Long-forgotten fossils of a crocodile-like creature with 'crankles' could be the missing link in dinosaur evolution
- Teleocrater rhadinus lived around 245 million years ago in Tanzania
- Its fossils lay unexamined at the Natural History Museum for 60 years
- It is the link between dinosaurs and the ancestor they share with crocodiles
- It's the oldest member of bird-line of dinosaurs and fills a gap in fossil records
By
Victoria Allen Science Correspondent For The Daily Mail and
Phoebe Weston For Mailonline
Published: 18:00 BST, 12 April 2017 | Updated: 08:30 BST, 13 April 2017
http://www.dailymail.co.uk/sciencet...uses-rethink-dinosaur-evolution.html#comments
Fossils which lay unexamined at the Natural History Museum for 60 years may provide the ‘missing link’ in the evolution of dinosaurs.
Bones from the Teleocrater rhadinus, one of the earliest dinosaur relatives, were discovered in the 1950s.
But experts at the Natural History Museum in
London had no way of knowing its link to the dinosaurs because vital parts including the ankles were missing.
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Teleocrater rhadinus (pictured), from the Middle Triassic epoch of Tanzania was a lightly built, four-legged carnivore. It looked more like a crocodile than the small animals who used two legs to walk, which we often associate with dinosaurs at this point in evolution
THE TELOCRATER
Experts believe the Telocrater was two to three metres long (six feet to ten feet), with a long tail and was around about 0.5–0.75 metres (1.6 to 2.4 feet) tall at the hip.
Teleocrater is more closely related to dinosaurs and birds than to crocodiles, belonging to the ‘bird-line’ of archosaur evolution.
It predates the first true dinosaurs by around ten million years.
They are from the Middle Triassic epoch of Tanzania around 245 million years ago.
The fossils were excavated from the Manda Beds of southern Tanzania.
Teleocrater likely stood on all four legs with its limbs positioned directly underneath its body.
It had a relatively long neck like other dinosaur relatives and sharp, serrated teeth, suggesting it was a carnivore.
The Triassic Period lasted from 252–201 million years ago, and the following animals arose during this time: dinosaurs, crocodile relatives, mammals, pterosaurs, turtles, frogs, and lizards.
It took a new fossil discovery in Tanzania two years ago to fill in the missing piece of the fossil record.
Now, after decades of discussion in which scientists assumed early dinosaur relatives looked like chicken-sized mini-dinosaurs on two legs, they finally have the truth.
In fact, the Teleocrater rhadinus was much more fearsome, at seven to 10 feet long, with a long neck and tail. It walked on four legs rather like modern lizards.
It had features present in the last common ancestor of birds and crocodylians with classic dinosaur characteristics.
'There is a depression of the top of the head that is in Teleocrater and in dinosaurs', Dr Sterling Nesbitt from Virginia Tech Institute told MailOnline.
'Also, Teleocrater has a muscle scar (where muscles attach to bones) on the upper thigh bone - a feature found in dinosaurs and their close relatives', he said.
Members of this new lineage also had a crocodylian-like ankle joint, or 'crankles', with some classic dinosaur characters, such as depressions for enlarged dinosaur-like jaw.
'Teleocrater is represented by at least four partial individual skeletons from nearly the same location in southern Tanzania', said Dr Nesbitt.
Scientists can trace the Teleocrater, which lived more than 245 million years ago, back to the time just after a large group of reptiles known as the archosaurs split into a bird branch, which would also become the dinosaurs, and a crocodile branch, also creating modern alligators.
The research, led by Birmingham University and Virginia Tech, is published in the journal Nature.
Dr Richard Butler, from the University of Birmingham, said: ‘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.
Co-author Professor Paul Barrett, from the Natural History Museum, added: ‘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.’
The fossils examined include samples collected from rocks in the Manda beds of southern Tanzania in 1933 and studied by palaeontologist Alan Charig, a former curator of fossil reptiles, amphibians and birds at the Natural History Museum, in the 1950s.
The study, led by Virginia Tech Institute, discovered a new species of dinosaur, Teleocrater rhadinus, (pictured) predates the first true dinosaurs by around ten million years
But he died before he could make a breakthrough, lacking the complete bones he needed.
After additional fossils were found in Tanzania in 2015, the complete record was re-examined, casting new light on the Teloecrater.
The creature lived in the Triassic period, 10 million years before the dinosaurs dominated the earth.
Teleocrater is assigned to an entirely new group of reptiles, called Aphanosauria, which is one of the last archosaurs before they split and become pterosaurs (flying reptiles) and dinosaurs
Ken Angielczyk, associate curator of fossil mammals at the Field Museum of Natural History in Chicago, who is also a study author, said: ‘Teleocrater has unexpectedly crocodile-like features that are causing us to completely reassess what we thought about the earliest stages of dinosaur evolution.
‘Surprisingly, early dinosaur relatives were pretty profoundly not dinosaur-like.
‘Scientists generally don't love the term “missing link”, but that's kind of what Teleocrater is - a missing link between dinosaurs and the common ancestor they share with crocodiles.’
TELOCRATER FOSSILS
The first fossils of Telocrater were collected in 1933 by F. Rex Parrington - a famous palaeontologist based at the University of Cambridge.
Other remains of Teleocrater were collected by an international team including many of the authors of this paper in 2015.
All specimens of Teleocrater are from a rock unit called the Manda Beds, in the Ruhuhu Basin of southern Tanzania, Africa.
Teleocrater was found with other reptiles and early relatives of mammals in the Manda Beds, which represent Triassic-aged river deposits.
The carnivorous creature is the earliest member of the bird branch discovered, but has ankles more like crocodiles than dinosaurs and birds, meaning it would have had a lower, more reptilian gait.
Its name means ‘slender complete basin’, in reference to its lean build and closed hip socket.
Professor Barrett added: ‘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.’
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All specimens of Teleocrater are from a rock unit called the Manda Beds, in the Ruhuhu Basin of southern Tanzania, Africa
Read more:
Missing link in dinosaur evolution is found in Tanzania | Daily Mail Online
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