Toxodon

Thank you Nuno! From the 6v 200th Birth Anniversary of Charles Darwin, this stamp shows the extinct Toxodon cranium he purchased in Uruguay. Projectile points found in association with these remains have been taken as evidence for the demise of the species.

Here is the same cranium, flipped in view. This, and the stamp to the left were released for the 150th anniversary of the Natural History Museum.