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

Juvenile Lystrosaurus murrei skeleton with layer interpreted as mummified skin.

teen Lystrosaurus Murrei Skeleton with layer interpreted as mummified skin.
photo, Courtesy Roger Smith

It was a time of devastating change. Most of the life on Earth was wiped out, global temperatures had risen dramatically, and the weather was at its peak. What is left of this hostile environment is remarkable, and yet, some plants and animals remained. one such survivor was Lystrosaurusfour-legged herbivorous, And now, more than 250 million years later, paleontologists have discovered two fossils of these tiny animals. Complete with mummified skin.

Description of this exciting discovery a. has been done in paper published in Paleogeology, Palaeolithic, Palaeolithic. Teagive that Lystrosaurus The fossils are among the 170 fossils from the Karoo Basin in South Africa studied in this paper. The Karoo is one of a handful of places in the world that records the boundary separating the Permian and Triassic periods, a boundary that includes the End-Permian Extinction Event (EPME) that caused most of the marine and marine life to exist about 252 million years ago. Terrestrial life was killed.

Lead author Roger Smith has been working there for 47 years. He is a Distinguished Professor in Institute of Evolutionary Studies of the University of the Witwatersrand and an Emeritus Research Associate Iziko South African Museum in Cape Town. He and his colleagues Jennifer Botha and Pia Viglietti studied an outcrop that is a known Lystrosaurus hot spot, has produced over 500 fossils. But for this paper, they focused on 170 tetrapod fossils—a term referring to four-legged vertebrates—all from a time known as the Induan era, which cover Million years after EPME. among many The fossils studied in this outcrop range from four to eight . group of Lystrosaurus The fossils were found together, with their bodies spread out, two of them preserving mummified skin.

That skin, Smith explained in a video callalmost matched his prediction: the animal had no hair, as evidenced by the lack of hair follicles, but it was not scaly, either. Noting that the scales are often not preserved, he compared it to the skin of an elephant: leathery but with dimples. “The idea that it was like a transitional fossil — between scaly and true hairs — stems from almost that skin texture,” he said.

Close-up of the texture of the pustular surface of annotated mummified skin.

Close-up of the texture of the pustular surface of annotated mummified skin.
photo, 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 larger than found in the TriassicBut it is also important to note that all Lystrosaurus The fossils so far discovered from the Triassic are of juveniles and sub-adults.

Cisneros compared the sizes of Lystrosaurus The EPME followed for a small pig and said it was “the largest land animal of the time. Everything that survived mass extinction was small.”

“Before the extinction,” agreed Smith, “was bigger and heavier and a ruminant trend. But afterward, it was no longer successful.”

underground digging is one of behavior supposedly helped Lystrosaurus Survived extinction and extreme heat after that event. But that is not all, and some other survival strategies include, if not inter-species cooperation, then at least inter-species tolerance. In one example, the author uses two different . point to the fossils of Lystrosaurus Species that died together indicate that these species may have foraged for food together rather than competing for it.

Sharing shelter with other contemporary species was another example. In three examples, several species including Lystrosaurus Long tubular burrows were found in association with casts, strongly indicating these animals sheltered and died together.

Within these ancient shared habitats, three species were four-legged reptiles. (Thrinaxodon, Gallasaurus 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 are finding more evidence “now that these dinosaur ancestors were not only able to live there, but they were able to diversify and become the dominant animal in the Triassic.” “The Rise of the Dinosaurs Is Beginning.”

While the causes of EPME continue to be debated, the authors draw on their work in the Karoo Basin to support the hyperthermic cause of the extinction, implying that a volcanic eruption in the Siberian Traps had devastating effects on Earth. 252 million years ago, an event that changed the seasons through volcanic emissions of greenhouse gases and acidic particles. This had disastrous consequences, including “vegetation die-off and drought (aridity with short and unpredictable periods over land), Smith explained, as well as “oxidation and acidification of the oceans.”

“We are now treating this as a Pangea-wide hyperthermal,” Smith, referring to the single continent that included the land on Earth at that time. “Therefore, episodes of Pangea-wide drought would be expected.”

This paper, he noted, is part of a larger project he and his colleagues are working on within the Karoo Basin: only one of many papers before it and other exciting papers to come.

Smith acknowledged, “there is still much to be resolved,” he believes, when he and his colleagues have completed their research on the Karoo Permo-Triassic limit (PTB) interval, they think that they will be recognized as a “locality type”. Terrestrial end to the Permian extinction event.”

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

Gene Timmons (@mostly mammoths) is a freelance writer based in New Hampshire who blogs about paleontology and archeology mostly,

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