A newly discovered coinage of mammal has provided a snapshot of sublunar North America that go back 70–75 million geezerhood ago , a time slice that ’s typically not well known . Thankfully , Colorado preserve it well , and this is where a squad of scientist think fogey grounds of a Late Cretaceous “ swamp indweller ” .
The fossil clay included a lower jaw and three molar tooth , belong to an beast that lived in what ’s now Rangely , Colorado , at a time when a vast inland sea covered much of the American West . Its wet milieu are honored in the naming of the new species , Heleocola piceanus , withHeleocolaroughly translating from Latin to “ swamp indweller ” .
WhenHeleocolawas snuffling around , the neighborhood would ’ve more closely resembled Louisiana , explained study co - author ReBecca Hunt - Foster , a paleontologist atDinosaur National Monumentin Utah and westerly Colorado , in astatement . “ We see a mass of animal that were exist in the water system quite happily like shark , rays andguitarfish . ”
Oh to be a Late Cretaceous era muskrat-sized mammal splashing around a swampy version of Colorado that looks like Louisiana (pictured).Image credit: lazyllama / Shutterstock.com
The critter was retrieved from an area of the state that ’s hosted fogy digs every summertime for the last 15 age , but it was in 2016 that the remarkably large mammal made itself known . Its jawbone emerged from a slab of sandstone , as seen by subject area cobalt - author John Foster , a scientist at theUtah Field House of Natural story State Park Museumin Vernal , Utah , who at the time – to put its size of it in context – say , “ Holy cow , that ’s huge . ”
We might not have a slew ofHeleocolato work with – but ground on the dental morphology we have , the squad was able-bodied to patch together some clues as to how the swamp habitant lived , and what exist analogs we can compare it to .
“ Diet - wise , and based on its teeth , Heleocola was plausibly a plant - dominated omnivore , meaning it ate mostly plants , but probably consumed some insects and/or small vertebrates too,”Professor Jaelyn Eberle , conservator of dodo vertebrates at the University of Colorado Museum of Natural History , who led the study , secernate IFLScience . “ It ’s a large mammalian by Late Cretaceous standards ( with an estimated body mass similar to today ’s muskrat ) , whereas most mammals living at this time ( 70 – 75 million years ago ) were computer mouse to rat - sized . ”
Jaw fragment of Heleocola piceanus.Image credit: J Eberle et al 2024, PLoS ONE,CC BY 4.0
“ I think its bombastic size of it is one of the engrossing takeaway , as traditionally Late Cretaceous mammal have been interpreted as tiny and rather peanut ( living in the understory beneath the dinosaur ) . ”
Mammals did n’t really go crack - sized until after the asteroid came along and pour down off the non - avian dinosaur 66 million years ago , prior to which they were all a bit black eye - like . With the arriver of the swampland dweller , we now know that there were some comparative beasts in Colorado 70–75 million years ago that were much liberal than scientist would ’ve previously believe .
The study is published in the journalPLoS ONE .
