RMDRC), aside from being a mouthful to say, houses a Toxochelys discovered by Mike Triebold in 1993 in Lane County, Kansas. Lane County is in the western and central area of Kansas, near to Colorado, and the stratigraphic layer from which Triebold's Toxochelys was extracted is Niobrara Chalk approximately 83 million years old, according to the RMDRC. Considering the age of the post, nearly 2 1/2 years ago now, I do not know if the RMDRC still holds Triebold's skeleton or a cast, but it is, of course, a possibility and anyone planning a dinosaur trip in Colorado, regardless of the status of housing for this particular Toxochelys ought to still go to the RMDRC. It is worth noting that this skeleton represents a juvenile turtle (the shell is 9.5in (24cm) long) also, a true rarity for two reasons: 1) Juvenile fossils, despite high mortality of young animals of all extant and most likely extinct species as well, are still considered quite rare in the entire fossil record and 2) Juvenile turtle fossils in particular are rare within the realm of juvenile fossils of any kind due to the fact that they were most likely, at this size, swallowed and digested pretty much entirely. Depicting a growth series in the genus, if not in any one species, is also of great help in understanding the ecological role of these turtles.
In that respect, I have seen some sources claiming that these turtles munched on sharks and other large fish. I think that that is a unique and incorrect view, as I do not see a turtle like this either surprising or chasing down a shark let alone chomping into one and holding on long enough to kill it then ingest it. I suppose strange enough things have happened in nature, but I am not inclined to agree that this happened as a regular occurrence, regardless. More likely this turtle ate squid and/or marine vegetation.