The Tyrannosaur Thread- Anything T. rex or tyrannosaurid related

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.

First hatchling/embryo remains of a tyrannosaur identified! This is big news, as the fossil record of these creatures is rich in adult and large juvenile individuals, but we know next to nothing about their earliest growth stages.

"These are incredibly rare finds — the first of their kind in the world," lead researcher Gregory Funston, a paleontologist at the University of Edinburgh in Scotland, told Live Science in an email. "Juvenile tyrannosaurs of any kind are exceedingly rare, and we've never found any bones that we suspected might be embryos, until now."

The teensy, 1.1-inch-long (2.9 centimeters) tyrannosaur jawbone still sports eight little teeth. Because it was stuck in the surrounding rock, the researchers scanned the jawbone with a particle accelerator, which let them image the fossil without excavating it. Despite the jawbone's miniature size, "it looks surprisingly like other juvenile tyrannosaurid jaws," Funston said. "It has a deep groove on the inside and a distinct chin, which are both features that distinguish tyrannosaurs from other meat-eating dinosaurs."

These features helped convince other paleontologists that the jawbone truly is from a tyrannosaur — "we can know that these features can be used to identify tyrannosaurs no matter how immature they are,"

No eggs or egg shells associated with tyrannosaurs have ever been found, which has led to the suggestion that tyrannosaurs may have laid soft-shelled eggs, like those of turtles or snakes, instead of hard-shelled like those of birds. Other dinosaurs (such as Protoceratops and Mussaurus) are already known to have laid soft-shelled eggs.

The newborn tyrannosaur would've had a skull around 9 cm long (average skull length for house cats is around 9-10 cm).

Famous "Dueling Dinos" (which likely did not die dueling), until now in private hands, is now finally available for scientific study, and there's some tantalizing clues that the tyrannosaur may not in fact be Tyrannosaurus rex, despite coming from a fossil site (Hell's Creek Formation) where only T. rex had been confirmed among tyrannosaurids/giant theropods.

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According to paleontologists Peter Larson and Gregory Paul, the tyrannosaur found fossilized along with a ceratopsid has huge arms and fingers, proportionally, far beyond what one would expect from a juvenile tyrannosaurid. Paul goes as far as to suggest that it may actually be a dryptosaurid, a member of a different linneage that evolved in Appalachia (eastern North America) and known until now from only incomplete remains. We know dryptosaurids, unlike tyrannosaurids, had large and robust arms with large claws.

If confirmed, this would be proof that a) Tyrannosaurus rex was not the only large theropod in Hell Creek, and b) the Appalachian dryptosaurids managed to reach Laramidia (now western North America) and met their small armed tyrannosaurid cousins at the end of the Cretaceous before both went extinct.

If it does turn out to be a dryptosaurid, it will be the first good look at one since the discovery of Dryptosaurus' fragmentary remains in 1866...

Possible arm impression shows how a tyrannosaur got up from a prone position:

https://www.researchgate.net/publication/348002331_TRACKS_IN_THE_UPPER_CRETACEOUS_OF_THE_RATON_BASIN_POSSIBLY_SHOW_TYRANNOSAURID_RISING_FROM_A_PRONE_POSITION