T is for T. rex

Feathered TRex from Everything Dinosaur blog (2018)

Mr. T!

Why wasn’t in named T. regina? (Tyrannosaurus regina, Queen of the dinosaurs?) I suppose that’s a pipe dream. Consider who discovered them first and named them first. Women weren’t in charge of naming at the time.

He was a formidable guy. And there were a lot of him around, as the world seems to be full of many T. rex and general tyrannosaurus species specimens. They’re finding them practically every year out in the deserts of China and Montana. T. rex is arguably the most popular dinosaur, the best known. Plus, people love to make fun of those tiny arms.

1905 version of the skeleton.

The History of the Finding

The first person to find T. rex fossils was named after P.T. Barnum, circus showman, which seems appropriate. His name was Barnum Brown, and he was the new naturalist running the brand spanking new American Museum of Natural History in New York. They had a bit of funding, so Barnum was out in the west digging for bones. And he found them.

Barnum was known to pay “good money” for any kind of interesting specimen, but he also put in his time in Hell Creek, Montana, searching for specimens for the museum. In 1902, his team found a piece of what they called a large “carnosaur” — meat-eating lizard. Then, they found another. Lots of eight inch long spikes, which theybfiund were teeth from a giant jaw. By the time they had dug out the 30+ bones, they knew they had a massive reptile skeleton that the New Yorkers would flock to see. Barnum’s boss, Henry Osborn, chose the name.

Tyrant-lizard is the genus name–tyrannosaurus is just one of the tyrannosoids. Rex being the king of all. One of the original skeletons went to London, and the other was sold to the Carnegie Museum (see letter “D” again).

Those would be the only T. rexes found for a while, as the Depression and war put a halt to the rage for fossil-hunting. For a while.

Sue, Stan, Scotty, and the Rest

But as the last few decades have been a renaissance for dinosaur hunting in general, the last century has seen the finding of many more carnosaur skeletons. Even in the 21st century, paleontologists have dug up one skeleton after another. Frequently, they have been given first names.

One of the most famous, Sue, who graces the hallway of the Field Museum in Chicago, was named for amateur fossil hunter Sue Hendrickson. Hendrickson found what turned out to be 85% of a T. rex, also in the Hell Creek formation. Although amateur here sounds pretty– means “without a Ph.D.”

The famous Chicago “Sue,” photo by kajmeister the cheapskate.

Sue became so famous, so quick, that she was the subject of a legal battle–Sue the dinosaur, that is. After several years of wrangling over what would become clearly a large money-maker, the settlement was in favor of the the person who owned the land on which Sue’s skeleton was found. No doubt, though, the $7.6 million that the Chicago museum paid for Sue will be earned back many times over, as Sue is more popular than stuffed pizza. I have my own blurry photograph, taken from outside the museum gates–I only had 10 minutes, so I didn’t want to pay the $50 to get closer.

Now, the largest T. rex found so far ended up in Japan. He was named Scotty, and it took the dogged paleontologists nearly 20 years to pull out the bones. Under the circumstances, he certainly deserves his own personal name, to add to the genus and species.

“Scotty” In Japanese museum.

The Tiny Arms Thing

We should get the tiny arms business out of the way. I wrote about it once before ( 3 years! so long ago!), but I’ll recap it briefly. The arms of the T. rex are a kind of proof of the nature of how adaptation works, a la Darwin. Humans think the arms are ridiculous because, to humans, arms are vital. But, to T. rex, they were a bit unnecessary, and in fact a tradeoff.

Attaching arms to the frame requires a lot of muscle and brain capacity to be used for directing their function. Assume that goes away. Then, the brain can be used for other things, like highly developed senses. Plus, if you don’t need muscles for arms, then there can be more muscles to attach to the jaws. The head, the jaws, the teeth can all be that much bigger and more powerful.

Who needs arms, when the jaws do double-duty?

T. rex supposedly had the strongest bite power of any creature (known, studied, discovered etc etc). It did so because it didn’t use the muscles for unnecessary things, like arms. Besides, the paleontologists think the arms were quite good at disemboweling whatever creature Mr. T’s jaws had partly crunched.

