A new dinosaur species, whose weight was similar to a parrot’s and had only one digit, has been discovered. Scientists view the rare solitary digit as evidence that the evolution of dinosaurs was more complex than they first believed. The dinosaur’s fossilised remains were found in rocks formed from 84 million to 75 million years ago in Linhe, a city near the Yellow River in China.
It belongs to a family within the carnivorous dinosaurian group theropods that later gave rise to modern birds. The new dinosaur – called Linhenykus, named after Linhe in Inner Mongolia – most likely grew to a few feet tall and weighed only as much as a large parrot. Linhenykus was discovered by an international team of scientists, led by Xu Xing of the Institute of Vertebrate Palaeontology and Paleoanthropology.
Its singer claw on the upper limbs may have been used to dig out insects like ants, said the scientists in a report published in the Proceedings of the National Academy of Sciences. Xu and others believe theropod dinosaurs started with five fingers but evolved to have only three fingers and some eventually became birds. Scientists think that, in the course of evolving into birds, various related dinosaur species gradually lost two of their five fingers, likely in response to changes in the environment.
But in recent decades, with the discovery of more theropods that have fewer than three fingers, like the two-finger Tyrannosaurus, scientists agreed that the evolution of dinosaurs’ hands was brought about more by random mutations than by basic adaptive evolution.
“Vestigial structures, like legs in whales and snakes, may appear and disappear seemingly randomly in the course of evolution,” said Jonah Choiniere of the Paleontology division at the American Museum of Natural History.
Source: China Daily