This includes kangaroos, wallabies, koalas, platypus, echidna, emu, kookaburras and dragon lizards. The duck-billed platypus and the echidna lay eggs in nests. The extant monotreme species are the platypus and four species of echidnas. Both the platypus and echidna species have spurs on their hind limbs. The other mascots were Millie the Echidna and Syd the Platypus. Hadrocodium are capable of laying eggs like today's platypus and echidna. A patella is also present in the living monotremes, the platypus and the echidna. Scientists generally use "platypuses" or simply "platypus". The exception to this are the egg-laying monotremes, the platypus and the echidnas of Australia. Unlike the modern platypus (and echidnas), "Teinolophos" lacked a beak. The modern platypus, a monotreme, appeared. Also terrestrial birds generally have a single ovary, as does the platypus, an egg-laying mammal. Modified sweat glands are what evolved into platypus venom glands. Bunyip eggs are allegedly laid in platypus nests. Although possessing mammary glands, the platypus lacks teats.