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.

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.