‘Swimming’ dinosaur fossils recovered
Giant land creatures are well known to have wandered the terrain we know now as western Colorado, but the shallow seas were similarly filled with predators as hungry as their land-lubber counterparts.
The remains of one of them, an elasmosaurid, was found at the base of the Bookcliffs earlier this year.
“It’s definitely the largest” of the three or four finds of similar creatures in the Grand Valley, said John Foster, curator of paleontology for Dinosaur Journey.
The discovery of the elasmosaurid expands the knowledge of the creatures that populated the seas of the late Cretaceous period.
It appears to be a bit younger than the remains of a xicanthinus that lay for millions of years in the muds that became the Mancos Shale below the Bookcliffs until it was unearthed bit by bit by a family and then by Museum of Western Colorado researchers.
Elasmosaurids were marine reptiles with short tails, long necks and paddles that propelled them along.
The vertebrae found near the Bookcliffs suggest a creature stretching to about 40 feet from teeth to tail, Foster said. The bones now in the possession of the museum appear to be from the back end of the creature, he said.
The museum holds the fossils under a permit from the Bureau of Land Management.
The vertebrae were weathered and much of the bone matrix had been eroded away, but Foster said he hopes to return to the site later this year to determine if more of the creature can be found.
Not only would that shed light on the sea creatures of the Cretaceous period, but also on the shadowy background of elasmosaurids themselves.
“Elasmosaurids are pretty rare,” Foster said.