SYDNEY: Australia’s burrowing echidna advanced from a water-dwelling ancestor in an “extraordinarily uncommon” organic occasion, scientists stated on Tuesday (Apr 29) in a brand new research of the peculiar egg-laying mammals.
With highly effective digging claws, protecting spikes and extremely delicate beaks, echidnas are properly suited to a life shuffling by the forest undergrowth.
However a workforce of Australian and worldwide scientists imagine lots of the echidna’s uncommon traits have been first developed thousands and thousands of years in the past when its ancestors splashed by the water.
“We’re speaking a few semiaquatic mammal that gave up the water for a terrestrial existence,” stated palaeontologist Suzanne Hand, from the College of New South Wales.
“Whereas that might be an especially uncommon occasion, we expect that is what occurred with echidnas.”
Echidnas and one other Australian oddity, the semi-aquatic platypus, are believed to have advanced from a typical ancestor referred to as Kryoryctes cadburyi that lived in Australia greater than 100 million years in the past.
Researchers studied the one recognized bone fragment left by this ancestor, which was found amongst a trove of fossils at Dinosaur Cove in southern Australia some 30 years in the past.
Platypus bones have been much like this historical ancestor, Hand stated, with a thick and heavy construction that supplied ballast for diving.
Echidnas, as compared, had very skinny bone partitions that made it simpler to stroll on land, Hand stated.
This indicated echidnas have been descended from a water-dwelling ancestor however had advanced to reside on land, the analysis discovered.
It was way more frequent for prehistoric mammals to go from land to water, Hand stated, pointing in direction of seals, whales, dolphins and dugongs.
The researchers stated these findings seemed to be supported by different echidna traits.
Echidnas have backward-facing hind toes that assist them shift mounds of soil when burrowing.
These toes could have first developed as rudders serving to the echidna’s ancestor navigate fast-moving waterways, Hand stated.
Echidnas even have a “diving reflex” when submerged in water, which tells their physique to preserve oxygen serving to them maintain their breath for longer.
Echidnas and platypus are monotremes, a uncommon group of mammals that lay eggs as a substitute of reside younger.
“We’re hoping we’ll uncover different ancestral monotremes that can assist unravel the early historical past of this most fascinating group of mammals,” stated research co-author Michael Archer.
The analysis was revealed in peer-reviewed journal PNAS.
