Birds evolved from dinosaurs. They share a common ancestor and physical traits — some dinosaurs even had feathers. But while these dinosaurs are thought to have had “fuzzy” or “downy” feathers, ancient birds were more likely to have had feathers that look similar to the birds of today.

A ÂÒÂ×ÉçÇø-led research team has discovered the best-preserved fossil feathers from the — in a fossilized dinosaur poop, also known as a “coprolite.” Some of these feathers have features that look like modern birds’ feathers. In in Current Biology, the team describes this finding and how it can help researchers better understand why and how some birds survived the that killed 75% of life on the planet.

The team discovered the feathers in 2016 at a research site in eastern Montana in the badland exposures of the geological formation called the .

“I was crawling up a rocky outcrop collecting fish fossils when I came across a dark, reddish-brown nodule about half the size of a golf ball,” said co-author , a UW research scientist in the biology department and the Hell Creek Project collections manager at the Burke Museum. “I picked it up and scanned its surface through my hand lens, and that’s when I couldn’t believe what I was seeing: a tiny fossil feather. I was cautiously optimistic about its discovery, because feathers had not yet been found in the Hell Creek Formation, even after more than 100 years of prospecting.”

Back in the lab, the researchers examined the specimen’s mineral composition and took CT scans of it — essentially, thousands of X-rays that are digitally stacked to reveal the contents of an object.

“Every hour processing the data revealed another feather, another scale, another bone — in stunning 3D,” said co-author , a paleontologist at the Carter County Museum.

The coprolite contained multiple feathers, tiny fish scales from a gar and leg bones from a , an extinct group of birds that are ecologically similar to loons. The researchers reasoned that the feathers must have also come from this same bird. These are the first hesperornithiform feathers ever found.

The hesperornithiforms are close cousins of the birds that survived the mass extinction and still live today. Some scientists have hypothesized that the birds that survived did so because they lived near water, and something about this habitat helped buffer them from the effects of the mass extinction. But the hesperornithiforms also lived by water, and they went extinct.

“We think the types of feathers that these birds had, and/or the way they molted those feathers, may have been one of the underlying causes of the selectivity of the end-Cretaceous mass extinction — essentially, why some birds died out and why others survived,” said lead author , associate curator of fossil reptiles at the Field Museum. “Some of these diving birds’ feathers seem to have been modern-looking and waterproof, but they also had some smaller fuzzy, primitive body feathers that we associate with dinosaurs.”

If the feathers on hesperornithiforms and other extinct bird species weren’t as good at keeping their bodies warm, the researchers hypothesize, maybe that’s why they weren’t able to survive the extinction event.

“It’s such a beautiful, well-preserved feather, from such an unexpected source, and it’s exciting that it could help us answer this huge question in paleontology,” O’Connor said. “I usually work with fossils that are preserved in big stone slabs, and the entire skeleton and even the soft tissue is preserved — they make it easy for me. But with this project, we just had this coprolite — and its contents — to go off of, and it made me feel like a detective, piecing together all these little clues. And since no one has studied feathers in coprolites before, this opens up a whole new avenue for investigation. We only knew to look at this one because of how it happened to be split open, with the feather exposed — it was literally a lucky break. I hope more scientists start CT scanning coprolites and taking a closer look at them to see what might be inside.”

, UW doctoral student in biology; , the Hell Creek Project Fossil Preparator at the Burke Museum of Natural History; at the University of Colorado, Boulder; at the Field Museum and the University of Chicago; Christian Cooper at the Field Museum; at the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences; at the University of Alabama; at the Natural History Museum of Los Angeles County; at the University of Southern California; and at the Natural History Museum of Los Angeles County are also co-authors on this paper. This research was funded by donations to the Hell Creek Project.

For more information, contact Wilson Mantilla at gpwilson@uw.edu and DeMar at ddemar@uw.edu.

Adapted from .

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Paleontologists picking through a bounty of fossils from Montana have discovered something unexpected — a new species of lizard from the late dinosaur era, whose closest relatives roamed in faraway Asia.

This ancient lizard, which lived 75 million years ago in a dinosaur nesting site, is described from stem to stern in published Jan. 25 in the . Christened Magnuviator ovimonsensis, the new species fills in significant gaps in our understanding of how lizards evolved and spread during the dinosaur era, according to paleontologists at the ÂÒÂ×ÉçÇø and the who led the study.

