LPG-1 was also discovered in the poison of equidnas
Small bone found 30 years ago can completely change what we knew about the evolution of equidnas and ornitorres.
Researchers talk about a evolutionary change “extremely rare” that you will have involved equidnas e Ornitorrincos.
Equidnas, common mammals in Australian fauna, are terrestrial animals that live in burrows. Australian and native mammals, also mammals, are semi-aquatic.
Both are one of the latest representatives of the oldest mammals on Earth. And so far, it has been believed that they had evolved from an earthly ancestor.
But these “relics” tune will have a different origin than scientists thought.
A new one, who (re) analyzed a small bone found 30 years ago, suggests that the ancestor of the equidnas and modern organizations was, after all, an animal semi-here.
And the paleontologists stayed confusing, As summarized.
Because whales or dolphins are examples of the dozens of mammals that have evolved from land animals to live entirely or partially in water – but there are almost no records of mammals that have evolved from aquatic animals to live full or partially on the ground.
“We are talking about a semi-aquatic mammal that has changed water for a terrestrial existence and although it is an event extremely rare, We thought that’s what happened to the equidnas, ”comments the main author of the study, Suzanne Hand.
This revelation has come thanks to a single humerus bone discovered in Victoria, Australia, in the early 1990s; The humerus bone – the bone of the upper arm between the shoulder and the elbow – is the only known bone that belongs to the extinct species, Kryoryctes cadburyi, Named in 2005, it remembers the.
On the surface, the bone seems to be more than one equidna, leading some paleontologists to suggest that it was an ancestor of the equidnna. Others suggest that it was a “Monotremato-Tronco” – An ancestor of both the equidnas and the organ.
With computed tomography and other digitization techniques, researchers discover that the internal structure of the fossil did not correspond to the light bones of the modern equids (What was a surprise): has a dense structure more similar to the bones of ORNITORRINCO.
The internal structure revealed that the ornitorrics have very thick bone walls and a very small cavity inside the bone to the bone marrow, while the equidnna have very thin bone walls.
“The fossil microstructure of Kryoryctes humerus It is more like the internal bone structure observed in the ornitorrics; Heavy bones act as ballast, allowing them to dive easily in search of food. This is also observed in other semi-aquatic mammals, ”explains Hand.
It is a discovery that can also help explain why equidnas have electrical receivers Highly sensitive at the tip of the nose – much less than the ornitorrics.
A equidna has its feet facing back, which it uses to dig. An organicorrinco also has rear paws, which we use as a rudder while nothing. And the equidennas are also known for having a diving reflection when they are in the water.
These characteristics can fit this new scientific hypothesis: the two animals will have a semi-aquatic ancestor.
