As promised, the Tyrannosaurus Versus Sperm Whale blog is branching out from whales to… Tyrannosaurs. Predictable? Perhaps.
You see, my sister’s birthday is coming up, and I’m more grateful than ever that she’s just the way she is. Because if she’d been born a Tyrannosaurus, I’d be screwed.
I’d always suspected that having a T. Rex sibling would be bad news, but now I know it. Paleontologists have shown that young Tyrannosaurs bite each other. Hard. The findings are available in the November issue of Palaios.
In 2001, a group of Northern Illinois University researchers dug up a juvenile T. rex in the Hell Creek rock formation in Montana. There aren’t many juveniles in the fossil record, so the team was excited just to find a young Tyrannosaurus in decent shape. Then, three or four years ago, closer inspection revealed some unusual holes in the skull.
The team determined that only another juvenile T. rex could have inflicted the injuries.
The holes happen to be the size and shape of the teeth of a young T. rex. Also, the skull warps to the left, starting at the bite marks. It’s the result of asymmetrical healing. It’s the dinosaur equivalent of a boxer’s nose, said Joe Peterson, an NIU Ph.D. candidate in geology and lead author of the study.
From the NIU website
Bones deform during fossilization, but the researchers knew that the bending wasn’t due to the fossilization process. If it was, Peterson said, it would have been “a lot more bent than it is.”
The team named the dinosaur Jane after a museum donor, although they haven’t been able to determine its sex.
Some T. rex relative skulls bear fight marks like Jane’s, but this is the first time this type of injury has shown up on a juvenile.
When dinosaur relatives like crocodiles and birds* fight members of their own species, Peterson said, they do so for one of three reasons: mating privileges, territory, and dominance. Jane was too young to be fighting for over a mate, he said. Jane died when she was only 11 or 12, and Tyrannosaurs hit puberty around age 14. The need for territory or social dominance are therefore probably behind the fighting, Peterson explained.
The team isn’t sure what Jane died of, but it wasn’t the result of the facial injuries. One very speculative explanation is that an infection in a toe bone could have caused a limp, possibly preventing Jane from catching food, Peterson said.
*Birds aren’t dinosaur relatives so much as descendants. Put another way, phylogenetically speaking, birds are dinosaurs.
Hilarious, informative and relatively kind to your sibling. I love it. The dinosaur’s equivalent of “boxer’s nose” is a natural follow to squid-eating whales, but hardly predictable.
Sweet. What can you possibly talk about for tomorrow? More whales? I think you should talk about giant sloths, another great and terrifying extinct animal.