Context: The new pterosaur fossil was discovered in the Tiaojishan Formation of Liaoning, China, and is believed to be 160 million years old.

• It has now been described by an international team of researchers from China, Brazil, UK, Denmark and Japan, and has been named Kunpengopterus antipollicatus, also dubbed “Monkeydactyl”.
• Researchers have described a pterosaur species with opposable thumbs, which could likely be the earliest-known instance of the limb.

• The pterosaur species were reptiles, close cousins of dinosaurs and the first animals after insects to evolve powered flight.
• They evolved into various species; while some were as large as an F-16 fighter jet, others were as small as paper airplanes.

Why is opposability of the thumb important and how did it evolve?

• Anthropogeny defines opposability of the thumb as being able to “simultaneously flex, abduct and medially rotate the thumb” in a way that one is able to bring the tip of the thumb to touch the tips of the other fingers.
• Along with humans, some ancient monkeys and apes also had opposable thumbs.
• Humans, however, have a relatively longer and distally placed thumb, and larger thumb muscles.
• This means that humans’ tip-to-tip precision grip when holding smaller objects is superior to non-human primates.
• This is the reason that humans are able to hold a pen, unscrew an earring stopper, or put a thread through a needle hole.
• The grasping hands of primates developed as a result of their life in the trees — an opposable thumb made it easier for the common ancestor of all primates to cling on to tree branches.

https://indianexpress.com/article/explained/explained-what-is-monkeydactyl-the-flying-reptile-with-the-oldest-opposable-thumbs-7272513/

Download PDF