STL Science Center

STL Science Center

17 February 2018

The Oldest Sea Turtle

©Jorge Blanco
Desmatochelys is the oldest sea turtle known to science. Consisting of two species, D. lowi Williston 1894 and D. padillai Cadena and Parham, 2015, Desmatochelys is known mostly from Colombian fossils of D. padillai recovered in 2007. However, D. lowi is known from a very well preserved specimen from Nebraska described by Williston in 1894 and potential remains recovered from Kansas in 2008. The reason that the 2007 discoveries and their 2015 description are more well-known is because they are more current, very well preserved, and the description includes an extensive list of characters and depth. All of the known specimens of this turtle genus are amazing, so it really is difficult to say any one is better than the other specimens and each has its merits. As an example, the 2008 Kansas specimen of D. lowii has a very well preserved skull and the humerus is slightly different from Williston's Nebraska specimen of 1894. Variance, preservation, and preparation could account for this, however we may never know exactly why they appear different.

Regardless of their preservational states, the specimens of D. padillai from Colombia was recovered from rocks that are Lower Cretaceous or upper Barremian-lower Aptian, approximately 120 million years old, in age. These fossils make Desmatochelys the oldest known fossil sea turtle by approximately 25 million years. All of the fossils, from all three locations, make Desmatochelys one of the most well represented fossil sea turtles as well. As the week goes on we will list out the specimens and describe this turtle. Today, enjoy this Cretaceous landscape and its giant sea turtle.

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