New dinosaur species may be closest known relative of T. rex, study suggests

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A brand new dinosaur species may be the closest known relative of Tyrannosaurus rex, a brand new study suggests.

The analysis reshapes scientists’ understanding of how essentially the most well-known dinosaur – T. rex – may need first arrived in North America, by introducing its earliest known relative on the continent.

Researchers have recognized the newly found subspecies of tyrannosaur known as Tyrannosaurus mcraeensis.

The predator is older and extra primitive than its better-known cousin, however simply as massive – roughly the scale of a double-decker bus.

The findings are primarily based on a partial cranium collected years in the past from western New Mexico and on show on the New Mexico Museum of Natural History and Science (NMMNHS).

It exhibits that tyrannosaurus was in North America tens of millions of years earlier than palaeontologists beforehand thought.

Based on the placement of different fossil finds which have beforehand been dated to between 66 and 75 million years in the past, the researchers recommend T. mcraeensis may have lived between 71 and 73 million years in the past – some 5 to seven million years earlier than T. rex.

T. rex is so well-known, so it grew to become attainable to point out the New Mexico tyrannosaur was one thing new.

Dr Nick Longrich, a co-author from the Milner Centre for Evolution on the University of Bath, mentioned: “The differences are subtle, but that’s typically the case in closely related species.

“Evolution slowly causes mutations to build up over millions of years, causing species to look subtly different over time.”

When then-student Sebastian Dalman started a restudy of a horned dinosaur, it compelled a broader rethink of the dinosaurs from western New Mexico.

“I started working on this project in 2013 with co-author Steve Jasinski and soon we started to suspect we were onto something new,” he mentioned.

A staff of scientists from New Mexico, elsewhere within the USA, Canada, and Bath, within the UK, was assembled to study the animal, going by the skeleton bone by bone.

They all discovered refined variations within the form of, and joins between, the cranium bones of the specimen and the handfuls of T. rex skeletons beforehand discovered.

The newly found dinosaur was roughly the identical measurement as a T. rex, which measured as much as 40 toes (12 metres) lengthy and 12 toes (3.6 metres) excessive, and it additionally ate meat.

While the brand new discovery predates T. rex, refined variations within the jaw bones make it unlikely it was a direct ancestor, the researchers mentioned.

Experts recommend this raises the likelihood there are nonetheless extra new tyrannosaur discoveries to be made.

Dr Spencer Lucas, paleontology curator at NMMNHS, mentioned: “Once again, the extent and scientific importance of New Mexico’s dinosaur fossils becomes clear – many new dinosaurs remain to be discovered in the state, both in the rocks and in museum drawers.”

According to the researchers, the brand new discovery expands our understanding of tyrannosaurs.

First, they recommend the apex predators lived in what’s now the southern United States at the very least 72 million years in the past, lengthy earlier than the primary fossils of T. rex have been present in the identical area.

The new fossils additionally recommend bigger, extra closely constructed, and extra superior species advanced within the southern United States, in comparison with the smaller and extra primitive tyrannosaurs that inhabited Montana and Canada.

The findings are printed within the Scientific Reports journal.