Scientists find first ever southern tyrannosaur dinosaur

Mar 25, 2010
A 66-million-year-old Tyrannosaurus rex skeleton dubbed "Samson" is displayed at the Venetian Resort Hotel Casino in Las Vegas, Nevada in 2009. Tyrannosaurus rex, once believed to have only roamed the Earth north of the Equator, may also have lived in the southern hemisphere, paleontologists said Thursday.

(PhysOrg.com) -- Scientists from Cambridge, London and Melbourne have found the first ever evidence that tyrannosaur dinosaurs existed in the southern continents. They identified a hip bone found at Dinosaur Cove in Victoria, Australia as belonging to an ancestor of Tyrannosaurus rex.

The find sheds new light on the evolutionary history of this group of . It also raises the crucial question of why it was only in the north that tyrannosaurs evolved into the giant predators like T. rex.

The 30cm-long pubis bone from Dinosaur Cove looks like a rod with two expanded ends, one of which is flattened and connects to the hip and the other looks like a 'boot'.

According to Dr Roger Benson of the Department of Earth Sciences at the University of Cambridge, who identified the find: "The bone is unambiguously identifiable as a tyrannosaur because these dinosaurs have very distinctive hip bones."

The discovery lays to rest the belief held by some scientists that tyrannosaurs never made it to the southern continents.

"This is an exciting discovery because tyrannosaur fossils had only ever been found in the before and some scientists thought tyrannosaurs never made it down south.

"Although we only have one bone, it shows that 110 million years ago small tyrannosaurs like ours might have been found worldwide. This find has major significance for our knowledge of how this group of dinosaurs evolved." says Dr Benson.

Dr Paul Barrett, at the Natural History Museum, London and member of the research team commented: "The absence of tyrannosauroids from the southern continents was becoming more and more anomalous as representatives of other 'northern' dinosaur groups started to show up in the south. This find shows that tyrannosauroids were able to reach these areas early in their evolutionary history and also hints at the possibility that others remain to be discovered in Africa, South America and India."

The first relative of Tyrannosaurus rex from the southern continents has been discovered in Dinosaur Cove, Australia, shown on this map of the Earth 110 million years ago. © Dr Roger Benson, University of Cambridge

The bone would have come from an animal about three metres long and weighing around 80 kg, similar to a human, and would have had the large head and small arms that make tyrannosaurs so distinctive.

The newly identified dinosaur, known as NMV P186069, was much smaller than T. rex, which was 12 metres long and weighed around four tonnes. Giant size like this only evolved late in the tyrannosaur lineage.

Compared with T. rex, which lived about 70 million years ago at the end of Cretaceous period, NMV P186069 lived earlier during the Cretaceous, around 110 million years ago.

During the time of the dinosaurs the continents gradually went from a single supercontinent towards something like their present-day arrangement. This tyrannosaur is from the mid-stages of this continental break-up, when the southern continents of South America, Antarctica, Africa and Australia had separated from the northern continents, but had not separated from each other.

Part of the 110-million-year-old hip bone of an ancestor of T.rex uncovered in Australia © Dr Roger Benson, University of Cambridge

While answering the question of whether or not tyrannosaurs lived in both the southern and northern hemispheres, the new find leaves another, deeper mystery: why did tyrannosaurs evolve into giant predators such as T. rex only in the northern hemisphere?

According to Dr Benson: "It is difficult to explain why different groups succeeded in the north and the south if they originally existed in both places. What we need to know now is just how diverse the early radiation of tyrannosaurs was, why they went extinct, leaving only giant-sized, short-armed species like T. rex, and how successful they might have been in the southern hemisphere. We can only answer these questions with new discoveries."

The paper is published today in Science.

Explore further: Seeing dinosaur feathers in a new light

More information: Roger B. J. Benson et al, 'A Southern Tyrant Reptile' is published in Science on 25 March 2010.

Related Stories

Bizarre new horned tyrannosaur from Asia described

Oct 05, 2009

Now, just a few weeks after tiny, early Raptorex kriegsteini was unveiled, a new wrench has been thrown into the family tree of the tyrannosaurs. The new Alioramus altai—a horned, long-snouted, gracile cousi ...

Scientists discover 2 new dinosaur species

Apr 22, 2009

Researchers from Field Museum in Chicago have helped discover two new dinosaur species in China's Gobi Desert: a 5-foot-tall forebear of Tyrannosaurus rex and a half-ton beaked dinosaur reminiscent of a giant ostrich.

Scientists Discover New Species of Tyrannosaur

Feb 01, 2010

New Mexico is known for amazing local cuisine, Aztec ruins and the Los Alamos National Laboratory. In the January issue of the Journal of Vertebrate Paleontology, paleontologists Thomas Williamson of the Ne ...

'Tiny' new T-Rex ancestor found in China (w/ Video)

Sep 17, 2009

(PhysOrg.com) -- A 9-foot dinosaur from northeastern China had evolved all the hallmark anatomical features of Tyrannosaurus rex at least 125 million years ago. University of Chicago paleontologist Paul Sereno ...

T.rex's oldest ancestor identified

Nov 04, 2009

(PhysOrg.com) -- Remains of the oldest-known relative of T.rex have been identified, more than 100 years after being pulled out of a Gloucestershire reservoir, according to research published in the Zoological Jo ...

Recommended for you

New search planned for grave of Spanish poet Lorca

2 hours ago

Archeologists will start inspecting land in southern Spain near where the acclaimed poet Federico Garcia Lorca is believed to have been executed and buried at the start of the Spanish Civil War in 1936, officials said Friday.

Seeing dinosaur feathers in a new light

Oct 30, 2014

Why were dinosaurs covered in a cloak of feathers long before the early bird species Archaeopteryx first attempted flight? Researchers from the University of Bonn and the University of Göttingen attempt ...

Mexico archaeologists explore Teotihuacan tunnel (Update)

Oct 29, 2014

A yearslong exploration of a tunnel sealed almost 2,000 years ago at the ancient city of Teotihuacan yielded thousands of relics and the discovery of three chambers that could hold more important finds, Mexican ...

Peruvian dig reveals sacrificial mystery

Oct 29, 2014

Tulane University physical anthropologist John Verano has spent summers in Peru for the last 30 years, digging for ancient bones and solving their secrets. But his most recent work focuses on a unique archeological ...

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

out7x
not rated yet Mar 26, 2010
Australia was still attached to Antarctica near the south pole at this time.
JayK
1 / 5 (2) Mar 26, 2010
It was put there to challenge our belief system by Lucifer and his agents.

And I believe that T. Rex's short arms are indicative of the nature of its birth from the interbreeding of Nephilim and human women. It is plain as day, why can these scientists not see it?
James_Walker
not rated yet Apr 14, 2010
you religious idiot, go and post on a site that welcomes fools, religion is for the ignorant and lonely

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.