These fossil mummies reveal a monstrous world long before the life of a T-Rex

Lystrosaurus murrayi juvenile skeleton with encapsulated coat interpreted as mummified skin.

childish Listrosaurus moray Layer-coated skeleton interpreted as mummified skin.
picture: Courtesy Roger Smith

It was a time of catastrophic change. Most life on Earth has been wiped out, global temperatures have increased dramatically, and the weather has intensified in extremes. That anything survived in this hostile environment is remarkable, however, some plants and animals persisted. He was one of those survivors Listerosaurusa four-legged herb with a beaked nose and pointed, tusk-like teeth. And now, more than 250 million years later, paleontologists have discovered two craters of these tiny animals Complete with mummified leather.

This exciting discovery is described in paper Posted in Paleogeography, paleoclimatology, paleoecology. Tis two Listerosaurus The fossils are among the 170 fossils from the Karoo Basin in South Africa studied in this paper. Karoo is one of the few places in the world that records the boundary between the Permian and the Triassic, a boundary that includes the End Permian Extinction Event (EPME) that killed most marine and terrestrial life about 252 million years ago.

Lead author Roger Smith has been working there for 47 years. He is an outstanding professor in institute for evolutionary studies of the University of the Witwatersrand and Honorary Research Fellow at South African Museum Iziko in Cape Town. He and colleagues Jennifer Botha and Pia Viglietti studied a known bump Listerosaurus hot spotMore than 500 fossils have been produced. But in this paper, they focus on 170 fossil tetrapods — a term for four-legged vertebrates — all from the time Known as the Indian Era, which covers million years after EPME. Among the many Fossils have been studied in this outcrop, groups of four to eight Listerosaurus Fossils were found close to each other, their bodies spread out in the form of an eagle, two of which preserve mummified skin.

This skin, Smith explained in a video callalmost matches what he expected: the animal had no hair, as evidenced by the lack of hair follicles, but it was not scaly, also. Note that the scales do not often keep, and he likened it to elephant skin: it is leathery but has dimples. “The idea that it was like a transitional crater – between a scaly and a real hair – is almost embodied in the texture of that skin,” he said.

Close-up of interpreted pustular surface tissue of mummified skin.

Close-up of interpreted pustular surface tissue of mummified skin.
picture: Courtesy Roger Smith

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

“We’re usually happy with nice teeth, nice bones, and once in a while we find a complete skeleton. But nobody else finds mummified skin. Not at that age, for sure! We’re talking about things that are older than dinosaurs,” he enthused. “Nobody finds that kind of beautiful preservation, so detailed, at that time.”

What provides exquisite insight 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 these animals died are clues that they collapsed near a dried-up water source. They point to examples of today’s young elephants in similar drought circumstances, which die from starvation in a spread-eagled “sudden death posture” and whose skin, notably, dries out quickly and also mummifies.

Georgina Farrell excavating the mummified Lystrosaurus fossil

Georgina Farrell excavating the mummified Lystrosaurus fossil
Photo: Courtesy Roger Smith

These clusters of fossils, along with the others studied in this outcrop, indicate that herds of young Lystrosaurus died as a direct result of drought. Substantial evidence for drought is found in the sedimentary layers in the Karoo Basin, in geochemical isotopic analysis, and within these and other fossils described in a number of papers. Which is why it is surprising that Smith maintains that “Even though the world had been devastated, the resulting ecosystem was still fully functioning.”

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

Evidence suggests that terrestrial animals in the Karoo at this time grew fast, matured earlier, lived short lives, and were generally smaller. Species of Lystrosaurus during the Permian, for example, were is larger than that of the Triassicbut it is also important to note that all files Listerosaurus The fossils discovered so far from the Triassic period are for juveniles and descendants.

Compare Cisneros Size Listerosaurus After EPME to piglet he said that “it was the largest land animal at the time. Everything that survived the mass extinction was a small one.”

Smith agreed, saying, “Before the extinction, the ruminants were big and heavy and the ruminants were. But after that, it was no longer successful.”

Underground digging is one of behaviors He thinks it helped Listerosaurus It survives the extinction and extreme heat that followed that event. But that’s not all, and some other survival strategies include, if not inter-species cooperation, then at least inter-species tolerance. In one example, the authors refer to two different fossils Listerosaurus Species that died out together, suggesting that these species may have been feeding together, rather than competing for it.

Sharing the shelter with other contemporary species was another example. In three cases, many species including Listerosaurus They were found together in conjunction with long, tubular burrow casts, strongly suggesting that these animals protected—and died—together.

Within 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 would eventually give rise to crocodiles and dinosaurs.

Smith said he and his colleagues found more evidence “now that the ancestors of dinosaurs not only were able to live there, but were able to diversify and become the dominant animals of the Triassic period. This is the beginning of the rise of the dinosaur,” he concluded.

While the causes of EPME are still debated, the authors rely on their work in the Karoo Basin to support the cause of the hyperthermic extinction, meaning that Earth was catastrophically affected by a volcanic eruption in Siberian traps around 252 million years ago, the weather was altered by volcanic emission of greenhouse gases and acid particles. This had serious consequences, including “vegetation death and dehydration (drought with shorter and unpredictable periods of rain) on Earth,” Smith explained, as well as “deoxygenation and ocean acidification.”

“We are now treating this as a Pangea-wide high heat,” Smith added, referring to the only continent that consisted of land on Earth at the time. “Therefore, droughts are expected at the level of Pangea.”

He noted that this paper is part of a larger project that he and his colleagues have been working on within the Karoo Basin: just one of the many papers that preceded it and other exciting papers yet to come.

“There is still a lot to be resolved,” Smith admitted, adding that he believes that when he and his colleagues complete their research on the Karoo Permo-Triassic Boundary (PTB), he believes they will be “recognized as the type locality of the end-Permian extinction event.” terrestrial.”

Cisneros agreed: “The Karoo has the best complete fossil record of these tetrapods from the Permian Triassic.” “If there’s anywhere in the world you expect to find it, it’s in Karoo.”

Jane Timmons (Tweet embed) is a freelance writer based in New Hampshire, who blogs about paleontology and archeology in mostmammoths.wordpress.com.