽  
Central Texas

Seymouria sanjuanensis (Amphibia, Batrachosauria) from the Lower Permian Cutler Formation of north-central New Mexico and the occurrence of sexual dimorphism in that genus questioned

1987 ◽  
Vol 24 (9) ◽  
pp. 1769-1784 ◽  
Author(s):  
David S Berman ◽  
Robert R. Reisz ◽  
David A. Eberth
Keyword(s):  
New Mexico ◽  
Sexual Dimorphism ◽  
Axial Skeleton ◽  
Lower Permian ◽  
Satisfactory Explanation ◽  
North Central ◽  
Haemal Arch ◽  
Single Block ◽  
Definition Of ◽  
Maxillary Dentition

Six specimens of the amphibian Seymouria, preserved in a single block of matrix from the Lower Permian Cutler Formation of north-central New Mexico, are described and referred to Seymouria sanjuanensis Vaughn. They are the only Seymouria specimens known from New Mexico and provide a more extensive definition of the species. It is interpreted that the specimens from New Mexico were collected from an early to middle Wolfcampian horizon and therefore represent the earliest known members of the genus. Evidence is presented that challenges previous explanations for the variability of several features of the skull and axial skeleton in specimens of Seymouria baylorensis and S. sanjuanensis as an indication of sexual dimorphism. Differences in the number of maxillary teeth, depth of the maxilla, and development of the maxillary dentition, particularly in the "canine" region, are interpreted as closely related morphological trends in Seymouria. Although no satisfactory explanation is offered for differences in the serial position of the first haemal arch and in the interorbital breadth, sexual dimorphism is considered very unlikely.

New information on the pectoral girdle and vertebral column in Lupeosaurus (Reptilia, Pelycosauria)

1989 ◽  
Vol 26 (7) ◽  
pp. 1343-1349 ◽  
Author(s):  
Stuart S. Sumida
Keyword(s):  
Cross Section ◽  
Vertebral Column ◽  
Cervical Vertebrae ◽  
Lower Permian ◽  
Pectoral Girdle ◽  
Postcranial Skeleton ◽  
Posterior Edge ◽  
Articular Facet ◽  
New Information

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.

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