A New Extinct Emydid Turtle from the Lower Pliocene of Oklahoma

In the summer of 1946 a University of Kansas field team ventured into the marl beds of Oklahoma’s Laverne Formation, where they uncovered the fragmented remains of an ancient turtle. The find turned out to be a previously unknown species of the genus Chrysemys, distinguished by a uniquely concave front of the carapace, a broader, more sculptured shell, and an unusually indented plastron. Detailed measurements and careful comparisons with modern relatives reveal how this creature differed in size, shell texture, and the shape of its margins, offering a rare glimpse into turtle evolution during the early Pliocene.

The paper walks listeners through the painstaking process of piecing together the damaged fossil, describing each preserved bone fragment and the clues it provides about the animal’s anatomy. By situating the specimen within its geological context and contrasting it with living turtles, the study highlights the diversity of ancient freshwater turtles and the value of the Laverne formation as a window into past ecosystems.