Paleontologists have found 50- to 25-million-year-old fossilized footprints of invertebrates and vertebrates, together with a false saber-toothed cat (nimravid), at John Day Fossil Beds Nationwide Monument in Oregon, the USA.
The pawprints of a nimravid from the John Day Formation of Oregon, the USA. Picture credit score: NPS.
John Day Fossil Beds Nationwide Monument (JODA) in central and japanese Oregon is thought for physique fossils of historical mammals.
In accordance with the paleontologists, these specimens comprise a virtually steady, 50 million-year file of mammalian evolution.
4 geological formations are acknowledged inside JODA: Clarno (50-39 million years outdated), John Day (31-25 million years outdated), Mascall (16-12 million years outdated), and Rattlesnake (8-6 million years outdated).
The newly-discovered footprints are a part of the Clarno and John Day formations.
“They reveal fascinating behaviors and species beforehand undocumented within the monument’s in depth fossil file,” the researchers stated.
A set of pawprints present in a 29-million-year-old volcanic ash layer of the John Day Formation was probably made by to a nimravid, a saber-toothed, bobcat-sized predator reminiscent of Hoplophoneus.
The shortage of claw marks helps proof of retractable claws, just like trendy felines.
Three-toed, rounded hoofprints of the identical age are believed to have been made by a big herbivore reminiscent of an historical tapir or rhinoceros.
Two small chook tracks, beak marks and invertebrate trails have been found within the Clarno Formation.
They recommend historical shorebirds foraged for meals in shallow water — habits strikingly just like that seen in trendy species.
“This prehistoric habits from 50 million years in the past remains to be prevalent as we speak in trendy shorebirds,” stated Conner Bennett, a paleontologist at Utah Tech College.
“It’s fascinating. That’s an extremely very long time for a species to exhibit the identical foraging patterns as its ancestors.”
In the identical formation, the scientists discovered a uncommon fossil observe that includes clawed, splayed toes.
It signifies a lizard as soon as dashed alongside a lakebed, marking one of many few identified reptile trackways from this time interval in North America.
“These tracks provide a uncommon window into historical ecosystems,” stated Dr. Nicholas Famoso, a paleontology program supervisor at JODA.
“They add behavioral context to the physique fossils we’ve collected over time and assist us higher perceive the local weather and environmental situations of prehistoric Oregon.”
“The fossil tracks not solely assist us verify the existence of those animals on this time and place, however additionally they inform us how they lived,” Bennett added.
The crew’s findings seem within the journal Palaeontologia Electronica.
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Conner J. Bennett et al. 2025. Following their footsteps: Report of vertebrate fossil tracks from John Day Fossil Beds Nationwide Monument, Oregon, USA. Palaeontologia Electronica 28 (1): a11; doi: 10.26879/1502
