The Tyrannosaur Thread- Anything T. rex or tyrannosaurid related

Scotty is now on display at the Royal Saskatchewan Museum:

https://www.ctvnews.ca/canada/world-s-largest-tyrannosaurus-rex-scotty-unveiled-in-saskatchewan-1.4428084

https://regina.ctvnews.ca/scotty-the-t-rex-roars-into-royal-saskatchewan-museum-1.4427081

"Family group" find suggests tyrannosaurs (or some of them at least) may have been social animals:

https://www.ksl.com/article/46580183/tyrannosaurus-a-social-creature



Note that this story is being repeated by the media as if concerning Tyrannosaurus itself, but the find is from the Kaiparowits fossil site, which predates Tyrannosaurus by several million years.

The tyrannosaurid previously found at this site is the smaller but closely related Teratophoneus ("monstrous murderer") which may or may not be ancestral to Tyrannosaurus proper.

Possible tyrannosaur track found in China:

http://www.xinhuanet.com/english/2019-07/29/c_138267706.htm

http://www.uua.cn/show-10-9726-1.html



The track is seemingly the right size and age that it could have been left by the tyrannosaurid Qianzhousaurus (probably a synonym of Alioramus), whose fossil remains were previously found in the region.

Manic Moran wrote: »

So I was at the Witte museum yesterday with my juvenile paleontologist (it’s gone well beyond a “phase” now), and they had a picture of T Rex with feathers.

I’m sorry. I am fully aware that dinos were more feathered than we had believed for years, but a 5 ton chicken is just... wrong.

There is a lot of disinformation doing the rounds right now, especially online, regarding T. rex's life appearance. The most recent culprit is a documentary called The Real T. rex with Chris Packham, which somehow managed to convince a lot of people that we know a lot more about T. rex than we actually do, including that it could not roar and that it was covered on feathers (including orange "eyebrows").



The bare truth is that we have absolutely no evidence of T. rex being feathered. No trace of feathering has been found thus far with any T. rex specimen. Skin impressions of T. rex HAVE been found, and they show what appears to be a covering of small scales:



The problem is that these skin impressions are very small, and so people often argue that there may have been feathering in other parts of the animal's body; for example, the back and the neck.

Thing is we have skin impressions from several other tyrannosaurids, closely related to T. rex- such as Tarbosaurus, Albertosaurus, Gorgosaurus and Daspletosaurus- and these come from several parts of the body. Seeing as these animals are very closely related to T. rex, it seems logical to assume that if they were scaly all over, as suggested by the skin impressions, then T. rex probably was too.

Here's a composite of the skin samples known from several tyrannosaurids and where they come from in the animal's body:



So why do many people insist on T. rex being feathered? Thing is a few years ago, two theropods were discovered in China that had extensive impressions of feathering. These are Dilong and Yutyrannus. Dilong was a small animal, less than 2 m long, whereas Yutyrannus was pretty large, maybe up to 8 or 9 m long.



When the skeletons were analyzed it turned out they belonged to the group of the tyrannosauroids- a broad term for several families of presumably related theropods that include the Tyrannosauridae family (and T. rex with it). This of course led paleontologists to suggests that if these distant T. rex relatives were feathered, then T. rex probably was too. But this was before the skin samples from T. rex and other tyrannosaurids became well known.

In reality there's a 58 million year breach between these early tyrannosauroids and T. rex- that's comparable to the breach between humans and the earliest known primates. A lot can happen in 58 million years. Dilong and Yutyrannus are not classified as part of the Tyrannosauridae family, but tentatively considered as part of the Proceratosauridae. So they are not as close to T. rex as often implied by the supporters of the feathered T. rex hypothesis.

All in all, there's no evidence or reason thus far to assume that T. rex was feathered. There is a possibility that its ancestors were, and many paleontologists believe that the very youngest T. rex hatchlings possibly had some sort of fuzz to keep warm while small, but since no T. rex or hatchlings or nests of any sort have been found thus far, we can only wait for future discoveries.

Previously assigned to be an undetermined species of Daspletosaurus, CMN 11315, a tyrannosaurid specimen from Alberta, Canada, turns out to be just another Albertosaurus sarcophagus. under more detailed analysis. The specimen was problematic because it considerably inflated the longevity of genus Daspletosaurus.

Tyrannosauridae is rife with examples of species that have been coined on the basis of undiagnostic immature material, which has often led to overestimates of diversity (...)

