#Tyrannosaurus mcraeensis

[etchif]

paleo doodles from today :^) Kunpengopterus, Spinosaurus, pretty generic tyrannosaurid I arbitrarily decided is an adolescent T. mcraeensis, Carnotaurus and Buitreraptor

[cretaceous-kid]

well, it seems a new Tyrannosaurus species was described today! the paper, (authored by Sebastian G. Dalman, Mark A. Loewen, and Nicholas R. Longrich) is based on remains from ancient Laramidia (now New Mexico) previously attributed to T. rex. These particular fossils are dated 6-7ish million years before T. rex. This newly proposed species, Tyrannosaurus mcraeensis, will hopefully give some insight into the evolution of T. rex, which has largely been shrouded in mystery.

The working theory has been migration from what is now Asia, *but* if T. mcraeensis continues to hold up to scrutiny it would turn out that the reverse is true! or even that a double back migration saw large tyrannosaurine dinosaurs migrate to Asia, only to migrate once again towards the northern part of North America!

Obviously the paper goes into far more detail, so i’ve included it below. give it a look!

(art at the top of the post was made by Sergey Krasovskiy)

[cypressure]

the Hall Lake tyrant

[dani-m-art]

Heard there's a new tyrannosaur on the block

(semi-sketchy graphite drawing of Tyrannosaurus mcraeensis)

[new-dinosaurs]

Tyrannosaurus mcraeensis Dalman et al., 2024 (new species)

(Lower jaw bones of Tyrannosaurus mcraeensis [scale bar = 20 cm], from Dalman et al., 2024)

Meaning of name: mcraeensis = from the McRae Group

Age: Late Cretaceous (Campanian or Maastrichtian)

Where found: Hall Lake Formation, New Mexico, U.S.A.

How much is known: Partial skull and parts of the tail vertebrae of one individual.

Notes: In recent years, the genus Tyrannosaurus has generally been considered to consist of only one well-established species, T. rex. However, a new study argues that the type specimen of T. mcraeensis should be considered a new species based on various differences in the shape of its skull bones, as well as the fact that it may have been up to 7 million years older than T. rex. T. mcraeensis was about the same size as T. rex, so if this is accurate, it may suggest that the ancestors of Tyrannosaurus evolved their giant body size in the southern parts of North America. That being said, not all tyrannosaurid researchers are convinced of the distinctiveness and age of T. mcraeensis.

Reference: Dalman, S.G., M.A. Loewen, R.A. Pyron, S.E. Jasinski, D.E. Malinzak, S.G. Lucas, A.R. Fiorillo, P.J. Currie, and N.R. Longrich. 2024. A giant tyrannosaur from the Campanian–Maastrichtian of southern North America and the evolution of tyrannosaurid gigantism. Scientific Reports 13: 22124. doi: 10.1038/s41598-023-47011-0

[makairodonx]

A special Hallow’s Eve-themed present for those of you who happen to be big dinosaur fans!!

[johann1220]

Southern Tyrant

(All assets are done in Blender & made by me.)

[aberrantologist]

A butterfly finds a comfortable spot to land. Starring the recently described Tyrannosaurus mcraensis.

[hhhhhhhhhhh934]

Tyrannosaurus mcraeensis, made using a skeletal from the official paper

[joakinmar]

Tyrannosaurus mcraeensis by Emily Stepp.

[veloci-raptor]

The First Flocking of 2024

Guanlingsaurus/Tyrannosaurus mcraeensis

Orodromeus/Fruitadens

[mindblowingscience]

A new species of tyrannosaur from southern North America that may the closest known relative of Tyrannosaurus rex is described in a study published in Scientific Reports. Sebastian Dalman and colleagues identified the new species—which they have named Tyrannosaurus mcraeensis—by examining a fossilized partial skull, which was previously discovered in the Hall Lake Formation, New Mexico, U.S.

Continue Reading.

[greenfrog04]

A giant tyrannosaur from the Campanian–Maastrichtian of southern North America and the evolution of tyrannosaurid gigantism

Published 11th January 2024

Discovery of a new tyrannosaurin, Tyrannosaurus mcraeensis, based on a fossil from the Hall Lake Formation of New Mexico previously referred to as Tyrannosaurus rex. Tyrannosaurus mcraeensis predates Tyrannosaurus rex by ~ 6–7 million years, yet they were similar sizes, Phylogenetic analysis leads to Tyrannosaurus mcraeensis as sister to Tyrannosaurus rex and indicates that Tyrannosaurini originated within southern Laramidia.

Locality and stratigraphy of Tyrannosaurus mcraeensis, reconstruction of cranial elements and silhouette; Cranial elements of Tyrannosaurus mcraeensis holotype

Mandibular elements of Tyrannosaurus mcraeensis holotype

phylogenetic anaylsis of Tyrannosaurus mcraeensis

Source:

(I'm back from a break, enjoy reading this great publication! It took a few years to make so support the team who worked on this and click on the link if you're interested.)

[ildarotyrannus]

A relatively quick portrait of Tyrannosaurus mcraeensis from the Campanian-early Maastrichtian of the Hall Lake Formation in New Mexico. The dinosaur is described by partial jaw and skull fragments, as well as isolated teeth and chevrons. Initially, some of these bones were described as belonging to T. rex. T. mcraeensis, according to the team of paleontologists who described it, is characterized by a number of subtle differences from the type species in individual bones, including the shape of the postorbital protuberance, as well as teeth with thick tips, like those of the Asian Tarbosaurus. This dinosaur reached the same large size as the later T. rex. Its specific name refers to a sequence of rock layers called the "MacRae group" from which the bones were extracted. The animal belongs to a faunal complex that includes the large chasmosaurine Sierraceratops, the large hadrosaur and the titanosaur (probably Alamosaurus). The description of T. mcraeensis shows that North American tyrannosaurs became giants in the south of Laramidia, and then spread northward. It is worth noting that some paleontologists have been critical of the new taxon. For example, Thomas Carr points out that the differences are too small and one specimen is clearly not enough to distinguish the species. Anyway, I decided that the dinosaur deserves an image. Adobe Photoshop, 2024.

[tyrannoninja]

Tyrannosaurus versus Sierraceratops

In the semitropical forests of Late Cretaceous North America around 70 million years ago, Tyrannosaurus mcraeensis battles the ceratopsian Sierraceratops turneri. T. mcraeensis is a proposed species within the Tyrannosaurus genus based on a specimen from New Mexico’s Hall Lake Formation that may date between 72 and 70 million years ago. Its species name may not be as evocative or catchy as that of T. rex, but the two species seem to have been of similar size and power, so T. mcraeensis deserves some respect too (if it is a valid species after all).

[fishsfailureson]

Drew a little bust of the new Tyrannosaurus species