An exceptionally well-preserved duck-billed hadrosaur present in North Dakota hints that dinosaur mummies could also be extra frequent than we predict
12 October 2022
A 70-million-year-old dinosaur has preserved pores and skin with gashes that counsel it was partially eaten by crocodile-like carnivores and probably different animals – which can assist clarify why it grew to become mummified.
Because it was ripped aside, the estimated 7-metre-long duck-billed hadrosaur in all probability misplaced most of the bodily fluids and gases that promote decay, after which dried out earlier than turning into buried beneath a number of layers of sediment.
Stephanie Drumheller-Horton on the College of Tennessee at Knoxville, a palaeontologist specialising in crocodile bites, was contacted by Clint Boyd at North Dakota Geological Survey in Bismarck to research the mummified stays of an Edmontosaurus dinosaur, discovered on the Hell Creek Formation of south-west North Dakota.
The fossil was exceptionally well-preserved, with a number of gashes and punctures within the forelimb and tail. The arc-shaped sequence of holes and scrapes on the arm and hand bones and pores and skin had been nearly definitely made by crocodile-like enamel grabbing on to the hadrosaur, she says. A set of longer, V-shaped gashes within the pores and skin – particularly alongside the once-meaty tail – might have been made by the claws of a a lot bigger carnivore, probably a juvenile Tyrannosaurus rex.
“Actually no matter it was, the harm on the tail was bodily bigger than no matter was engaged on the arm,” says Drumheller-Horton. “So we predict we have now not less than two totally different animals concerned, and probably extra.”
The assaults in all probability emptied the cadaver in a method that slows decay – a phenomenon already recognized in forensic evaluation of contemporary specimens. “So as an alternative of all of that stuff sticking round contained in the physique, holding it moist, pushing that decomposition alongside, it’s now out of the best way,” says Drumheller-Horton. “It’s mainly hollowed out and capable of dry out, and what you may have left behind is pores and skin and bones.
“In honour of Halloween, I’ve been jokingly calling it a skeleton in a pores and skin bag,” she says.
Even so, harm marks in smooth tissue, like pores and skin, don’t essentially maintain their unique form, which makes it harder to determine what occurred, she says. The crew is uncertain whether or not the hadrosaur was attacked by predators earlier than demise or by scavengers after demise – or each.
The findings overturn the notion that dinosaur mummies solely happen in distinctive circumstances of very fast burial or sudden drying, says Drumheller-Horton. In addition they counsel that mummification isn’t as uncommon as beforehand thought, as many partially eaten dinosaurs in all probability dried out earlier than turning into buried beneath layers of sediment.
It’s extra possible that when scientists come throughout mummified dinosaur pores and skin – which is extraordinarily skinny and fragile – they both mistake it for a easy imprint, or they by no means see it as a result of it’s unintentionally destroyed because the fossil is faraway from the sediment.
Journal reference: PLoS One, DOI: 10.1371/journal.pone.0275240
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