
Mesonychid teeth and jaw/NPS.
When someone asks you to imagine a mammal with hooves, what pops into your mind? An antelope? A horse? Perhaps a bison? For most of us, we imagine a vegetarian creature, grazing on the grasslands of America. In a startling new discovery, the first known mesonychid (meat-eating hooved mammal) from the Pacific Northwest has been found within the Clarno Unit of John Day Fossil Beds National Monument.
As reported in the online, open access journal Palaeontologia Electronica, Ms. Selina Robson of the University of Calgary, Dr. Nicholas Famoso of John Day Fossil Beds National Monument, as well as Dr. Edward Davis and Dr. Samantha Hopkins of the University of Oregon used CT scans to re-identify a fossil jaw from the Clarno Unit. Their discovery: the jaw belongs to the massive bone-cracking mesonychid, Harpagolestes cf. uintensis. If one zoomed back in time to the Paleogene Era (66 - 23 million years ago), this unique animal roamed the northern half of the globe.
The jaw sat misidentified in the fossil collection of the University of Oregon Museum of Natural and Cultural History in Eugene, Oreon for about 50 years before it was looked at in detail. There are now three known meat-eating mammals from the Hancock Mammal Quarry in Wheeler County, but this mesonycid is the first of the group known from the Pacific Northwest.
Not all fossils can be identified correctly at first glance. Often work needs to be done to remove rock and reveal the shape of the teeth and bones hiding underneath. In some cases, fossils are so delicate that traditional methods of rock removal are not safe for the fossil, so technological methods are used. New innovations, such as CT scanning, help paleontologists identify fossils that were previously impossible to describe, such as those discovered at the John Day Fossil Beds.
“It’s important to reexamine fossils in museum collections because you never know what new discoveries might be hiding in the cabinets,” said Superintendent Patrick Gamman.
The new study, “First mesonychid from the Clarno Formation (Eocene) of Oregon, USA,” can be found online in Palaeontologia Electronica.