The Tyrannosaur Thread- Anything T. rex or tyrannosaurid related

Found this article that is obviously pro-Prokopi.

http://www.tampabay.com/news/humaninterest/paleontologist-may-lose-freedom-for-living-his-dream/1268296

Thanks Squeaky


I've merged your thread and another about the same case into this one.

I thought the ten years were for fossil smuggling, which did seem excessive...

Lythronax, new "king of gore" tyrannosaur

Expect many excessively bloody illustrations of this critter during the following months. It was not very big, but had a short wide snout and big teeth much like Tyrannosaurus rex despite being the oldest tyrannosaurid known.

http://www.theguardian.com/science/2013/nov/06/lythronax-argestes-tyrannosaurs

At last, a tyrannosaur trackway- may be from Albertosaurus, Gorgosaurus or Daspletosaurus- shows these theropods did travel (hunt?) in small groups at least part of the time. In this case, three tyrannosaurs aged 20 to 30 were walking side by side, although keeping a respectful distance from each other.

http://www.plosone.org/article/info%3Adoi/10.1371/journal.pone.0103613

http://www.theguardian.com/science/2014/jul/23/tyrannosaurs-hunted-packs-tracks-canada

Still no evidence of pack hunting with adults and juveniles working together, tho

Nothing unexpected but very interesting all the same. Daspletosaurus joins Tyrannosaurus and Gorgosaurus/Albertosaurus as a known tyrannosaur cannibal.

http://www.independent.co.uk/news/science/giant-cannibalistic-dinosaurs-engaged-in-ritualistic-fighting-10166911.html

This very interesting paper suggests albertosaurines such as Albertosaurus and Gorgosaurus (which may conceivably be one single genus) had a system akin to a lateral line that allowed them to better detect wind direction and align according to it during the hunt. 

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0187064

TIL Albertosaurus was named the same year Alberta became a province.

https://royaltyrrellmuseum.wordpress.com/2018/08/12/the-discovery-of-canadas-first-known-meat-eating-dinosaur/

Today we have many more remains and know far more about Albertosaurus. It could grow up to 9, maybe 10 meters long, had a bite force comparable to that of a great white shark, and was the dominant predator in North America from 71 to 68 million years ago. It apparently went extinct at about the same time as Tyrannosaurus rex appeared in North America.

Small tyrannosauroid named after Greek god of impending doom

This is an interesting find, as it shows what tyrannosauroids looked like and what niche they occupied 96 million years ago, a time in which North America was still ruled by allosaur-type creatures.

The new tyrannosauroid is called Moros intrepidus, was about 3.5 m long and would've been a fast running predator of small animals, thus avoiding competition with the likes of the contemporary Siats (the dominant predator at the time as far as we know).

https://www.nationalgeographic.com/science/2019/02/new-tiny-t-rex-relative-moros-fills-north-american-fossil-gap/

A new study suggests the Canadian T. rex known as "RSM P2523.8" (a.k.a. "Scotty") exceeds even the famous Sue/FMNH PR2081 (until now considered the largest T. rex specimen known from decent remains) in weight, estimated at almost 9 tons.

The body mass of RSM P2523.8 is
thus estimated to be ~8,870 kgs (+/- 25%).

It would thus be the heaviest T. rex on record, but not necessarily the longest or tallest:

notably
exceeds all T. rex specimens that have been previously categorized as robust (Larson, 2008b).
However, in many length measurements (proximodistal femoral, tibial and jaw length) RSM
P2523.8 is exceeded by some individuals previously categorized as gracile (Larson, 2008b).
Whether or not a robust/gracile dichotomy exists among T. rex, these comparisons indicate that
RSM P2523.8 was a large and robustly-proportioned individual, but likely with a shorter total
hip-height and snout-vent length than other known specimens showing more elongate
proportions

https://onlinelibrary.wiley.com/doi/...6lrXXD1-pKQdk&

This would make "RSM P2523.8/ "Scotty" heavier than any other giant theropod for which there's reliable estimates, although the study does accept that there's a much more fragmentary record for the likes of Giganotosaurus, Tyrannotitan and Spinosaurus, and new finds may show these grew just as large if not larger.

Although RSM P2523.8 has an estimated weight more than 40% greater than the next
largest known theropod taxon, specimens of several other theropod species (including
Giganotosaurus carolinii and Tyrannotitan chubutensis) have femoral proportions indicative of
body masses greater than those of most other adult T. rex specimens. As
such, it is likely that further sampling of these other giant theropods, all of which are represented
by fewer specimens than T. rex, may yield larger individuals that match or surpass the size of
RSM P2523.8. In the case of Giganotosaurus carolinii, a sing dentary is known that does hint at
a greater maximum size (Calvo, 2000).

Possible tyrannosauroid tooth found in Japan

https://www.sankei.com/life/photos/190419/lif1904190032-p3.html

Small, potential ancestor to T. rex found in New Mexico, named Suskityrannus or "coyote-like tyrant".

https://www.pbs.org/wgbh/nova/article/suskityrannus-hazelae/



At only one meter tall at the hips it was only a fraction of T. rex's size but is very similar, proportion-size, to juvenile T. rex.

Here's the fragments of Suskityrannus' skeleton compared to T. rex's jaw:

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.