Doctor of Philosophy (PhD)
Geology and Geophysics
The late Barstovian Fort Polk herpetofauna represents the most diverse herpetofauna on the Gulf Coast, USA, and includes 15 genera from ten families. The herpetofaunal composition of Fort Polk and Miocene east Texas localities is similar enough to Great Plains localities that they are all considered to be one biogeographical province during the Barstovian. The use of ternary diagrams, ratios of herpetological elements to kg matrix screened, and natricine-colubrine indices, has allowed determining the wetness of the Fort Polk sites. Development of a composite stratigraphic section for North American fossil snakes has allowed recognition of two extinctions of fossil snakes during the Miocene. North American and European Miocene snake faunas display a replacement of boids by colubrids in the Early to Middle Miocene and Late Oligocene, respectively. European fossil snake data show a decrease in colubrid numbers from the Early to Middle Miocene.
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Williams, Michael John, "Miocene herpetofaunas from the central Gulf Coast USA: their paleoecology, biogeography, and biostratigraphy" (2009). LSU Doctoral Dissertations. 1288.
Schiebout, Judith A.