Prehistoric Period
When researching the Big Bend slider's (Chrysemys gaigeae) ancient life, it is necessary to look into the turtle family tree and, more especially, the Big Bend slider's unique ancestry. Although there is little direct evidence of Chrysemys gaigeae in ancient times, we may learn more about its existence by looking at its family tree.
Fossils of turtles, as a group, have been found in sediments from the late Triassic era, more than 200 million years ago. This extensive history includes the Big Bend slider and its family, the Emydidae. Many different kinds of pond turtles, or Emydidae, have developed over the course of millions of years. This family's evolutionary tree reveals that its progenitors adapted to different habitats across different periods of prehistory.
The painted turtle, Big Bend slider, and other members of the genus Chrysemys probably descended from these long-gone emydid turtles. Even though it is difficult to precisely date and identify species within the genus Chrysemys, fossil evidence suggests that this group of fishes has been around for at least a few million years. This lends credence to the idea that Chrysemys gaigeae and other ancient turtles may have evolved from a common ancestor.
Freshwater turtles were able to thrive in prehistoric ecosystems, including those in what is now the southwestern United States. There is a lengthy history of river systems and aquatic environments in the Rio Grande basin, where the Big Bend slider is presently located, that might have supported ancestral versions of the species.
North American fossils of various turtles from the Cenozoic period (the most recent 66 million years) provide credence to the theory that freshwater turtles have long called this area home.
The omnivorous diet and fondness for slow-moving waters are two examples of the ways in which the Big Bend slider has adapted to suit its environment. These characteristics have evolutionary roots in our shared ancestors' ability to adapt to and prosper in harsh conditions. As a result, the Big Bend slider as we know it now probably didn't exist in its identical form in ancient North American rivers, but its evolutionary ancestors probably did.
Direct fossil remains pertaining to Chrysemys gaigeae are few and far between. The circumstances necessary to preserve turtle remains are not always available, and fossilization is an incredibly unusual occurrence, therefore this is typical for many species. Fossil evidence from other turtle groups, however, lends credence to the idea that contemporary emydids—including the Big Bend slider—had a lengthy history in North America.
