Friday , November 27 2020

An incredible bird-dinosaur thrills the scientists after 25 years of museum storage



Illustration of the outline Mirece eatoni Sitting on Uttyceratops gettyi
Illustration: Brian Eng

A museum might amaze you with all its fossil specimens, but it's usually just a small part of what's there – specimens in the back can be placed in drawers or cast, wrapped in crates, quietly keeping secrets or more mysteries about the past. This is the case with amazing bird fossils, found 25 years ago in Utah but only described.

The fossils are pretty crazy – a bird the size of a turkey, called an antennae, probably capable of flying, and perhaps one of the most complete of its kind ever found in North America. This promotes the mystery of why some extinct but other dinosaurs (the birds we see today) are stuck around.

Clavicle
Photo: Atterholt et al (PeerJ 2018)

"The skeleton tells an interesting evolutionary story." Just before they were extinct, individual enantiornithine birds separately developed advanced flight adaptations just like modern birds, "author Jessie Atterholt, a professor at the Western University of Health Sciences, said Gizmodo.

This fossil has a story of a quarter of a century. The paleontologist Howard Hutchison found him on a trip to the Grand Stirks-Escalante National Monument in Utah, on 75-million-year-old rocks. Many paleontologists knew about the "important" specimen, Etherholt explained, but never completed their analysis. Ettrault was particularly interested in the development of this anantorenitin and asked if she could work on it. "Now we finally make it happen," she said. She, Hutchison and researcher Jaynmay O'Connor published the results today at PeerJ.

The fossil skeleton, now a new species called Mirarce Eatoni, Including a few vertebrae, the base of the spine supporting the tail feathers, almost all the bones of the left foot and the right, bone bone, femur, the lowest leg bone found in birds called tarsometatarsus, bone bone, and other pieces. It was a bird's look, and probably the size of a turkey. Perhaps the most exciting, the ultra, or bone bone, featured in small rough tendons interpreted as "feathers and handles". These are the current features of today's birds that strengthen the feathers attest to advanced flight, said Atterholt.

Pieces of left foot
Photo: Atterholt et al (PeerJ 2018)

"There is no doubt that this is one of the most important bird fossils from the dinosaur era," said Steve Brustata, a paleontologist at the University of Edinburgh who was not involved in the study.

This fossil tells the story of a group of birds that developed in parallel with the precursors of today's modern birds, but did not undergo the mass extinction event. The high level of the extra preserved detail demonstrates that a ton of diversity has not been able to make it beyond the asteroid strike. But it deepens the mystery. After the meteor, only a few birds survived, which then diversified into 10,000 species around the day. Brostat spelled out the mystery:

"Maybe they had beaks and could eat seeds – a nutrient source that could survive in the soil for decades or centuries, a food bank in case the world went to hell when the asteroid hit, or maybe these birds nest on the ground so they were not wiped away with the birds living in the trees when The forests collapsed after the asteroid hit, or maybe they can fly more, or grow faster, or hide more easily, but we do not really know, but this new discovery tells us that the birds that lived with the last dinosaurs were even more diverse than we used to think, More mystery why few of them survived the asteroid. "

All the bones were found
Illustration: Scott Hartman

Atterholt continues to explore these bones to learn how the bird was and how it evolved. She also mentioned the recent controversy over the site from which the fossil originates, the Grand Staircase Escalante. Recently, President Trump have reduced the size of the national monument. She pointed out that such decisions could end such discoveries.

"This material will be in danger of destruction and the threat of reducing the size of the protected lands."

[PeerJ]

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