Paleontologists from Colorado have found a rare mammal fossil called Heleocola piceanus, which is 70-75 million years old. The discovery shows that some ancient mammals were larger than previously thought. A team of paleontologists near Rangeley, Colorado, has discovered a new (or rather old) resident of the state; A fossilized mammal the size of a muskrat that probably roamed the swamps during the age of dinosaurs.
Researchers led by Jaelyn Eberly of the University of Colorado Boulder published their findings in the journal PLOS ONE.
Eberle and his colleagues named their discovery, which they identified from a jawbone fragment and three molars, as follows: Heleocola piceanus. The animal lived in Colorado about 70-75 million years ago; this at a time when a vast inland sea covered much of the American West. (Accordingly, “Heleocola” roughly translates to “swamp dweller” in Latin).
“Colorado is a great place to find fossils, but mammals from this period are extremely rare,” said Eberle, curator of vertebrate fossils at the CU Museum of Natural History and professor in the Department of Geological Sciences. “So it’s great to see this time preserved in Colorado.”
Compared to much larger dinosaurs that lived at the time, such as tyrannosaurs or the horned ancestors of triceratops, the new fossil remains from Colorado may seem small and insignificant. But it was surprisingly large for a mammal at the time, Eberle said.
He’s also pleased to have gotten his due for Rangeley, located in the northwestern corner of the state near Dinosaur National Monument.
“This is a small town, but in my experience as a paleontologist, a lot of interesting things come out of rural environments,” Eberle said. “It is great to see an exciting discovery being made in Western Colorado.”
Earth meets water
This remarkable discovery helps paint a more complete picture of Colorado that is almost unrecognizable to residents today.
Paleontologists John Foster and Rebecca Hunt-Foster, co-authors of the new study, have been coming to this part of the state every summer to dig for fossils for about 15 years. This is where land met water seventy million years ago. Here creatures like turtles, platypus dinosaurs, and giant crocodiles may have thrived in and around marshes and estuaries, feeding on wetland vegetation, fish, and more.
“This area may have looked like Louisiana,” said Rebecca Hunt-Foster, a paleontologist at Dinosaur National Monument in Utah and western Colorado. “We see many animals living quite happily in the water, such as sharks, stingrays and guitarfish.”
John Foster remembers first seeing a piece of the mammal’s jaw in a sandstone layer he collected from the area in 2016. The fossil was about an inch long.
“I said, ‘Oh my God, this is huge,'” said Foster, a research scientist at the Utah Field House Museum of Natural History State Park in Vernal, Utah.
a big tits
Eberle explained that before an asteroid wiped out non-avian dinosaurs 66 million years ago, mammals tended to be small, most about the size of a modern mouse or rat. He recognizes them mostly by the tiny teeth they leave behind.
H. piceanus for comparison It was very big. Eberle estimates that this animal, a cousin of modern marsupials, weighed 2 pounds or more, more than most Late Cretaceous mammals. (This isn’t exactly a record; another fossil mammal from the same period, known as Didelphodon, may have weighed 11 pounds.) Judging by the teeth, H. piceanus The mammal probably ate plants along with a few insects or other small animals.
While dinosaurs get all the credit, the new discovery is another reason paleontologists shouldn’t ignore ancient mammals. Small or small, they played an important role in Colorado’s Late Cretaceous ecosystems.
“They’re not all small,” Eberle said. “There are a few animals that come out of the late Cretaceous period, and they are larger than we expected 20 years ago.”
The Mountain West is a special place for fossil lovers, Hunt-Foster said. He also called on citizens visiting public areas not to collect vertebrate fossils such as dinosaurs that they may encounter during the walk, in order not to spoil important scientific information. Instead, they need to note the location, take photos, and alert a representative of the nearest museum or state land agency.
“We have scientists from all over the world who come specifically to study our fossils,” he said. “We’re really lucky.”
Source: Port Altele
