Exciting news has recently emerged from the Tiaojishan Formation of Liaoning, China, where a pterosaur fossil believed to be 160 million years old has been discovered. The fossil has been named Kunpengopterus antipollicatus – a name that translates to “opposite thumbs” in ancient Greek – but it has also earned the nickname “Monkeydactyl”.
Overview of Tiaojishan Formation
The Tiaojishan Formation is extensive with its geographical spread throughout western Liaoning Province and into the adjacent northern Hebei Province in China. This geological formation is primarily made up of intermediate lava and pyroclastic rocks, layered with basic volcanic rocks and sedimentary deposits. The area is known for its rich abundance of well-preserved fossil plants such as leaves, seeds, fruits, permineralized rhizomes, and wood.
Understanding the Pterosaur Species
The pterosaurs were reptiles – distant relatives of the dinosaurs – and stand out in history for being the first animals after insects to achieve powered flight. They evolved into numerous species, size range varied greatly with some large like an F-16 fighter jet, while others were as small as paper airplanes. Pterosaurs inhabited Earth during all periods of the Mesozoic Era, which spanned from 252.2 million to 66 million years ago.
Details About the Monkeydactyl Fossil (Kunpengopterus antipollicatus)
Interestingly, the “antipollicatus” suffix was added to the fossil’s name due to its opposed thumb feature – a discovery that could potentially be the first of its kind in a pterosaur. Indeed, it is far older than the pterosaur species identified in 2019 over in what is now Western Canada. That specimen, named Cryodrakon boreas, had an impressive wingspan of over 10 metres and was believed to have once flown over the heads of dinosaurs.
The Significance of Opposable Thumbs
The opposability of the thumb is characterised by the ability to flex, abduct and medially rotate the thumb in such a way that enables the thumb tip to touch the tips of other fingers. This kind of dexterity is seen, apart from humans, in some ancient monkeys and apes. However, humans have a longer and distally placed thumb as well as larger thumb muscles, giving them superior precision when it comes to grasping smaller objects. Hence why humans can perform intricate actions like holding a pen, unscrewing an earring stopper, or threading a needle.
Monkeydactyl’s Thumb Opposability
The research team carried out a thorough study of the K. antipollicatus fossil using micro-computed tomography (micro-CT), an imaging technique that utilises X-rays. By examining the fossil’s forelimb morphology and musculature, the researchers suggest that this particular pterosaur could have been well adapted to an arboreal lifestyle due to its hand’s grasping capabilities. The grasping hands of primates developed because of their tree-dwelling habits; having an opposable thumb greatly aided their ancestors in clinging onto branches. Therefore, it is reasonable to infer that K. antipollicatus too, with its opposable thumbs, lived a similar lifestyle.