Title: Egg
Content: with cooler temperatures favouring males. Not all reptiles lay eggs; some are viviparous ("live birth"). Dinosaurs laid eggs, some of which have been preserved as petrified fossils. Among mammals, early extinct species laid eggs, as do platypuses and echidnas (spiny anteaters). Platypuses and two genera of echidna are Australian monotremes. Marsupial and placental mammals do not lay eggs, but their unborn young do have the complex tissues that identify amniotes. The eggs of the egg-laying mammals (the platypus and the echidnas) are macrolecithal eggs very much like those of reptiles. The eggs of marsupials are likewise macrolecithal, but rather small,

Title: Ommatoiulus moreleti
Content: of South Australia, Victoria, Tasmania, Australian Capital Territory, southern New South Wales and Western Australia around Perth. Reproductive females mature their eggs during late summer-early autumn and may be seen mating during the autumnal activity period after which the female lays 60-80 eggs in a chamber 1–2 cm deep in the soil. The egg hatches to a pupoid stage, then develops by a series of moults up to 16 stages over 3 years. Males can be differentiated by the 8th and 12th stages but most are mature by the 10th or 11th stages. Females probably mature at similar stages. One-year-old

Title: Fauna of Australia
Content: species are nocturnal and many arboreal. Two of the five living species of monotreme occur in Australia: the platypus and the short-beaked echidna. The monotremes differ from other mammals in their methods of reproduction; in particular, they lay eggs instead of giving birth to live young. The platypus—a venomous, egg-laying, duck-billed amphibious mammal—is considered to be one of the strangest creatures in the animal kingdom. When it was first presented by Joseph Banks to English naturalists it was thought to be so strange that it was a cleverly created hoax. The short-beaked echidna is similarly strange, covered in hairy spikes

Title: Rosenberg's monitor
Content: 12-day period in January. In February and March, the female digs into a termite mound, creating a circular nest chamber. It lays up to 14 eggs. In September and October, the hatchlings emerge from the mound, generally with digging assistance from the adult. Its diet includes birds, reptiles, mammals, eggs, and carrion. Rosenberg's monitor Rosenberg's monitor, the heath monitor, or the southern heath monitor, Varanus rosenbergi, is a species of monitor lizards endemic to Australia, where it can be found in southern regions within the Australian Capital Territory, New South Wales, South Australia, Victoria, and Western Australia. The specific name,

Title: William Hay Caldwell
Content: With the assistance of the local Aborigines, Caldwell set up camp on the banks of the Burnett River in northern Queensland, hunting for lungfish, echidna, and platypus eggs. After extensive searching assisted by a team of 150 Aborigines, he discovered a few eggs. Mindful of the high cost per word, Caldwell famously but tersely wired London, "Monotremes oviparous, ovum meroblastic." That is, monotremes lay eggs, and the eggs are similar to those of reptiles in that only part of the egg divides as it develops. Caldwell stayed away from the beginning stages of Darwinism and wanted to study evolutionary patterns

Question: Which Australian mammal lays eggs?
Answer: Duck-billed platypus