Tastes Like Chicken

We should probably get the feathers thing out of the way, too. Birds are dinosaurs; they evolved and emerged from the line of theropods that created most of the meat-eaters. Chickens are closer to T. rex than T. rex is to a stegosaur.

It would be fascinating to think–or to know–that T. rex really did have feathers. But there have never been found any fossils that show feather impressions. A few years ago, some tyrannosoid fossils in China had something. They suggested that the skin might have had those proto-feather filaments. Once a few scientists wrote up a proposal, the Internet then decided that the question was concluded. T Rex had feathers, according to the Dino enthusiasts, and now there are dozens of painted variations of our feathered friend.

But the scientists are still arguing and looking for evidence. If rex had feathers, they weren’t for flying, but rather for warmth (or cooling) and for display. And the paleontologists jury is still out. They’ll keep looking. They’ve found so many bits already, surely there must be a feathered rex fossil imprint waiting to be discovered.

The Japanese museum even has a circle of Rex heads. Half a dozen antorbital fenestrae.

The Tough Life of a Predator

What the fossils do show, however, is a lot of wear and tear. Sue’s skeleton, according to Kristi Curry Rogers, “is riddled with problems.” Three broken ribs, broken arm and shoulder, and oddly healed joints all down the left side. She may have been attacked or fallen down a deep hill. But she was alive when it happened and lived years after.

How can they tell that dinosaurs had healed broken bones? They can tell from the way that the bones have lumps, scratches, or irregular pieces, where the bones might have been broken and then grown back. Even grown back while the animal was constantly in motion, so that the growth was at odd angles.

Maybe the T. Rexes did have an 8,000 pound bite and 60 teeth, each as long as your hand. But they fought with each other, and they lost perhaps as much as they won. The rex wikipedia entry has a section in tyrannosoid cannibalism. Not an easy time of it.

Reminds me of the old college days. Photo from UCB Paleontology.

When I was in school, so many many years ago, I would cut through the life sciences building on my way through campus (during the rain? better snacks? can’t remember why…) and I remember passing by a T. rex skull, just sitting on a table, behind a glass next to a wall. It was longer than I am tall. Perhaps that’s why I’m so nostalgic about him now. This photo also belongs to Berkeley, but it was found in 1998, so that’s not the one I’m remembering.

The world has so many T. rex skeletons, and yet somehow one can never look at them enough without wondering something else. Did they have lips? Probably not, though that generated another study, with graphs and words I cant pronounce. Could they see red? Yep. Were the ladies bigger or smaller? They’re not sure. They know there were lady T. rexes because there are bone cell markers related to egg storage. Could they run fast? Not as fast as a jeep. If you were agile enough, say the stories, you could get away.

I would not want to find out if I am agile enough.

4 Replies to “T is for T. rex”

  1. One day, they’re going to figure out that, as T-Rex was a predator, its eyes would be on eyestalks, or at least raised eye-sockets, maybe even to allow for swivelling eye movement to see prey as it moves in peripheral vision. Prey typically have eyes to the side – so when I see the recreations of predator dinosaurs, I wonder if those like T-Rex, drawn with eyes on the side of their head, are really prey?
    Not with those teeth, surely, so why get the eyes so wrong?

    1. Excellent point, and one where some get it wrong and some don’t. If you look at my tiny arms drawing, or reference this article here: https://www.sciencenews.org/article/sight-saur-eyes-t-rex-vision-was-among-natures-best, they explain that T rex’s eyes sat in front of grooves above its mouth. That allowed the eyes to see sideways and forward, definitely better than most birds and better than people. I don’t know about the eyestalks, but supposedly the eyes were positioned in a way to make it an excellent predator.

      Now, the drawing at the very top of the blog, I agree. Not really showing those grooves in front of the eyes. That painting makes it look like they needed eyestalks. From now on, I am going to judge those T rex drawings based on the quality of the eyeballs. Thanks for the comment!

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