“It is incredibly rare to find one complete fossil skeleton from a relatively small creature like this lizard,” said , lead author and postdoctoral research associate in the UW biology department and the Burke Museum. “But, in fact, we had two specimens, both from the same site at Egg Mountain in Montana.”

Right out of the gate, Magnuviator is reshaping how scientists view lizards, their biodiversity and their role in complex ecosystems during this reptile’s carefree days in the Cretaceous Period 75 million years ago.

Based on analyses of the nearly complete fossil skeletons, Magnuviator was an ancient offshoot of iguanian lizards — and they’re actually the oldest, most complete iguanian fossils from the Americas. Today, iguanians include of the Old World, and in the American tropics and even the infamous water-walking — or “Jesus Christ” — lizards. But based on its anatomy, Magnuviator was at best a distant relative of these modern lizard families, most of which did not arise until after the non-avian dinosaurs — and quite a few lizards and other creatures — went extinct 66 million years ago.

The team came to these conclusions after meticulous study of both Egg Mountain specimens over four years. This included a round of CT scans at Seattle Children’s Hospital to narrow down the fossil’s location within a larger section of rock and a second round at the American Museum of Natural History to digitally reconstruct the skull anatomy. The fact that both skeletons were nearly complete allowed them to determine not only that Magnuviator represented an entirely new species, but also that its closest kin weren’t other fossil lizards from the Americas. Instead, it showed striking similarities to other Cretaceous Period iguanians from Mongolia.

“These ancient lineages are not the iguanian lizards which dominate parts of the Americas today, such as anoles and horned lizards,” said DeMar. “So discoveries like Magnuviator give us a rare glimpse into the types of ‘stem’ lizards that were present before the extinction of the dinosaurs.”

But Magnuviator‘s surprises don’t end with the Mongolian connection. The site of its discovery is also eye-popping.

Egg Mountain is already famous among fossil hunters. Over 30 years ago, paleontologists discovered the first fossil remains of dinosaur babies there, and it is also one of the first sites in North America where dinosaur eggs were discovered.

“We now recognize Egg Mountain as a unique site for understanding Cretaceous Period ecosystems in North America,” said senior author , UW associate professor of biology and curator of paleontology at the Burke Museum. “We believe both carnivorous and herbivorous dinosaurs came to this site repeatedly to nest, and in the process of excavating this site we are learning more and more about other creatures who lived and died there.”

The team even named their new find as homage to its famous home and its close lizard relatives in Asia. Magnuviator ovimonsensis means “mighty traveler from Egg Mountain.”

Through excavations at Egg Mountain led by co-author at Montana State University and meticulous analysis of fossils at partner institutions like the UW and the Burke Museum, scientists are piecing together the Egg Mountain ecosystem of 75 million years ago. In those days, Egg Mountain was a semi-arid environment, with little or no water at the surface. Dinosaurs like the duck-billed and the birdlike, carnivorous nested there.

Researchers have also unearthed fossilized mammals at Egg Mountain, which are being studied by Wilson’s group, as well as wasp pupae cases and pollen grains from plants adapted for dry environments. Based on the structure of Magnuviator‘s teeth, as well as the eating habits of some lizards today, the researchers believe that it could have feasted on wasps at the Egg Mountain site. Though based on its relatively large size for a lizard — about 14 inches in length — Magnuviator could have also eaten something entirely different.

“Due to the significant metabolic requirements to digest plant material, only lizards above a certain body size can eat plants, and Magnuviator definitely falls within that size range,” said DeMar.

Whatever its diet, Magnuviator and its relatives in Mongolia did not make it into the modern era. DeMar and co-authors hypothesize that these stem lineages of lizards may have gone extinct along with the non-avian dinosaurs. But given the spotty record for lizards in the fossil record, it will take more Magnuviator-level discoveries to resolve this debate. And, unfortunately, part of the excitement surrounding Magnuviator is that it is a rare find.

Other co-authors are the late Jack Conrad of the New York Institute of Technology and the American Museum of Natural History and of the University of Cambridge. The research was funded by the National Science Foundation and the American Museum of Natural History.

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For more information, contact DeMar at ddemar@uw.edu or 206-543-4832 and Wilson at gpwilson@uw.edu or 206-543-8917.

DOI: 10.1098/rspb.2016.1902

Grant numbers: 0847777, 1325674.

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