The Lower Devonian carbonate-clastic sequence of southwest Ellesmere Island accumulated in the Franklinian Basin at approximately 15(DEGREES)N latitude. A variety of depositional settings are represented, ranging from tidal flat to basinal environments. These environments can be recognized in Lower Devonian rocks across the Arctic Islands. / Progradation of the carbonate sequence of southwest Ellesmere Island occurred in the Early Devonian, but was periodically interrupted in the Zlichovian/Dalejan by transgressive events. Upward movement in the newly named Inglefield Uplift occurred throughout the Devonian, and shed clastic sediments westward that, in Middle to Late Devonian time, finally overwhelmed the marine carbonates and resulted in fluvial deposition on southern Ellesmere Island. / Certain formations in the Lower Devonian sequence are profusely fossiliferous, in particular the Blue Fiord Formation, which contains an abundant fauna including numerous species of coral and brachiopods. Both of these groups belong to the Old World Biogeographic Realm, and indicate a Zlichovian age for the lower Blue Fiord Formation of southern Ellesmere Island.

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.

Thesis (Ph.D.)--University of Western Australia, 2003.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

No description available.

Condodont biostratigraphy has been established for complete sections of the Mifflintown, Wills Creek, and Tonoloway formations along the Wills Mountain anticline in the Central Appalachians. Beds in the Central Appalachians formerly called the Rochester Formation have been renamed the Cosner Gap Member of the Mifflintown Formation. The type section of the unit is at Cosner Gap, northwest of Maysville, Granty Count, West Virginia. Use of the name, Rochester Fornation is restricted to the New York section. The succession of conodont faunas described for these formations range from latest Wenlock through Pridoli in age. The fauna includes 46 form species assignable to the form genera Hindeodella, Ligonodina, Lonchodina, Neoprioniodus, Ozarkodina, Panderodus, Plectospathodus, Spathoenathodus, and Trichonodella. Sixteen new form species are described and twelve of these are named: Ligonodina brevis, Ozarkodina edithae mariae, Q. typica intermedia, O. serrata, Q. sinuosa, O. ziegleri crassatoides, Spathognathodus bicornutus, S. primus highlandensis, S. primus multidentatus, S. tillmani, S. walliseri, and Synprioniodina lowryi. One platform species, possibly representing a new form genus, occurs in the upper Tonoloway Formation. The important European forms Spathognathodus sagitta bohemicus., S. snajdri, S. crispus, and S. steinhornensis eosteinhornensis, are reported for the first time from the Central Appalachians. Eleven multi-element conodont species are recognized using open nomenclature. The faunas of the S. sagitta bohemicus, S. snajdri, S. crispus, and S. steinhornensis eosteinhornensis zones correlate with the sagitta, snajdri horizon of the siluricus, crispus, and eosteinhornensis zones of Walliser. The S. bicornutus and S. tillmani zones are tentatively correlated with Walliser's crassa and latialatus zones. The ploeckensis Zone of Walliser was not identified, but its stratigraphic position would be similar to that of the unzoned interval of the middle third of the McKenzie Member of the Mifflintown Formation. / Ph. D.

Thesis (Ph.D.(Geology))--University of Pretoria, 2008. / Includes summary and abstracts in English. Includes bibliographical references and index.

Call number: LD2668 .T4 1964 P31 / Master of Science

Jawed vertebrates (gnathostomes) consist of two clades with living representatives, the chondricthyans (cartilaginous fish including sharks, rays, and chimaeras) and the osteichthyans (bony fish and tetrapods), and two fossil groups, the "placoderms" and "acanthodians". These extinct forms were thought to be monophyletic, but are now considered to be paraphyletic partly due to the discovery of early chondrichthyans and osteichthyans with characters that had been previously used to define them. Among these are fin spines, large dermal structures that, when present, sit anterior to both median and/or paired fins in many extant and fossil jawed vertebrates. Making comparisons among early gnathostomes is difficult since the early chondrichthyans and "acanthodians", which have less mineralized skeleton, do not have large dermal bones on their skulls. As a result, fossil fin spines are potential sources for phylogenetic characters that could help in the study of the gnathostome evolutionary history. This thesis examines the development and internal structure of fin spines in jawed vertebrates using two-dimensional (2D) thin sections and three-dimensional (3D) synchrotron datasets. The development of the dorsal fin spine of the holocephalan, Callorhinchus milii, was described from embryos and compared to that of the neoselachian, Squalus acanthias, whose spine has been the model for studying fossil shark spines. It was found that the development of the C. milii fin presents differences from S. acanthias that suggest it might be a better candidate for studying "acanthodian" fin spines. The 3D histology of fossil fin spines was studied in Romundina stellina, a "placoderm"; Lophosteus superbus, a probable stem-osteichthyan; and sever­­al "acanthodians". The 3D vascularization reconstructed from synchrotron radiation microtomographic data reveal that "acanthodian" and Lophosteus spines grew similarly to what is observed in chondrichthyans, which differs slightly from the growth of the Romundina spine. Chondrichthyans and "acanthodians" also share similarities in their internal organization. Overall, Lophosteus and Romundina spines are more similar in terms of morphology and histology compared to chondrichthyans and "acanthodians". These results support the current hypothesis of gnathostome phylogeny, which places "acanthodians" on the chondrichthyan stem. They also emphasize the need for further study of vertebrate fin spines using 3D approaches.

<p>There continues to be a lack of agreement concerning the precise phylogenetic placement of Proconsul despite the wealth of fossil material and the extensiveness of its study. The difficulty in resolving the phylogenetic status of this important and well represented Miocene catarrhine is a consequence of its apparent basal position relative to crown catarrhines. This position complicates the inference of character polarities. This dissertation tests three previously proposed hypotheses concerning the phylogenetic position of Proconsul: (1) Proconsul is a stem catarrhine; (2) Proconsul is a stem hominoid; and (3) Proconsul is a basal hominid, most closely related to extant great apes and humans. A phylogenetic analysis based on 719 characters drawn from the skull, forelimb, pelvis and foot, and sampling a diversity of extant anthropoid taxa, offers no compelling support for a hominoid clade that includes Proconsul. The radiation of crown catarrhines involved rapid evolutionary changes from the ancestral catarrhine morphotype, resulting in stem catarrhines appearing much more similar to each other, even where there are key synapomorphies linking them with crown clades. As a result, systematic analyses alone are insufficient to confidently support a single optimal phylogenetic hypothesis. Further exploration of the data, by combining inferred ancestral morphotypes with phenetic visualizations of character evolution, demonstrated that inclusion of Proconsul among Hominoidea or Hominidae pushed the ancestral catarrhine morphotype closer to these clades, respectively. Given a more comprehensive analysis of character evolution under each hypothesis, this dissertation supports the hypothesis that Proconsul is a stem catarrhine. In addition to helping clarify the long-running debate about the phylogenetic status of Proconsul, the results offer fresh insights into the early stages of hominoid evolution and demonstrate the importance of comprehensive phylogenetic analyses in helping to resolve the relationships of problematic stem taxa.