Monkeydactyl: Prehistoric ‘Flying Monkey’ Suggests Tree-Climbing Abilities with Opposable Thumbs

The newly described Jurassic pterosaur may be the oldest animal known to possess opposable thumbs

Researchers have bestowed a newly described species of Jurassic flying reptile with the nickname Monkeydactyl because it has opposable thumbs, reports Maria Temming for Science News.

Paleontologists discovered the 160-million-year-old fossilized pterosaur in an ancient forest called Tiaojishan near modern Liaoning, China. The creature’s scientific name is Kunpengopterus antipollicatus and it may be the earliest animal known to possess what appears to be an opposable thumb.

The authors of the new research, published earlier this week in the journal Current Biology, suggest this opposable thumb, which could have given the pterosaur the ability to more effectively grasp objects in its environment, may have allowed K. antipollicatus to live in the trees.

To better understand the structure and function of the new pterosaur’s anatomy, the team scanned the fossil using micro-computerized tomography, an imaging technique that uses X-rays to create a 3-D image of an object by scanning it slice by slice. Analysis of Monkeydactyl’s forelimb morphology made researchers think it would have been well-suited for climbing, according to a statement.

Researchers also examined the question of whether K. antipollicatus was arboreal by studying its skeleton and 25 other pterosaur species alongside more than 150 other species known for tree climbing. The researchers say these comparisons also confirmed the Monkeydactyl moniker was appropriate, showing the animal could have had the right musculature and joint flexibility for climbing.

Moreover, several pterosaurs that lived around the same time and location as K. antipollicatus lacked opposable thumbs and don’t appear to have been tree climbers.

“Our results show that K. antipollicatus has occupied a different niche from Darwinopterus and Wukongopterus, which has likely minimized competition among these pterosaurs,” says Xuanyu Zhou, a paleontologist at the China University of Geosciences and the study’s lead author, in the statement.

But Kevin Padian, a paleontologist at the University of California, Berkeley who was not involved in the research, tells Isaac Schultz of Gizmodo that “an opposable thumb is not an infallible indication of arboreality.” For example, Padian tells Gizmodo that otters and raccoons have opposable thumbs but aren’t arboreal.

Padian also questions whether the position of K. antipollicatus’ proposed thumb in the fossil is indicative of the digit’s orientation in life.

“The bottom line, for me, is that the specimen’s articular surfaces are too poorly preserved to draw an inference of opposability,” he tells Gizmodo. “I think we would want more and better-preserved examples of this species before jumping to conclusions.”