Analysis of the fossil suggests that the only two egg-laying mammals, platypuses and land-based echidnas, both descended from ...

In a study published today in the science journal PNAS, the researchers describe how a single humerus bone discovered in Victoria in the early 1990s challenges the terrestrial ancestor theory.

There is one radius (R1) and one ulna (U1); these are the two bones that connect the wrist and elbow. There are two humerus bones (H1 and H2). The humerus connects the shoulder and the elbow.

In a study published in PNAS, the researchers describe how a single humerus bone discovered in Victoria in the early 1990s challenges the terrestrial ancestor theory. The humerus bone—which is ...