No description available.

Tangasaurid eosuchians are represented by hundreds of specimens from the Permo-Triassic strata of Madagascar and Africa. The confusion surrounding the identification and anatomy of these reptiles is resolved by comparative anatomy and relative measurements, and three genera, Thadeosaurus, Tangasaurus and Hovasaurus, are described. Extensive growth series present a unique opportunity to study differences in growth strategies in two closely related Permian genera, one that was terrestrial (Thadeosaurus) and the other aquatic (Hovasaurus). The vertebrae of Youngina have a derived character state that indicates close relationship with the tangasaurids. A new genus and species of eosuchian, Acerosodontosaurus piveteaui, has a specialized feature in the carpus that is found in the Tangasauridae. The relationships between tangasaurids and other eosuchians are considered.

No description available.

Call number: LD2668 .T4 1965 L77 / Master of Science

No description available.

A succession of late Early through Medial Permian conodont faunas is documented for the first time from the calcareous, fine grained, quartzose sandstones of the Assistance and Trold Fiord Formations on northern Elles-mere Island, Northwest Territories. Of the taxa identified and described, one species and three subspecies are proposed as new. The taxa include, in chronological order: Neogondolella idahoensis subsp. indet., Neostrep-tognathodus prayi, Neogondolella idahoensis n.subsp. A, Anchignathodus minutus, Neogondolella serrata(?), N. n.sp. B, N. postserrata(?), N. bitteri n.subsp. C, and N. rosenkrantzi n.subsp. D. Numerous ramiform elements are also associated with Neogondolella idahoensis n.subsp. A. These elements may comprise part of a multielement Neogondolella apparatus or they may represent separate form species. In observation of their questionable status, a somewhat unsatisfactory dual taxonomy is proposed for these elements, and includes the following taxa: N. idahoensis n.subsp. A - Xanio-gnathus tortilis, N. idahoensis n.subsp. A - Ellisonia excavata, N. idahoensis n.subsp. A - Ellisonia tribulosa, and N. idahoensis n.subsp. A - Pri-oniodella decrescens. Statistical work on the abundant platform elements of N. idahoensis n.subsp. A provides evidence for minor 'evolutionary trends of increasing size and increasing number of denticles upsection. Comparison of these con-odonts with N. serrata.and N. postserrata from the Great Basin of SW USA suggests that the phylogenetic development of Permian Neogondolella followed an,, evolutionary path.more appropriate to punctuated equilibria than to phyletic gradualism. The conodont taxa indicate that the Assistance Formation is Upper Leonardian to Uppermost Roadian in age whereas the Trold Fiord Formation includes most of the Wordian.stage. These two formations have been separated into five subdivisions on the basis of both lithology. and the presence or absence of various biota 1 A sixth, subdivision is described for the Sabine Bay Formation which underlies the Assistance and where conodonts are apparently absent. Lithologic and biotic evidence (including trace fossils and mega- and microbiota) point to shallow, offshore marine conditions well within the photic zone and characterized by low energy and slow depositional rates, for most of the conodont bearing strata. A much thicker correlative section to the south represents, in large part, a delta front sequence. The Sabine Bay Formation, on the other hand, is composed of shoreface sandstones, possibly in a barrier island setting. The results of this research indicate that conodonts may be very promising for correlation of Permian strata in the Canadian Arctic Archipelago and for worldwide comparison. More work within the Sverdrup Basin, including both marginal and basinal sections , is necessary to provide a good biozonation of these marine Permian strata. The use of the abundant brachiopods in combination with the conodonts is probably the best way to resolve this zonation. The taxonomic.descriptions and subdivisions proposed herein should provide a foundation for future work. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

No description available.

No description available.

The Lysorophia is an order of small, but extremely elongate and tiny-limbed aquatic lepospondyl amphibians existing from the Middle Pennsylvanian through the Lower Permian, primarily in North America. The order comprises one family, Cocytinidae, with three recognized species: Brachydectes newberryi (=Cocytinus gyrinoides), B. elongatus (=Lysorophus tricarinatus, partim) and Pleuroptyx clavatus. Other named species are considered Lysorophia, incertae sedis. Lysorophoids are distinguished by their fenestrated skulls, anteriorly sloping suspensoria, short mandibles (each bearing a lateral mandibular fenestra) and by extensive, well-ossified hyobranchial skeletons. Presacral vertebrae are holospondylous and number between 69 (B. newberryi) and 97 (B. elongatus). Neural arch halves are sutured at their midlines and to their centra. Aspects of lysorophoid anatomy, including the hyobranchial skeleton, suggest that the lysorophoids are neotenic. / While closely similar to one another, lysorophoid species are highly derived relative to other Paleozoic amphibians. They are most closely related to microsaurs, principally through the morphology of the craniovertebral articulation.

No description available.