A Unique Discovery in Colorado: The Story of a Swamp Dweller

In the heart of Northwestern Colorado, near the small town of Rangely, a paleontology team from the University of Colorado has been digging for over 15 years. Recently, they made a remarkable discovery – the jaw of a Heleocola piceanus, a creature that roamed the swamps of the area 75 million years ago. This ancient animal was unlike others of its time. It was about the size of a muskrat and weighed up to two pounds, making it relatively large for a Cretaceous period mammal. Most mammals from that era were smaller, similar in size to modern rats and mice. Professor Jaelyn Eberle, the curator of fossil vertebrates at the CU Museum of Natural History, explained that the discovery shatters the old notion that all mammals back then were tiny. "They're not all tiny, " she said. "There are a few animals emerging from the Late Cretaceous that are bigger than what we anticipated 20 years ago. " Before a devastating asteroid event 66 million years ago, which nearly wiped out all non-avian animals, many mammals were smaller, and their fossils are often identified by their teeth. 70 million years ago, Colorado was a starkly different place. It was part of an inland sea, surrounded by vast marshes and swamps. The fossil was found in a spot where the land met the sea back then. The area was home to unique creatures, including the swamp dweller, turtles, and massive crocodiles. "The region might have looked kind of like Louisiana, " said Rebecca Hunt-Foster, a co-author of the study. "We see a lot of animals that were living in the water quite happily like sharks, rays, and guitarfish. " The excavation team, led by John and ReBecca Foster, has been dedicated to their work in western Colorado. They've celebrated the unique finds that come from less explored areas. "It’s a small town, but in my experience as a paleontologist, a lot of cool things come out of rural environments, " Eberle noted. "It’s nice to see western Colorado have an exciting discovery. " The discovery has attracted scientists from around the world, highlighting the richness of western Colorado’s fossil record.