Ancient aquatic origins of platypuses and echidnas uncovered
Recent research suggests that echidnas and platypuses originate from an aquatic ancestor, rather than a terrestrial one, as previously thought. New information has been provided by the analysis of a fossil from approximately 108 million years ago, which was discovered in Australia.
New studies indicate that echidnas and platypuses may have descended from an aquatic ancestor. Evidence of this origin comes from a fossil, roughly 108 million years old, discovered at Dinosaur Cove in Australia. These unique animals, known as monotremes, are classified as egg-laying mammals and may have evolved from an aquatic or semi-aquatic environment. Professor Suzanne Hand from UNSW emphasizes that while it is quite common for mammals to evolve from land to water, the reverse phenomenon is extremely rare.
Platypuses and echidnas are the only living mammals today that lay eggs. Platypuses, found in Australia and Tasmania, are known for their characteristic duck-like bill, whereas echidnas are covered in spines and resemble hedgehogs. After laying eggs, the female incubates them in a special pouch or depression on her belly, and after hatching, the young feed on milk that seeps through pores in the skin.
Groundbreaking research by Australian scientists
Research conducted by the University of New South Wales (UNSW) challenges previous theories. As reported by Science Alert, the analysis of the humerus bone, discovered by a team from Museums Victoria, indicates similarities to semi-aquatic animals, such as the platypus.
Is Kryoryctes cadburyi the key to understanding the past?
The humerus bone belonging to the extinct species Kryoryctes cadburyi was discovered in the 1990s. The object is unique as it is the only bone found of this species. Its internal structure resembles the bones of platypuses, suggesting that the ancestors of echidnas might have been semi-aquatic.
Scientists from UNSW used advanced scanning techniques to examine the internal structure of the bone. They discovered that this structure is more similar to platypuses than to echidnas, suggesting that the ancestors of echidnas might have adapted to life on land, losing the heavy bones characteristic of aquatic animals.
Searching for further evidence
Professor Michael Archer from UNSW emphasizes that studies on opalized fossils from Lightning Ridge could provide more information about the early history of monotremes. Scientists hope to discover more ancestors that may help unravel this fascinating evolutionary puzzle.
