Platypus and echidna shoulder girdles are also unlike any other living mammal – they have bones and articulations that do not exist elsewhere in the mammalian class. The large scapula and humerus allow for massive digging muscles. Platypus limbs are held sideways out from their bodies, like a lizard. On the whole, platypuses are so well adapted that their skeletons have remained relatively unchanged since non-avian dinosaurs were around. By contrast all other mammals have straightened limbs which sit below their bodies. This is one of the features that the earliest mammals inherited from the reptilian ancestors they evolved from, and something that has never changed in the evolution of the platypus. One of the very many ways that platypus (and echidna) skeletons differ from every other living mammal is that they have bent elbows and knees, with their legs held out sideways from their bodies much like a lizard. Aside from their relatives the echidnas, and one species of dolphin, platypuses are the only mammals known to detect electricity.Īdult platypuses have no teeth (juveniles have five to six ( one is displayed in our Micrarium) but they are resorbed by the time they leave their burrows) – instead they mash their food up with horny pads inside the bill. This contains highly specialised receptors that can detect the miniscule electric impulses that are generated by the muscular contractions of their underwater invertebrate prey. These bony prongs are the scaffold which supports their extraordinary leathery bill. The front of a platypus’ skull resembles the pincers of an earwig.

Duck billed platypus skull