The Australian Zoologist 20, part 1.Īugee, M. They extend far posteriorly in the skull (see 3D model), underlying the olfactory and cerebral cavities of the braincase.Īugee, M. Internally, the most prominent features are the turbinates. The lower jaw is reduced and has poorly developed coronoid and angular processes. The ectotympanic is oriented horizontally, and the external auditory meatus is directed ventrally. The palate extends back to the level of the ears.
The skull of Tachyglossus is characterized by an elongate, rounded snout and a laterally bulging braincase. The mouth is toothless and contains a long, sticky tongue. The most prominent feature on the head is the elongate, hairless snout. The legs are short and stout each ending in feet with five digits that terminate in elongated claws. The body is rounded and dorsoventrally compressed ending in a short tail. Ants and termites comprise the majority of the diet of this animal (Nowak, 1991).Įchidnas, also known as spiny anteaters, are covered by hollow spines that are essentially modified hairs. It rarely enters torpor during cold weather but rather uses shivering for thermoregulation. Tachyglossus is nocturnal and crepuscular in activity. The short-nosed echidna lives in a variety of terrestrial habitats and shelters in burrows or caves. The fossil record of echidnas is poor only extending back to the Pleistocene of Australia and New Guinea (Murray, 1978 Griffiths et al., 1991). Tachyglossus is native to Australia, Tasmania, and central and southern New Guinea. An alternative hypothesis based on molecular and morphological data places Monotremata as the sister taxon to Marsupialia (Gregory, 1947 Penny and Hasegawa, 1997). Most phylogenetic analyses based on morphological and molecular data place Monotremata as the sister taxon to Theria (Placentalia + Marsupialia) among the major clades of living mammals. Monotremes, or the egg-laying mammals, are named for the single common opening for the urogenital and digestive systems.
Tachyglossus aculeatus, the short-nosed echidna, is one of three extant members of Monotremata, the others being Zaglossus bruijni and Ornithorhynchus anatinus.
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