From UPSC perspective, the following things are important :
Prelims level : Monkeydactyl
Mains level : Evolution of natural history
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 aeroplanes.
- The new pterosaur fossil was discovered in the Tiaojishan Formation of Liaoning, China, and is thought to be 160 million years old.
- It has now been described by an international team of researchers from China, Brazil, the UK, Denmark and Japan, and has been named Kunpengopterus antipollicatus, also dubbed “Monkeydactyl”.
What has the team found?
- “Antipollicatus” in ancient Greek means “opposite thumbs”, and it was attached to the name because the researchers’ findings could be the first discovery of a pterosaur with an opposed thumb.
- Researchers suggested that K. antipollicatus could have used its hand for grasping, which is likely an adaptation for arboreal life.
What makes it special?
- Opposability of the thumb enables the species 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 long 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.
Try this PYQ:
Q.Some species of plants are insectivorous. Why?
(a) Their growth in shady and dark places does not allow them to undertake sufficient photosynthesis and thus they depend on insects for nutrition
(b) They are adapted to grow in nitrogen deficient soils and thus depend on insects for sufficient nitrogenous nutrition
(c) They cannot synthesize certain vitamins themselves and depend on the insects digested by them
(d) They have remained in that particular stage of evolution as living fossils, a link between autotrophs and heterotrophs