Zaglossus or long-beaked echidnas, is a genus of echidnas that occur in New Guinea. There are three living species and two extinct species in this genus. The extinct species were present in Australia. Echidnas are one of the two types of mammals that lay eggs, the other being the platypus. The echidnas are a part of a very small group of surviving descendants of the earliest types of mammals; they retain many reptilian features such as egg-laying but display mammalian features such as fur and lactation. As such they were one of the first surviving mammals to clearly show a snap-shot of macroevolution in action.