Monotremes, which include echidnas and platypuses, differ in many aspects of their biology from all other mammals. Most distinctly, they lay eggs into a transient pouch rather than give birth to ...

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.

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.

Monotremes, found only in Australia and New Guinea, are unique mammals that lay eggs, combining features of reptiles and mammals. This group includes the platypus and four echidna species.

Australian researchers have found evidence of the oldest known platypus and a new species, dubbed 'echidnapus', which has a platypus-like anatomy alongside features that more closely resemble an ...

For decades, scientists have known that platypuses and echidnas – Australia’s unique egg-laying mammals – have another developmental quirk: they don’t use the same genetic toolkit as other mammals to ...

MATTHEY1 investigated the cytology of the Monotremes and recognized a division into macro- and micro-elements similar to that in birds, and obtained a value of 70 ± 10 for the diploid number. Van ...

In almost all mammals, male sex-determination occurs via the SRY gene on the male Y chromosome. Monotremes have evolved a totally different sex chromosome system that lacks the SRY gene.

By Amanda Schupak, CNN (CNN) — The story of two of the strangest animals on the planet just got a little stranger, thanks to clues revealed by a lone fossil specimen that scientists now say ...