D. Edward Malinzak has been working with an international team of researchers on fossil analysis since he was in graduate school. Now an assistant teaching professor of biology at Penn State Lehigh Valley, he has a new species of dinosaur to add to his list of discoveries.
“This, I believe, was a specimen that had been collected that had been identified and lumped in with another dinosaur, referred to as Kritosaurus. And in this case, we decided to take a look because our main questions were wondering about if this was sort of an over lumping of organisms.”
A closer look at fossils from New Mexico confirmed the team’s hypothesis that the diversity of dinosaur species in what is now the southwest United States was greatly underestimated.
Malinzak’s team discovered differences from other species primarily in the animal’s skull.
“In terms of the entire organism, the skull is very much your big ticket item. It’s the equivalent of having a piece of pizza that’s packed to the top with toppings versus one that’s got a tiny bit of sauce and mainly crust.”
The size of the animal’s skull alone told the team a lot about how it compared to other specimens, as well as how it may have processed food. Malinzak also noticed differences in the ankle. Although the team doesn’t fully understand yet how that difference plays a distinct role, it could tell them more about how the animal moved and interacted with its environment.
Fortunately for the team, they had more than one specimen to analyze. Although none of their specimens were complete, one had large portions of the skull intact, while another had pieces of limbs and ribs.
“We recover specimens and, very frequently, they’re not fully preserved. You could see it in films and movies where they’ve got the whole skeleton laying out there that they just dig up in the ground, and that’s usually not how it happens. You very often have very fragmentary pieces of a single individual. In our case, it was really lucky that we had the other associated specimen to really give us a full picture of the organism.”
The newly identified species is part of the herbivorous duck-billed hardrosaurid family. The Ahshislesaurus wimani, as it’s now been named, tells a story of dinosaur migration across North America. Part of a larger group of dinosaurs, the species spread from New Mexico to Canada, Central America, and South America.
This discovery leads to more hypotheses, Malinzak explained, about what changes the environment may have been experiencing, what may have caused some of these changes, and how animals interacted with the shifts.
Malinzak has been able to integrate these findings as they were happening into his Penn State classes, bringing students along on the journey with the team.
“I think a lot of the students enjoyed that aspect of getting to see it outside of just a textbook and a quick analysis; to really see the nuts and bolts of how these analyses come into play.”
The team of researchers, which features members from Montana, New Mexico, Pennsylvania, and the Slovak Republic, is continuing to look at fossils that could reveal more details about evolutionary relationships. They hope it will also pinpoint exactly when species like the Ahshislesaurus wimani lived.
Future discoveries, like this one, will likely come from hypotheses the team has already formed, rather than from surprise revelations. Confirming an existing theory is more exciting than finding surprises, anyway, says Malinzak.
“Because I know everyone wants to have the, ‘Oh, it was brand new! I can’t believe this happened!’ And it’s great to have that moment, but with me it was more of, ‘This fits what we expect.' It’s bearing out that these questions we’re asking, this data we’re getting, it’s leading to a better picture of what we had.”
