Colorado 'swamp dweller' mammal

Working near Rangely, Colorado, paleontologists have uncovered an unknown state resident—a fossil mammal about the size of a muskrat that may have scurried through swamps during the Age of Dinosaurs.

They identified the creature from a piece of jawbone and 3 molar teeth, and named it Heleocola piceanus. It lived in Colorado roughly 70 to 75 million years ago, at a time when an inland sea covered large portions of the American West. “Heleocola” roughly translates to “swamp dweller” in Latin.

Said one team member, “Colorado is a great place to find fossils, but mammals from this time period tend to be pretty rare. So it’s really neat to see this slice of time preserved in Colorado.”

Compared to the much larger dinosaurs living at the time, like tyrannosaurs or horned ancestors of Triceratops, this new fossil might seem tiny and insignificant. But it was surprisingly large for mammals at the time.

This discovery helps paint a more complete picture of a Colorado that would be all but unrecognizable to residents today. Seventy million years ago, this area was where land met water. Creatures like turtles, duck-billed dinosaurs and giant crocodiles may have flourished in marshes and estuaries, gorging themselves on wetland vegetation and fish.

The bit of mammal jaw emerged from a slab of sandstone that was collected from the site in 2016. The fossil measured about an inch long.

Before an asteroid killed off the non-avian dinosaurs 66 million years ago, mammals tended to be small—about the size of today’s mice or rats. They are largely identified from the tiny teeth they left behind.

In comparison, this one was positively huge. A cousin to modern-day marsupials, this animal weighed 2 pounds or more. But it’s not quite a record. The Didelphodon, another fossil mammal from the same period, may have weighed as much as 11 pounds. H. piceanus’ teeth indicate it dined on plants, with a few insects or small animals mixed in.

 

https://www.msn.com/en-us/news/technology/paleontologists-discover-colorado-swamp-dweller-mammal-that-lived-alongside-dinosaurs/ar-AA1sNCLe?ocid=hpmsn&cvid=ed46623d933043f19069e3bf9a8f9350&ei=83