Is the T-Rex Actually Three Different Species in One?

A new study led by the dino consultant on ‘Jurassic Park’ may rule out previous explanations for skeletal differences.

Transcript

00:00 One of the most fearsome predators to walk the earth, Tyrannosaurus rex, needs no introduction.

00:10 But on closer examination of the bones, researchers now believe the iconic dino is actually three

00:16 different species.

00:18 The theory may explain variations across femur bones in specimens that have been found, which

00:23 scientists previously chalked up to sex or age differences.

00:27 A team of paleontologists led by Gregory Paul, the dinosaur specialist on Jurassic Park,

00:33 compared femur bones in 24 Tyrannosaurus skeletons found in North America.

00:38 Based on the degree of robustness, or relative strength of the bone, there seemed to be no

00:43 connection to specimen size, age or gender.

00:47 Furthermore, the distribution of robust and grassal bones across three geological layers

00:51 of sediment suggests that as time passed, Tyrannosaurus diverged into three distinct

00:57 species.

00:59 As Paul writes, "We propose that the changes in femur may have evolved over time, from

01:04 a common ancestor who displayed more robust femurs, to become more grassal in later species."

01:10 Based on the findings published in Evolutionary Biology, the team has nominated two new potential

01:15 species - T. imperator, otherwise known as Tyrant Lizard Emperor, and T. regina, Tyrant

01:22 Lizard Queen.

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