A ‘creepy’ never-before-seen tyrannosaur could be the ‘missing link’ in T. rex evolution
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Paleontologists have discovered the remains of a never-before-seen tyrannosaurus that may have been a direct ancestor of the king dinosaur. Tyrannosaurus Rex. The new species could help settle a big debate about T. rexevolutionary lineage
The new species Daspletosaurus wilsoni, has a unique arrangement of spiked horns around the eyes. The tyrannosaurus was identified from parts of a fossilized skull and skeletal fragments, including a rib and a toe bone, dating to about 76.5 million years ago during the Cretaceous period (between 145 and 66 million years ago). Paleontologists at North Dakota’s Badlands Dinosaur Museum discovered the fossils in the Judith River Formation in northeastern Montana between 2017 and 2021, according to a new study, published Nov. 25 in the journal. Paleontology and evolutionary science (opens in a new tab).
The team initially stumbled upon the fossils after crew member Jack Wilson noticed a small piece of flat bone sticking out of the bottom of a cliff, which later turned out to be part of dinosaurthe nostril Excavating the bones, however, proved immensely difficult because they were buried under 26 feet (8 meters) of solid rock. The researchers had to painstakingly cut away large sections of the cliff with jackhammers before they could even begin to excavate individual bones.
The specimen, designated BDM 107, was nicknamed “Sisyphus” in recognition of the enormous effort required to remove the surrounding rock. (Sisyphus is a figure in Greek mythology who, after cheating death twice, was forced by Hades, the god of death, to repeatedly roll a rock up a mountain for eternity.)
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Researchers think so D. Wilson was the descendant of Daspletosaurus torosus and the predecessor of Daspletosaurus horneri, which probably arose between 77 and 75 million years ago. The recently discovered anatomy of the beast supports the idea that the Daspletosaurus the lineage is ancestral to the powerful T. rex. The three species of daspletosaurs belong to the family Tyrannosauridae, which includes nine genera, incl tyrannosaurus. (The genre Daspletosaurus is Greek for “scary lizard”).
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Until now, the Tyrannosauridae lineage has been difficult to unravel, making exact determination difficult evolutionary relationships between individual species.
“Many researchers disagree about whether tyrannosaurids represent a single lineage that evolved in place, or several closely related species that did not descend from each other,” wrote study co-authors and paleontologists Elías Warshaw and Denver Fowler in one statement (opens in a new tab). This has not been helped by a lack of high-quality specimens to examine, they added.
But the discovery of D. Wilson suggests that the three daspletosaurs came one after the other, like “consecutive ladder-like rungs in a single evolutionary lineage,” rather than branching off from each other as “evolutionary cousins,” the researchers wrote.
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D. Wilson is a good candidate to be a transitional species between D. bulls i D. baker because it shares a number of traits with older tyrannosaurs, such as having a prominent set of horns around the eye, as well as traits seen in younger species, such as expanded air sacs in the skull, the statement said .
“On this way, D. Wilson is a ‘middle ground’ or ‘missing link’ between older and younger tyrannosaur species,” the researchers wrote.
Since these species could have evolved one after the other, the team suggests that the rest of the tyrannosaurids, including T. rex, could also have arisen in a similar linear fashion. The researchers are currently planning a new study to explore this idea, according to the release.
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