Debated, but probably from Ancient Greek ἔχιδνα (ékhidna, “snake, viper”) via Latin. Compare ἐχῖνος (ekhînos, “hedgehog, etc.”). However, this sense is problematic (unless it is a reference to the ant-eating tongue). The name perhaps belongs to Latin echinus from the aforementioned Ancient Greek term's alternate sense of "sea-urchin" (also "sharp points"), which Watkins explains as "snake-eater", from ekhis "snake." The 1810 Encyclopaedia Britannica deduces thus the animal's alternative name as "porcupine ant-eater".
Alternatively, and perhaps more likely, the name refers to Echidna as the name of a serpent-nymph in Greek mythology, "a beautiful woman in the upper part of her body; but instead of legs and feet, she had from the waist downward, the form of a serpent", in which case the animal was named for its mixed features (early naturalists doubted whether it was a mammal or amphibian). Ultimately, the etymology may be from a synthesis of all the roots above.
- Any of the species of small spined monotremes in family Tachyglossidae, the four extant species of which are found in Australia and southern New Guinea.
- Attenborough's long-beaked echidna (Zaglossus attenboroughi)
- Barton's Long-beaked echidna (Zaglossus bartoni)
- cyclops Long-beaked echidna (Zaglossus attenboroughi)
- eastern Long-beaked echidna (Zaglossus bartoni)
- long-beaked echidna (Zaglossus)
- short-beaked echidna (Tachyglossus)
- short-beaked echidna (Tachyglossus aculeatus)
- Sir David's long-beaked echidna (Zaglossus attenboroughi)
- western long-beaked echidna (Zaglossus bruijni)
echidna f (plural echidne)