Dinosaur King Ancestor, Missing Link in T. Rex Evolution has Spiked Horns Around Eyes

The dinosaur king's ancestor, which had spiked horns surrounding its eyes and maybe the final step in the evolution of the T. Rex, was discovered by a team of paleontologists.

A previously unknown tyrannosaur that may have been a direct ancestor of Tyrannosaurus rex has been discovered by paleontologists. The newly discovered species may help resolve a contentious issue regarding the T. rex's evolutionary history.

Daspletosaurus Wilsoni: Sisyphus

The eyes of the recently discovered species Daspletosaurus wilsoni are surrounded by a peculiar arrangement of spiked hornlets. Parts of a fossilized skull and other skeletal remains, such as a rib and toe bone, from the Cretaceous period, which lasted from 145 million to 66 million years ago, were used to identify the tyrannosaur.

According to a new study, which was just published in the journal Paleontology and Evolutionary Science, the fossils were discovered at the Judith River Formation in northeastern Montana between 2017 and 2021 by North Dakota's Badlands Dinosaur Museum paleontologists.

Jack Wilson, a crew member, spotted a small, flat piece of bone sticking out from the base of a cliff; it later turned out to be a piece of the dinosaur's nostril, which is how the team first came across the fossils. The bones, however, were buried under 26 feet of solid rock, which made excavation of them extremely difficult. Before they could even begin to begin excavating the individual bones, the researchers had to meticulously chisel away substantial portions of the cliff with jackhammers.

The specimen, BDM 107, was mockingly dubbed "Sisyphus" in honor of the tremendous amount of work needed to remove the surrounding rock. Greek mythology's Sisyphus is a character who, after twice eluding death, was made to roll a boulder up a mountain repeatedly for all of time by Hades, the god of death.

Read also: Drying River Reveals Dinosaur Footprints from 113 Million Years Ago 

T. Rex Lineage

Daspletosaurus horneri, which most likely appeared between 77 and 75 million years ago, is thought to have descended from Daspletosaurus torosus, and D. wilsoni was its predecessor. The newfound creature's anatomy lends credence to the theory that the mighty T. rex descended from the Daspletosaurus genus.

The discovery of D. wilsoni, however, points to the possibility that the three daspletosaurs evolved sequentially rather than branching off from one another such as "evolutionary cousins," as previously thought.

According to the statement, D. wilsoni is a viable candidate as a transitional species between D. horneri and D. torosus because it exhibits characteristics of both more recent and older tyrannosaurs, such as expanded air-pockets in the skull and a prominent set of horns around the eye.

The researchers wrote that D. wilsoni serves as a "middle ground" or "missing link" between the younger and older tyrannosaur species in this way, Live Science reports.

The team hypothesizes that since these species could have developed one after the other, the remaining tyrannosaurids, including T. rex, could have also emerged in a similar linear pattern. According to the statement published by the Dickinson Museum Center, the researchers are currently preparing a new study to investigate this notion.

Related article: Largest Dinosaur Species: T. Rex Might have been Bigger, Heavier than Previously Thought