skin
(Photo : Pixabay / Engin_Akyurt )

A tiny rock that is smaller than a fingernail that was discovered deep inside an Oklahoma limestone cave could broaden current understanding regarding prehistoric skin.

Texture on Rock Turns Out To Be Earliest Skin Fossil Sample From Diverse Animal Classifications

Paleontologists have discovered that the preserved texture serves as the earliest known skin fossil sample from a diverse animal classification called amniotes. They documented the findings in the "Paleozoic cave system preserves oldest-known evidence of amniote skin."

The texture dates back 290 million years, making it 21 million years older compared to the record-holder that went before it. The wearers of the skin appeared to be a reptile. The fossil's pebbly surface appears to be similar to crocodile skin today.

Considering the importance of skin and how it serves as a protective barrier for the body, this finding is considered important when it comes to piecing together evolutionary history. Paleontologist Ethan Mooney from the University of Toronto explains that they get great opportunities to look back in time every now and then. Mooney adds that these kinds of discoveries can enrich current understanding and perception regarding pioneering animals.

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Old Skin Fossil

The fossil record could have been varied and rich. However, there are some body parts that have ended up preserved more rarely compared to others. This is any kind of soft tissue.

However, there are some environments that are proper for soft tissue preservation. The Richard Spur cave system in Oklahoma is one of these environments. Its sediments are oddly fine and soft. Moreover, the insufficiency of oxygen delays the soft tissue's decomposition.

On top of this, in the Permian, the cave was an oil seep that was active. The hydrocarbons in tar and petroleum permeating the sediments would have helped with tissue preservation.

The area is known to have a diverse and rich early tetrapod assembly. Some of the oldest known amniotes have been discovered in the caves of Richards Spurs. Amniotes are a terrestrial vertebrate group that includes birds, mammals, and reptiles.

However, the newly found fossil is remarkably special. It has undergone 3D carboning, making it the first record from the Paleozoic. It also serves as the earliest known preserved skin fossil and includes structures linked to the dermis layer that are deeper.

Unfortunately, since no linked skeleton was found, the animal behind the skin remains a mystery. However, the pebbled surface that does not overlap resembles modern crocodile skin. Moreover, the hinged regions in between the scales is similar to animal skin like that of worm lizards and snakes.

According to the researchers, the discovery reveals that even during the initial divergence of amniotes, skin was already present and significant. They particularly note that the presence of an epidermis with scale-like protuberances and hinges underscores the significance of the component of the skin as it serves as a barrier to protect the creature against a harsh environment.

On top of this, the skin also provides a new tool for the interpretations of further development and emergency of avian feathers and mammalian hair follicles.

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Check out more news and information on Paleontology in Science Times.