It rose above the sky, had opposite thumbs and lived in China during the Jurassic era: meet the “Monkeydactyl” – a newly discovered ancient dinosaur.
The bizarre Kunpengopterus antipollicatus, nicknamed Monkeydactyl, lived in a forest ecosystem 160 million years ago, an international team of researchers said in a report published Monday in the journal Current Biology. Antipollicatus means “opposite thumb” in ancient Greek.
Pterosaurs were the first known vertebrates to fly, researchers said. The arboreal pterosaur species is the oldest of its kind with true opposite thumbs, a phenomenon never seen before in the species.
The discovery is also the earliest known record of a true opposite thumb in the history of the earth.
Scientists found the Monkeydactyl fossil in the Tiaojishan Formation of Liaoning, China, in September 2019. Using micro-CT scans to enlarge the anatomical features, they found that the small fossil record was of both hands, with an opposite ‘pollex’ or thumb on each.
Chuang Zhao
“The fingers of ‘Monkeydactyl’ are small and partially embedded in the plate. Thanks to micro-CT scanning we were able to see through the rocks, create digital models and tell how the opposite thumb articulates with the other finger bones,” said co-author . Fion Waisum Ma said in a statement. “It’s an interesting discovery. It provides the earliest evidence of a true opposite thumb, and it comes from a pterosaur – which was not known to have an opposite thumb.”
An opposite thumb is very rare in reptiles – it usually occurs in humans and other mammals.
Researchers say the Monkeydactly, a type of darwinopteran named after Charles Darwin, used the thumb for climbing and grabbing, an adaptation to live in trees. In addition to the thumbs, researchers determined that the animal is very small, with a wingspan of about 33 centimeters.
It manages to avoid most competition in its complex forest habitat, which contains closely related species adapted to different niches.
“Darwinopterans is a group of pterosaurs from the Jurassic of China and Europe, named after Darwin because of their unique transition anatomy that revealed how evolution affected the anatomy of pterosaurs over time,” said co-author Rodrigo V Pegas said. “In addition, a specific darwinoptera fossil with two associated eggs has been preserved, which reveals clues for the reproduction of pterosaurs. For these reasons, they have always been considered precious fossils and it is impressive that new species of darwinoptera will still surprise us!”