AUSTIN (KXAN) – A recent expedition to Patagonia by researchers from the University of Texas may give us a better understanding of the last days of the dinosaurs.

Fossils, including those of a Megaraptor, were found in the dig. The species existed between 66 to 75 million years ago in the Late-Cretaceous period, shortly before the species was killed off.

Sarah Davis, Ph.D., was the lead author of the paper published last month in the Journal of South American Earth Sciences. Professor Julia Clarke of the UT Jackson School of Geosciences led the expedition, which began in 2017.

Among the fossils found were the Megaraptor, a 25-foot long theropod that was one of the top hunters in the area. “Mega Raptors have three fingers and these really, really dramatic claws,” Davis said.

Others include the unenlagiines, a chicken-sized species covered in feathers, and two bird fossils, the enantiornithines and ornithurines.

The enantiornithines resembled sparrows, but had teeth in their beaks. While the ornithurines looked a lot like modern day ducks or geese.

A time averaged artist’s interpretation of Patagonia during the Late Cretaceous, about 66-78 million years ago. The animals pictured include non-avian dinosaurs, birds and other vertebrates that have been discovered in the fossil record of the region. Their specific identifications are as follows: ornithurine birds (flying and walking on the ground), Stegouros (armored dinosaur), Orretherium (mammal), Yaminuechelys (turtle), a megaraptorid (large carnivore), unenlagiines (pair of carnivores), and enantiornithine birds (in foreground). Credit: Mauricio Alvarez and Gabriel Diaz.

Understanding the conditions of the species during their final days, Davis said, can help scientists better understand the ecosystem at the time.

One theory they’re investigating involves birds and mammals seeking refuge in Patagonia when the asteroid hit. Davis said studying these bones can help investigate this theory.

Going back to “Jurassic Park”

The species found existed around the same time as some of the most famous species from the most famous dinosaur movie: triceratops, velociraptors and of course the tyrannosaurs rex.

“This is a Tyrannosaur tooth,” Davis said as she showed us a shiny, black tooth from UT’s fossil collection. “This is very similar in just superficial appearance to what we were finding in the field for these Megaraptors.”

Teeth and toes were recovered from the Patagonia dig. Credit: Sarah Davis

Teeth and toes are easier to find in the field because of their shiny surface. “it’s still very shiny from that enamel surface.”

The team also found tiny bones from the birds, which are Davis’ specialty. “The frustrating but also interesting thing about Megaraptors is we don’t have a lot of skeletal material.”

A closer look at the expedition

Patagonia, where the expedition took place, is the southern tip of South America. The mountains of Chile, where the team hiked and camped for weeks on in, is a desolate place. There are no trees, just grass land. It is cold and rocky.

But 66.7 million years ago, when the mass extinction event took place, it was a temperate forest. Hence, bigger dinos in the area.

While Davis was looking for smaller fossils, other members of the team were looking for things like Long Neck. They found vertebra up in the mountains, but getting them down wasn’t easy.

UT Researchers began the expedition into the Chilean mountains in 2017 in search of dinosaurs. Credit: Sarah Davis

“We wrapped them up, got them all protected. And then we put them in bags and carried them off this mountain because we were up really high and like across a couple of rivers.” Davis said.

“I think we carried them five miles to get back to camp before we could actually then drive them out. So it’s a lot of hard work. You really get your strength training and your endurance training.”

Once the fossils reached camp, they could be carried out on ATVs and Trucks.

Uncovering the fossils and studying them

Fossils are wrapped up in whatever the team has available before they’re transported. The samples they recovered will remain in Chile. Others, like many fossils found in Texas, are brought to UT’s Vertebrate Paleontology Laboratory.

“The collections have been in use for over 100 years,” Davis said.

As these packages are delivered, the fossils wrapped up inside must be revealed.

“When you get a fully articulated fossil, it’s not beautifully prepped out. You then have to bring it into the lab and clean all the sediment and dirt off of it, find the bones in the matrix, and then glue them back together,” Davis said.

By examining and reassembling the fossils, Davis said they hope to better understand the last days of the dinosaurs. “Its a very, very dirty job, but its fun.”

Researchers from the University of Chile, Major University, the University of Concepción and the Chilean National Museum of Natural History also participated in the expedition.

It was funded by the National Science Foundation, the National Agency for Research and Development of Chile, and the Jackson School of Geosciences.