Scientists Say 'Dueling Dinosaurs' Fossil Confirms a Smaller Tyrannosaur Species, Not a Teenaged T. Rex (npr.org) 9
An anonymous reader shared this report from NPR:
It's known as the "Dueling Dinosaurs" fossil: A triceratops and a tyrannosaur, skeletons entangled, locked in apparent combat right up until the moment of their mutual demise... That discovery in 2006 now appears to have overturned decades of dinosaur dogma about Tyrannosaurus rex, the fearsome giant long thought to be the sole top predator stalking the late Cretaceous. In a paper in the journal Nature, paleontologists Lindsay Zanno and James Napoli conclude that some of the bones from that specimen belong not to a teenage T. rex, but to a fully grown individual of a different tyrannosaur species — Nanotyrannus lancensis....
One of the first of those red flags in the new specimen was the arm bones. They looked completely different than T. rex's puny appendages... "These are powerful arms with large claws, large hands. They were using them for prey capture." Contrast that with T. rex, "an animal that's a mouth on legs." There were additional clues. The animal had fewer tail vertebrae and more teeth than T. rex. Zanno and Napoli considered other lines of evidence. They created 3D models of numerous purported T. rexes against which they compared their specimen. They looked at the growth stages of the cranial nerves and sinuses of close living relatives of dinosaurs, features that were visible in the fossilized skeleton.
"But maybe the most important and damning thing that we did was we were able to figure out that our animal is not a juvenile at all," she says. This conclusion was based on slicing through the fossil's limb bones to examine the growth rings. That work demonstrated that this animal was mature and done growing when it died around the age of 20. "That means it's half the size and a tenth of the mass of a full grown Tyrannosaurus rex," says Zanno... In addition, while making models of all those other alleged T. rex skeletons, Zanno says they identified another new species of tyrannosaur, one they're calling Nanotyrannus lethaeus...
"It tells us that these end-Cretaceous ecosystems right before the asteroid hit were flourishing," says Zanno. "They had an abundance of different predators. And refutes this idea that dinosaurs were in decline before the asteroid struck."
One of the first of those red flags in the new specimen was the arm bones. They looked completely different than T. rex's puny appendages... "These are powerful arms with large claws, large hands. They were using them for prey capture." Contrast that with T. rex, "an animal that's a mouth on legs." There were additional clues. The animal had fewer tail vertebrae and more teeth than T. rex. Zanno and Napoli considered other lines of evidence. They created 3D models of numerous purported T. rexes against which they compared their specimen. They looked at the growth stages of the cranial nerves and sinuses of close living relatives of dinosaurs, features that were visible in the fossilized skeleton.
"But maybe the most important and damning thing that we did was we were able to figure out that our animal is not a juvenile at all," she says. This conclusion was based on slicing through the fossil's limb bones to examine the growth rings. That work demonstrated that this animal was mature and done growing when it died around the age of 20. "That means it's half the size and a tenth of the mass of a full grown Tyrannosaurus rex," says Zanno... In addition, while making models of all those other alleged T. rex skeletons, Zanno says they identified another new species of tyrannosaur, one they're calling Nanotyrannus lethaeus...
"It tells us that these end-Cretaceous ecosystems right before the asteroid hit were flourishing," says Zanno. "They had an abundance of different predators. And refutes this idea that dinosaurs were in decline before the asteroid struck."
Re: (Score:2)
If you consider that one lineage resulted in birds, and chickens are birds, then maybe some tasted like chicken. Or you can check out crocs.
Re: (Score:2)
Yeah, dinos ruled the earth for hundreds of millions of years... then basically evolved into chicken nuggets.
Maybe homo sapiens will have a similar fate - due to online life and lack of physical activity we'll evolve into a nice limbless brain snack for some future species to factory farm?
IKnowDino (Score:4, Interesting)
There's a couple of dino enthusiasts who have a popular podcast who talked about this recently. It was a good discussion, and pretty much tracked with this. As they pointed out, the real controversy is the "And refutes this idea that dinosaurs were in decline before the asteroid struck" part. There are partisans on each side of the "dinos were dying out anyways" hypothesis, so it's another data point for the "uh-uhh" side. I imagine this will continue for a while.
Anyways, interesting work for those of us interested in such things.
Tyrannosaurus rex (Score:1)
Speaking of dinosaurs with tiny hands [youtube.com].
Deuling dinosaurs (Score:3)
Re: (Score:2)
Here's a picture of what the fossil looked like [wikipedia.org]. It was found in 2006. They were not necessarily fighting each other when they died, it could be that's just how their bodies landed.
Yeah so rude for the poor dinosaurs, maybe they were having sex.
Anyway, I would have called them the "Lovers Dinosaurs" which is much more respectful for those poor peaceful gentle creatures which for some reasons we always paint as violent.
Re: (Score:2)
I blame Gene Roddenberry for the untold damage to the reputation of lizard people via TOS episode Arena.
The Gorn were living their best lives until the Metron showed up and tried to provoke a conflict with Captain Kirk.
Re: (Score:3)
Apparently there are teeth from the Nanotyrannus embedded in the spine of the Tricerotops, and the former has a cracked skull.
https://www.theguardian.com/sc... [theguardian.com]