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A new study published in the journal Plus one Explores the weight of fossil sites on our understanding of the evolutionary relationships between fossil groups — Cumulative effect — and for the first time, assessed the power of these sites in our understanding of evolutionary history. Surprisingly, the authors discovered that wind-blown sand deposits of the Cretaceous Gobi Desert contain an exceptionally diverse and well-preserved fossil lizard record of their evolutionary history more than any other site on the planet. shape our understanding of

While famous as the area where Velociraptor Discovered, the Late Cretaceous Gobi Desert of China and Mongolia may have a major impact on our understanding of ancient — and modern — life thanks to its rich record of fossil lizards.

“What’s great about these Late Cretaceous Gobi Desert deposits is that you get a very diverse, extraordinarily complete, three-dimensional, and very diverse, and very well-defined, three-dimensional image,” said Dr. Hank Woolley, lead author and NSF Postdoctoral Research Fellow at the Dinosaur Institute. But preserved lizard skeletons are being found.” “You find many sequences on the squat tree of life represented by this single unit, giving us this remarkable fossil signal of biodiversity in the rock record, a lighthouse in the deep darkness of evolutionary history. stands out as”.

More complete skeletons make it easier to trace relationships over time by making it easier to compare similarities and differences. The more complete a skeleton is, the more traits are preserved, and those traits translate into phylogenetic data — data used to build the tree of life. “Where there is extraordinary conservation — hundreds of species from one part of the world in a given period — you don’t necessarily have a good idea of ​​global signals,” Woolley said. “It’s putting its thumb on the scale.”

To measure how unusual fossil preservation deposits (known in the paleontological community by the German term “Lagerstatten”) bear on a broader understanding of evolutionary relationships over time, Woolley and co-authors including Dr. Nathan Smith, Curator of the Dinosaur Institute. Combed through published records of 1,327 species of non-avian theropod dinosaurs, Mesozoic birds, and fossil squamates (the group of reptiles that includes mosasaurs, snakes, and lizards).

The fossil metanarrative

When it came to squamates, the researchers found no correlation between sampling intensity and whether any site affected the global phylogenetic data. Instead, they got a clue collecting environment, Different types of sites where sediments are deposited clearly preserve different groups.

Because the squamate record of the Gobi Desert is so complete, it shapes our understanding of squamate evolution globally and over time, an important example of the “lagerstätten effect” — even though it is a Not a typical lagerstätte. Traditional lagerstätten deposits come from marine chalks, salt lakes, and ancient lake environments — not dry sand dunes. Ancient environments shape what is preserved in the fossil record. “We didn’t expect to find this detailed record from lizards in desert sand dune deposits,” Woolley said.

“We often think of lagerstätten deposits as preserving soft tissues and organisms that rarely fossilize, or particularly rich numbers of fossils. both of them An unusually complete skeleton, and a high diversity of species from all the family trees of the group,” Smith said.

“We are at the border between fields within paleontology that rarely overlap: inferring the evolutionary relationships of fossil groups (phylogenetics) and inferring how things become fossilized (taphonomy). “Exploring the frontier will help add the Earth’s endangered biodiversity to museum collections. Link the past together.” Woolley said.

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