LONDON, Apr 28: The notorious carnivore Tyrannosaurus rex had a ‘bizarre’ vegetarian cousin with a tiny head, long neck and blunt fingers, according to scientists, who say the creature is proving to be an evolutionary jigsaw puzzle.
Chilesaurus diegosuarezi discovered in Chile is being referred as a ‘platypus’ dinosaur because of its bizarre combination of characters that resemble different dinosaur groups.
Chilesaurus boasted a proportionally small skull, hands with two fingers like Tyrannosaurus rex and feet more akin to primitive long-neck dinosaurs.
Chilesaurus diegosuarezi is nested within the theropod group of dinosaurs, the dinosaurian group that gathers the famous meat eaters Velociraptor, Carnotaurus and Tyrannosaurus, and from which birds today evolved.
The presence of herbivorous theropods was up until now only known in close relatives of birds, but Chilesaurus shows that a meat-free diet was acquired much earlier than thought.
Chilesaurus diegosuarezi is named after the country where it was collected, as well as honouring Diego Suarez, the seven year old boy who discovered the bones.
He found the fossil remains of this creature at the Toqui Formation in Aysen, south of Chilean Patagonia, in rocks deposited at the end of the Jurassic Period, approximately 145 million years ago.
Due to Chilesaurus’ unusual combination of characters, it was initially thought that Diego had uncovered several species.
However, since Diego’s find, more than a dozen Chilesaurus specimens have been excavated, including four complete skeletons – a first for the Jurassic Period in Chile – and they demonstrate that this dinosaur certainly combined a variety of unique anatomical traits.
Most of the specimens are the size of a turkey, but some isolated bones reveal that the maximum size of Chilesaurus was around three metres long.
Chilean and Argentinian palaeontologists from institutions including the University of Birmingham, along with Diego’s parents, have been studying these skeletons.
Other features present in very different groups of dinosaurs Chilesaurus adopted were robust forelimbs similar to Jurassic theropods such as Allosaurus, although its hands were provided with two blunt fingers, unlike the sharp claws of fellow theropod Velociraptor.
Chilesaurus represents one of the most extreme cases of mosaic convergent evolution recorded in the history of life.
For example, the teeth of Chilesaurus are very similar to those of primitive long-neck dinosaurs because they were selected over millions of years as a result of a similar diet between these two lineages of dinosaurs.
The finding was published in the journal Nature. (PTI)
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