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The platypus (Ornithorhynchus anatinus), sometimes referred to as the duck-billed platypus, is a semiaquatic, egg-laying mammal endemic to eastern Australia, including Tasmania. The platypus is the sole living representative or monotypic taxon of its family Ornithorhynchidae and genus Ornithorhynchus , though a number of related species appear ...
The sequencing of the platypus genome has also provided insight into the evolution of a number of monotreme traits, such as venom and electroreception, as well as showing some new unique features, such as monotremes possessing five pairs of sex chromosomes and that one of the X chromosomes resembles the Z chromosome of birds, [13] suggesting ...
While most modern mammals begin showing up in fossil records dating back 60 million years, monotremes are thought to have evolved around 130 million years ago. How the Platypus Uses Its Sixth ...
This contrasts with the modern platypus, where adults are entirely toothless. It has been theorized that the loss of teeth in the platypus was a geologically recent event, occurring only in the Pleistocene (after over 95 million years of tooth presence in the ornithorhynchid lineage) after the migration of the rakali ( Hydromys chrysogaster ...
Male platypuses have sharp spurs on their back legs shaped like a canine tooth. These hollow spurs measure 0.59 to 0.71 inches long and connect to crural glands in the animal’s upper thighs.
Figure 1:In mammals, the quadrate and articular bones are small and part of the middle ear; the lower jaw consists only of dentary bone.. While living mammal species can be identified by the presence of milk-producing mammary glands in the females, other features are required when classifying fossils, because mammary glands and other soft-tissue features are not visible in fossils.
Ornithorhynchoidea is a superfamily of mammals containing the only living monotremes, the platypus and the echidnas, as well as their closest fossil relatives, to the exclusion of more primitive fossil monotremes of uncertain affinity.
Dinosaurs evolved from more primitive reptiles in the aftermath of Earth's biggest mass-extinction event caused by extreme volcanism at the end of the Permian Period about 252 million years ago.