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