‘Stunningly preserved’ dinosaur ‘mummies’ found in Wyoming have pores and skin and hooves

Skeletons of duck-billed dinosaurs discovered greater than 100 years in the past are so well-preserved that they comprise fleshy physique components of the extinct species embedded in skinny layers of clay, scientists say.

Specimens of Edmontosaurus annectens, identified for his or her lengthy cranium that resembles a duck’s invoice, had been present in japanese Wyoming within the early 1900s. Latest reexamination of these fossils by paleontologists on the College of Chicago revealed that the fossils don’t comprise simply bones, however mummified physique components protected beneath a clay masks, in keeping with a paper revealed final week in Science.

Among the many bones are “stunningly preserved” items of pores and skin, spikes and hooves, the researchers mentioned.

The “fleshy” components should not fossilized flesh however somewhat delicate clay molds fashioned by microbes because the animals decayed, in keeping with the paper.

The uniform clay layers are certain by sandstone, somewhat than true fossilized smooth tissue, doubtless fashioned as a floor template over the decaying carcass, aided by biofilms.

That is in distinction to typical smooth tissue preservation, which happens in fine-grained, oxygen-poor environments, corresponding to lagoons or seabeds, and ends in the fossilization of delicate components corresponding to feathers and pores and skin, the researchers mentioned.

When the specimens had been first found in coarse, oxygenated river deposits, scientists assumed they had been fossilized pores and skin texture and physique components. However additional examination of the unique skeletons — in addition to the findings of two extra mummified E. annectens, a juvenile and an grownup — proved in any other case.

The late juvenile E. annectens is the primary subadult dinosaur mummy and the primary large-bodied dinosaur with a “totally preserved fleshly define,” together with a neck and trunk crest.

The grownup specimen is the primary hadrosaurid to retain its full tail spike row. It’s also the earliest identified tetrapod with hooves, marking the primary reptile with hooved ft, in keeping with the paper.

The midline crest and tail spikes of E. annectens reveal a “way more advanced disguise” than historic restorations have instructed, the researchers mentioned.

The species additionally has useful and morphological similarities to some fashionable squamates, the biggest order of reptiles that accommodates lizards and snakes.