Parkside professor takes lead in naming dinosaur

From Journal Times: Parkside professor takes lead in naming dinosaur
SOMERS — The Cretaceous was hot and is hot again.

It was hot about 75 million years ago when a small dinosaur roamed what is now Utah. A team led by a University of Wisconsin-Parkside professor named this new species, which is one of the best specimens of its kind from North America before mammals rose to prominence and humans trod the earth.

It took about a year to name the new creature, said Lindsay Zanno. She is a 34-year-old assistant professor of biological sciences at Parkside and research associate at the Field Museum in Chicago. She is also the lead author of the Public Library of Science paper which named Talos sampsoni.

Talos was about the size of a big German shepherd, 80 pounds in weight and 5 to 6 feet long. And it was covered with feathers. The feathers are known from related dinosaurs found in China. Specimens there have been much better preserved, Zanno said, and one was an almost complete skeleton found in a sleeping position with its head tucked under its wing just like a modern bird.

Some of the Chinese specimens even have the remnants of feathers which scientists have been able to analyze to determine color, said Hans Sues, 55, a curator at the National Museum of Natural History, part of the Smithsonian Institution in Washington, D.C.

BIG FAMILY

What makes Talos such an exciting find is that it contradicts the idea that dinosaurs of the western, interior United States were uniform, Sues said. It is likely, in fact, that this part of the western U.S. was once a hotbed of dinosaur diversity.

"The world was very different than it is today," Zanno said. "There were no polar ice caps and global temperature was high. The oceans were expanding; they were basically flooding onto the continent and creating these very shallow seas."

In North America a shallow sea about 1,800 miles long stretched from the Gulf of Mexico to Canada and divided the continent into East America and West America, Zanno said. So Talos was essentially in a coastal environment that would have been lush, hot and humid. But the seas would also have been pressing against the beginnings of the Rocky Mountains and isolating the animals in this area.

"So there's a very dynamic evolution going on on the continent during this time. And we think that contributed to really high diversity and many different species living there because of the complex interaction because sea and the mountain. I mean, this area is one of the most diverse areas for dinosaurs anywhere in the world. We have a phenomenal number of dinosaur species from this one ‘island,'" Zanno said.

The large eyes of this group of dinosaurs give another clue to their lives, Sues said. They were probably chasing prey at dusk or during early evening, he said. There would have been plenty to eat: smaller dinosaurs, babies of larger animals, eggs, lizards, frogs, salamanders, even insects.

But diet is hard to pin down, Zanno said. Talos probably ate meat and some plants.

AND BRAINS, TOO

This group of animals also had, for dinosaurs, very large brains compared to the size of their bodies. They would not have been as intelligent as a comparable mammal, Sues said, but somewhere in the range between and ostrich and an eagle.

"Neither are intellectually brilliant, but they're certainly capable of complex behaviors," he said.

There is evidence on the Talos skeleton of a rough life. One of its toes was injured, perhaps from a fracture or perhaps a bite, but certainly from some high-risk activity, Zanno said. It lived with that injury for a few months to a year before dying at between age 4 and 6. Like trees, she said, scientists can determine a dinosaur's age by looking at a cross-section of fossilized bone and counting the growth rings.

Much as we may think of dinosaurs as fierce predators, Zanno said, it's important to remember these were living, breathing, complex creatures.

"Something like Talos would have been fierce only when he needed to be," she said. "I think all in all an animal like Talos would have strived not to be seen. And certainly when you're running around in an environment filled with tyrannosaurs, you want to strive not to be seen."

These tyrannosaurs were not the T. rex, still about 10 million years in the future from Talos, but dinosaurs of the same family weighing 2,000 to 4,000 pounds - enough to see a German shepherd-sized dinosaur as dinner.

LIMITED BONES
For all that Zanno and her team learned about Talos, it comes from only part of the animal. The group had the hips and legs and feet, some vertebrae and two forearm bones. And this makes it the best specimen found so far in North America.

The reason is that Talos was a small animal. The bones of a dead Talos would have been scattered by scavengers. And the bones themselves are like those of modern birds: thin-walled and hollow, meaning they could be easily broken or crushed.

Despite all the impediments to recognizing specimens from millions of years ago, dinosaurs are out of their ice age. New species are being announced every few weeks, Sues said, and instead of a few hundred species scientists now believe there were probably thousands of species of dinosaurs.

Far from being a fossilized field, the study of dinosaurs is picking up speed. That is why, in this time of polar ice, the Cretaceous is hot again.