These fossil mummies reveal a brutal world long before T. rex lived

It was a time of catastrophic change. Most life on Earth had been wiped out, global temperatures had risen dramatically, and weather was raging at extremes. That anything survived in this hostile environment is remarkable, and yet some plants and animals survived. One of those survivors was Lystrosaurusa four-legged herbivore with a beak-shaped snout and two pointed tusks. And now, over 250 million years later, paleontologists have uncovered two fossils of these tiny animals complete with mummified skin.

This exciting discovery is described in a paper Published in Paleogeography, paleoclimatology, paleoecology. The two Lystrosaurus Fossils are among the 170 fossils from the Karoo Basin of South Africa examined in this article. The Karoo is one of only a few places in the world that records the boundary between the Permian and Triassic periods, a boundary that includes the End-Permian Extinction Event (EPME) that caused most marine and killed land creatures.

Lead author Roger Smith has worked there for 47 years. He is a distinguished professor at the Institute for Evolutionary Research from the University of the Witwatersrand and emeritus research associate Iziko South African Museum in Cape Town. He and his colleagues Jennifer Botha and Pia Viglietti studied a well-known outcrop Lystrosaurus hotspot, after producing more than 500 fossils. But for this paper, they focused on 170 tetrapod fossils — a term that refers to four-legged vertebrates — all from a specific time period known as the Induan Age, the covers the million years after the EPME. Among the many Fossils examined in this outcrop cluster from four to eight Lystrosaurus Fossils were found close together, their bodies with their arms outstretched, two of them preserved mummified skin.

That skin, Smith explained in a video callwas almost what he had predicted: the animal was hairless, as evidenced by the absence of hair follicles, but it was not scaly, either. Noting that the scales often don’t last, he likened them to elephant skin: leathery but dimpled. “The idea that it was like a transitional fossil — between scaly and actually hairy — is almost confirmed by the texture of that skin,” he said.

Juan Carlos Cisneros is a paleontologist at the Federal University of Piauí in Brazil. While not involved in this research, he has also worked in the Karoo Basin and previously worked with Smith. “This is the closest thing to a photograph from the time,” he said, comparing the mummified fossils to “a time capsule.”

“We are usually satisfied with nice teeth and bones, and every once in a while we find a complete skeleton. But nobody else finds mummified skin. Certainly not at this age! We’re talking about things older than dinosaurs,” he enthused. “Nobody found such a beautiful preservation at that time, so detailed.”

What offers an exquisite glimpse into animals over 250 million years old is also an indication that they met a horrible end. Examination of the bone microstructure of two of the fossils suggests they were young. The authors believe that the position and age at which this Animals died are indications that they collapsed near a dried up water source. They point to examples of today’s young elephants in similar drought conditions, starving in a “sudden death posture” with eagles spread, and most importantly, their skin quickly dries out and also mummifies.

These assemblages of fossils, along with the others examined in this outcrop, suggest they were herds of young Lystrosaurus died as a direct result of the drought. Substantial evidence of drought can be found in the sediment layers in the Karoo Basin, in geochemical isotope analyses, and in these and others Fossils described in a number of publications. It is therefore surprising that Smith claims, “Even though the world was devastated, the resulting ecosystem was still fully functional.”

In other words, the planet may have been completely transformed – and into a hostile one at that – but life, to paraphrase the words of a major motion picture, still found a way.

There is evidence that terrestrial animals in the Karoo at this time grew rapidly, matured earlier, lived short lives, and were generally smaller. A kind of Lystrosaurus during the Permian were for example larger than those found in the Triassicbut it is also important to note that all Lystrosaurus Fossils discovered so far from the Triassic come from young people and adolescents.

Cisneros compared the greatness of Lystrosaurus after the EPME to a small pig and said it was “the largest land animal of the time”. Everything that survived the mass extinction was small.”

“Before the extinction,” Smith agreed, “it was fashionable to be big and heavy and to be a ruminant. But after that it was no longer successful.”

Digging underground is one of the behaviors believed to have helped Lystrosaurus survive the extinction and extreme heat that followed this event. But that’s not all, and some of the other survival strategies involve, if not interspecies cooperation, then at least interspecies tolerance. In one example, the authors refer to the fossils of two different ones Lystrosaurus Species that died together, suggesting that these species may have foraged together rather than competing for it.

Sharing shelter with other contemporary species was another example. In three cases including several species Lystrosaurus were found together in association with long tubular cave casts, strongly suggesting that these animals found shelter – and died – together.

In these ancient common shelters, three of the species were four-legged reptiles (Thrinaxodon, Galesaurus and Lystrosaurus); one of them (prolacerta) was a four-legged archosauromorph—a lineage that eventually gave rise to crocodiles and dinosaurs.

Smith said he and his colleagues are finding further evidence “that these dinosaur ancestors were not only able to live there, but were also able to diversify and become the dominant animals in the Triassic. “This,” he concluded, “is the beginning of the rise of the dinosaurs.”

While the causes of EPME continue to be debated, the authors draw on their work in the Karoo Basin to support the hyperthermal cause of the extinction, implying that Earth was catastrophically struck by a volcanic eruption in the Siberian Traps 252 million years ago an event that changed the weather through volcanic emission of greenhouse gases and acidic particles. This had devastating consequences, including “vegetation dieback and drought (drought with shorter and unpredictable rainy seasons) on land,” Smith explained, and “deacidification and acidification of the oceans.”

“We are now treating this as pangea-wide hyperthermia,” Smith added, referring to the only continent that comprised land on Earth at the time. “Therefore, Pangea-wide drought episodes would be expected.”

This release, he noted, is part of a larger project he and his colleagues have been working on in the Karoo Basin: just one of the many releases that have preceded it, and other exciting releases to come.

“There is still much to be clarified,” Smith admitted, adding that he believes that when he and his colleagues complete their research on the Permo-Triassic Boundary Interval (PTB) of the Karoo, “the type locality will be recognized for.” the extinction of the earth at the end of the Permian.”

“The Karoo has the best and most complete fossil record of these Permian-Triassic tetrapods,” agreed Cisneros. “If you would expect it anywhere in the world, it would be in the Karoo.”

Jeanne Timmons (@mainly mammoths) is a New Hampshire-based freelance writer who blogs about paleontology and archeology at mostmammoths.wordpress.com.