A fossil found in New Mexico belongs to a new species of dinosaur. Courtesy | Twitter
A partial skull found in southeastern New Mexico belongs to a new species of Tyrannosaurus known as the Tyrannosaurus mcraensis, a dinosaur which according to scientists predates the T. Rex by seven million years. But Anthony Swinehart, professor of biology and curator of the D.M. Fisk Museum of Natural History, said there may be more to the story.
“It’s hard to be sure from just one specimen,” Swinehart said. “It may be that no other specimens are found, that most of the scientific community rejects it as a new species.”
The differences between the two dinosaurs lie “in the shape and the articulation of the skull bones,” with the T. mcraensis’s bone structure variations being completely distinct compared to the variations within the T. Rex species, according to an article published in Scientific Reports.
Swinehart said that some scientists disagree on the amount of dinosaur species that existed.
“Some of what we thought were new species were actually juveniles or something like that—their horns change a little bit as they develop,” Swinehart said.
Swinehart said that paleontologists are limited by the fossils they find.
“We can’t take tissue samples and do DNA and look at the number of base pair differences, but when you get into slight differences — where these things are really — it looks just like a T Rex, but this little thing is slightly different,” Swinehart said. “ Do we know, especially from one specimen, that that’s truly a different species, or could it be the same species that, because it lives in a different geographic location, has some slight variability?”
Abigail Snyder ’23, who graduated with a biology minor, said that any natural evidence found, whether for dinosaurs or for any scientific phenomenon, has multiple explanations and can support different points.
“If you set out to reach a certain conclusion, you probably can,” Snyder said. “There are so many variables in this world that you probably can convince someone that your side is right, just from the data. There’s data, and people say, ‘this is my view,’ and then you can also look at that same data and come to a completely different conclusion.”
Freshman Elizabeth Soeleman, who is interested in pursuing a biology major, says that this finding did not surprise her.
“There’s so much of the world that we have not discovered yet and so much that we still don’t know,” Soeleman said. “With each new discovery that I see on the internet, of course you have to be cautious about: is it true or is it just being made up?”
Swinehart said he was reminded of the Nanotyrannus and Tyrannosaurus Rex controversy, where the fossils of a small dinosaur that resembled the T. Rex were found and scientists argued about whether they had found a new genus or a juvenile T. Rex.
Having living tissue — such as cartilage — would have helped the debate, according to Swinehart.
“You can tell, oftentimes, if an animal is juvenile by looking at the bones to see if the epiphyses have fused like the knuckle on the end of a leg bone in an adult is actually fused,” Swinehart said. “There’s little cartilage in between —whereas for juveniles, you have the separate bone cap, a piece of cartilage, and then the rest of the bone.”
According to Swinehart, more evidence is needed to draw a conclusion. Despite the questions these new findings pose, he respects the scientists’s efforts in publishing.
“Publishing is a rigorous process,” Swinehart said. “I’ve published a lot, and it’s very time consuming and sometimes frustrating. The editor will pick experts in the field, too, and they make you go through a collection of extra data and rewrite this and that — it’s tough, but it’s important to publish.
Swinehart believes the scientists did the right thing in publishing their findings.
“But if these people that wrote this paper never published it, no one would be talking about it,” Swinehart said. “No one would be looking for additional specimens to either support or refute. There would be no conversation.”
