New fossil remains- missing link in auditory evolution
A recent study published in journal Science shows the missing link in the auditory evolution in mammals. Hearing among mammals is aided by 3 small bones in the ear called the hammer, anvil and the stirrup bones. These delicate bones were absent in the earlier reptilian ancestors. Scientists have now found the missing link in the form of a new species’ fossil- ‘Origolestes lii’. Fossils of 6 individual animals were uncovered in north-eastern China. These lived 125 million years ago in the early Cretaceous period. The Origolestes were the size of rodents and also appeared like one. They co-existed with dinosaurs. The high resolution CT scan imaging of their remains revealed an absence of bone-on-bone contact, unlike the earlier species. This acts as evidence for the ‘decoupling’ hypothesis i.e. the decoupling of the chewing and hearing process among the proto-mammals improved both the functions.