Lower vertebrates from an Arikareean (earliest Miocene) fauna near the Toledo Bend Dam, Newton County, Texas

Abstract

A recently discovered vertebrate fossil-bearing locality in the Fleming Formation of easternmost Texas has revealed a highly diverse fauna that contains a minimum of 44 early Miocene vertebrate taxa. At least 17 different species of lower vertebrates were recovered including five fish, two amphibians, one lizard, two snakes, at least five chelonians, and two crocodilians. A tiny boid that compares favorably with Anilioides nebraskensis is the first record in the Gulf Coastal Plain, and remains of a large aquatic turtle referred to the genus Dermatemys possibly represent its first fossil occurrence. Other rare genera represented include the largemouth bass Micropterus, possibly the snook Centropomus, and the crocodilian Gavialosuchus. In addition, temporal and spatial range extensions are recorded for Micropterus and Alligator olseni. These taxa, along with the mammalian component to be discussed elsewhere, document the rare preservation of a forested subtropical to tropical coastal lowland paleoenvironment and provide evidence to imply that separation into mid-continent and coastal plain paleobiogeographic provinces had not yet occurred.