First animal with opposable thumbs

First animal with opposable thumbs
Kunpengopterus antipollicatus ('Monkeydactyl')
April 2021

The earliest-known animal to have opposable thumbs was a prehistoric flying reptile or pterosaur officially known as Kunpengopterus antipollicatus, but nicknamed "Monkeydactyl" due to its monkey-like hand structure. This remarkable species was formally described in the journal Current Biology in April 2021, and existed in north-eastern China approximately 160 million years ago during the Jurassic Period. Its thumbs were truly opposable, because the creature's rock-embedded fossil skeleton reveals that it could touch the inside of its thumbs to the insides of its other fingers, just like humans and to a lesser extent apes and most Old World monkeys can do. Monkeydactyl is the first pterosaur known to have been able to do this, and researchers think that it may have used this ability for arborealism (climbing trees), possibly seeking insects and other tree-dwelling prey to eat, its opposable thumbs enabling it to grasp tightly onto branches.

Monkeydactyl's only known fossil remains were unearthed in China in April 2019, and consist of a rock-embedded skeleton. Consequently, in order not to destroy or damage this scientifically significant specimen by attempting to extract it from the rock, its researchers chose instead to leave it embedded, and construct a three-dimensional image of it for study purposes, using micro-CT scanning.

As noted by one of its lead researchers, Brazilian palaeontologist Dr Rodrigo V Pêgas: "With this detail, we’re able to look at the fossil from any angle, and make sure that the bones are in their right [original] place".