Another of the new species, Parvopalus clytei, is among the smallest monotremes ever found, roughly the size of a rat. The third, Dharragarra aurora , is the earliest known species of platypus.

As the world’s only surviving egg-laying mammals, Australasia’s platypus and four echidna species are among the most ...

Six monotremes living in the same place at the same time, 100 million years ago at Lightning Ridge, NSW. Clockwise from lower left: Opalios splendens, a newly described species dubbed an ...

A diverse assemblage of monotremes (Monotremata) from the Cenomanian Lightning Ridge fauna of New South Wales, Australia. Alcheringa: An Australasian Journal of Palaeontology , 2024; 1 DOI: 10. ...

A new study suggests the platypus and echidna — the only egg-laying mammals — had a water-dwelling ancestor. The finding could upend what’s known of their evolution.