Discovery of Early, ‘Croc-Like’ Reptile Sheds New Light on Evolution of Dinosaurs

Article ID: 672690

Released: 10-Apr-2017 9:05 AM EDT

Source Newsroom: University of Birmingham

  • Credit: Natural History Museum, London, artwork by Mark Witton.

    Life reconstruction of the new species Teleocrater rhadinus, a close relative of dinosaurs, feasting on an ancient mammal relative, Cynognathus, in the Triassic of Tanzania. The large dicynodont Dolichuranus is seen in the background.

  • Credit: Dr Richard Butler, University of Birmingham

    Simplified depiction of phylogenetic relationships within Archosauria, including Teleocrater rhadinus.

A new species of ancient reptile has been described by scientists at the University of Birmingham, filling a critical gap in the fossil record of dinosaur cousins and suggesting that some features thought to characterise dinosaurs evolved much earlier than previously thought.

Described in a paper published today in Nature, the carnivorous reptile, Teleocrater rhadinus, was approximately 7- 10 feet in length, had a long neck and tail, and walked on four crocodile-like legs.

It roamed the Earth during the Triassic Period more than 245 million years ago – pre-dating the first true dinosaurs by around ten million years – and appears in the fossil record just after a large group of reptiles, known as archosaurs, split into a bird branch (leading to dinosaurs and eventually birds) and a crocodile branch (eventually leading to today’s alligators and crocodiles). Teleocrater and its kin are the earliest known members of the bird branch of the archosaurs.

The discovery overturns widely-held preconceptions by palaeontologists about the morphology of early dinosaur relatives, with many scientists anticipating that such creatures would be smaller, bipedal and more ‘dinosaur-like’.

Teleocrater fundamentally challenges our models of what the close relatives of dinosaurs would have looked like,’ says Dr Richard Butler from the University of Birmingham.

‘Dinosaurs were amazingly successful animals. It’s natural to want to know where they came from, and how they became so dominant. Teleocrater is hugely exciting because it blows holes in many of our classic ideas of dinosaur origins.’

All the specimens used to describe Teleocrater were collected from a rock unit called the Manda Beds, in the Ruhuhu Basin of southern Tanzania, Africa. Teleocrater fossils were first discovered in the region in 1933 by palaeontologist F. Rex Parrington, and subsequently studied by Alan J. Charig, former Curator of Fossil Reptiles, Amphibians and Birds at the Natural History Museum, in the 1950s.

However, due to a lack of crucial bones, such as the ankle bones, Charig could not determine whether Teleocrater was more closely related to crocodylians or to dinosaurs. Unfortunately, he died before he was able to complete his studies. 

Re-examination of Charig’s specimens by Butler and colleagues, combined with the discovery of additional fossils by a US-led team in Tanzania in 2015, has finally allowed the surprising relationship between Teleocrater and its dinosaur cousins to be revealed.

‘It’s astonishing to think that it’s taken more than 80 years for the true scientific importance of these fossils to be understood and published,’ says Dr Butler.

Professor Paul Barrett from the Natural History Museum, one of the other main authors of the work on Teleocrater, said:

‘My colleague Alan Charig would have been thrilled to see one of ‘his’ animals finally being named and occupying such an interesting position in the Tree of Life.

‘Our discovery shows the value of maintaining and re-assessing historical collections: many new discoveries, like this one, can be made by looking through museum collections with fresh eyes.’

ENDS

For more information, a copy of the paper, a video interview with Dr Richard Butler, more images or high-res versions of the attached images, contact the University of Birmingham Press Office on +44(0)121 454 5134 email pressoffice@contacts.bham.ac.uk or contact Liz Bell, Communications Manager for Science and Technology at the University of Birmingham, on +44(0)121 454 5134. 

Notes to editors:

The research involved a team of international scientists from institutions including the University of Birmingham, the Natural History Museum, Virginia Polytechnic Institute and State University, the Museo Argentino de Ciencias Naturales, The Field Museum, the University of Witwatersrand (South Africa), the University of Washington, Uppsala University (Sweden), the Russian Academy of Sciences, and Kazan Federal University (Russia).

Funding was received by the National Science Foundation, the National Geographic Society, a Marie Curie Career Integration Grant, a National Geographic Society Young Explorers grant, and the Russian Government Program of Competitive Growth of Kazan Federal University.

To avoid confusion, the authors of the paper are keen to stress the following:

  • Teleocrater is NOT a direct ancestor of dinosaurs.
  • Dinosaurs did NOT ‘evolve from’
  • Teleocrater is NOT an ancestor of crocodylians and/or birds.

About the University of Birmingham:

The University of Birmingham is ranked amongst the world’s top 100 institutions. Its work brings people from across the world to Birmingham, including researchers and teachers and more than 5,000 international students from nearly 150 countries. The University collaborates with partners across the world to produce ground-breaking research, deliver innovative teaching, and to create opportunities for students and staff to gain international experience.

About the Natural History Museum:

The Natural History Museum welcomes more than five million visitors a year and is a world-leading science research centre. The Museum was named the Cultural Attraction of the Year at the London Lifestyle Awards 2016, voted by the public. Through its unique collection and unrivalled expertise it is tackling the biggest challenges facing the world today. It helps enable food security, eradicate disease and manage resource scarcity. It is studying the diversity of life and the delicate balance of ecosystems to ensure the survival of our planet. For more information visit www.nhm.ac.uk.


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