To date, A. sarcophagus remains the only unequivocally identified tyrannosaurid species from the Horseshoe Canyon Formation

https://onlinelibrary.wiley.com/doi/full/10.1002/ar.24199

"Victoria", a newly announced, apparently privately-owned specimen, is the second most complete T. rex known, and likely died of a nasty infection following a bite on the jaw by another T. rex.

https://edition.cnn.com/2019/09/12/world/victoria-t-rex-fossil-scn/index.html

She was less than 30 years old when she died, lending credence to the idea that T. rex didn´t live much longer than that due to their violent intraspecific behavior.

Victoria was severely bitten on the jaw by another T. rex and the mouth infection that followed encompassed both jaws, likely killing her before she could reach adulthood. This type of infection often leads to sepsis, the researchers said.

David Hone, a senior lecturer and director of the biology program at Queen Mary University of London, is like the investigator of a Cretaceous crime scene.
He's been studying the bite marks to understand what happened, how they lived and who was feeding on who.
The nature of Victoria's injuries are unusual. Although there are many past examples of tyrannosaur fossils showcasing stages of injury and healing, the location of Victoria's are right on the front of the lower jaw.

Hone said he's never seen a major injury in this location before. But it's clear that the attack came from another T. rex. There's only one creature with big teeth that could rip up the face of a T. rex, and that's another one.

Mechanisms of soft tissue and protein preservation in Tyrannosaurus rex:

https://phys.org/news/2019-11-mechanisms-soft-tissue-protein-tyrannosaurus.html?fbclid=IwAR2juk3GP5Zl42qxtE5tuq6d9pF-_8UA-c_rpFHA2xVH1Ez2uC0ewaF4U1c

Jinbeisaurus, another smallish, early-ish tyrannosauroid, similar to the aforementioned Suskityrannus, but from China.

https://www.sciencedirect.com/science/article/pii/S0195667119301909

New tyrannosaur, Thanatotheristes, from late Cretaceous Canada. It appears to be most closely related to Daspletosaurus. The name means "death reaper".

https://www.sciencedirect.com/science/article/pii/S0195667119303611

A parasite similar to Trichomonas, which affects modern day birds, may have killed famous T. rex "Sue" and been frequent among tyrannosaurs and possibly other giant theropods. Article is in Czech.

https://dinosaurusblog.com/2020/04/02/tyranosauri-trichomonoza/

Spectacular "Dueling Dinos" fossil (which includes an as of yet unidentified tyrannosaurid and ceratopsid, possibly Tyrannosaurus and Triceratops, but still unconfirmed), may soon be sold to a Museum after US court rules that fossils belong to land owners.

The Montana Supreme Court this week ruled that fossils are not legally the same as minerals such as gold or copper. Therefore, Montana fossils, including a dramatic specimen of two dinosaurs buried together, belong to people who own the land where they are found, rather than to the owners of the minerals underneath that land.

The four-to-three decision upholds the way U.S. scientists have long approached questions of fossil ownership. It appears to defuse a potentially explosive 2018 ruling by the federal Ninth Circuit U.S. Court of Appeals that fossils went to the owners of mineral rights.

The fossil includes two apparently mostly complete dinosaurs, a smallish tyrannosaurid (initially claimed to be Nanotyrannus, and considered important in solving the Nanotyrannus vs juvenile Tyrannosaurus debate), as well as a ceratopsid. Despite the name, the dinos were likely not dueling at the moment of death, their closeness being instead an artifact of taphonomy.

A history of Tyrannosaurus rex museum displays, very interesting read.

https://extinctmonsters.net/2020/06/15/displaying-the-tyrant-king-redux/

Interesting article on whether you'd be able to escape a T. rex running (answer is both yes and no)

https://www.wired.com/story/how-outrun-dinosaur/

Famous T. rex specimen "Stan" to be auctioned. They hope it will be sold for around 8 million USD. Naturally, paleontologists are already divided over this, some complaining about such a great specimen going to private hands, others arguing that the specimen is not new and has been studied already for many years anyway.

https://edition.cnn.com/style/article/stan-t-rex-skeleton-auction-scli-intl-scn/index.html

https://www.news18.com/news/world/an-auction-house-with-good-bones-stan-the-t-rex-is-for-sale-2883109.html


Stan is considered to be the fifth most complete T. rex in the world, at around 70%. It is most notorious however for having the best preserved and most complete skull of any T. rex. It was likely a male (going by its narrow pelvis) and around 11.7 m long and 6-7 tons in life.