Tachyglossidae

The tachyglossidae or echidnas (Tachyglossidae) are the only known family of the suborder Tachyglossa, where current echidnas and their ancestors are classified extinct. These mammals, similar in appearance to sea urchins, inhabit the islands of New Guinea, Salawati, Australia, Tasmania and other smaller islands close to their coasts. In addition to being very difficult to find, their rarity lies in the fact that they are the only mammals, along with platypuses, that lay eggs.

Echidnas owe their name to the mythological nymph mother of all the legendary monsters of Classical Greece. Their bodies are covered in thorns, which together with their diet, mostly insectivorous, and in some cases with a predilection for ants and termites (myrmecophagy), has earned them the name "spiny anthills". Echidnas evolved between 20 and 50 million years ago, descending from a platypus-like monotreme. This ancestor was aquatic, but echidnas adapted to life on land.

Etymology

Echidnas are named after the Echidna, a creature from Greek mythology that was half-woman, half-serpent, as the animal was perceived to have both mammalian and reptilian qualities. An alternative explanation is a confusion with (from Ancient Greek: ἐχῖνος [ekhînos] 'urchin, sea urchin').

Area of the equidna

Taxonomy

There are currently two recognized living genera, with only four species:

• Gender Tachyglossus - Short or Australian snouts.
  • Tachyglossus aculeatus - Short or common snout.
• Gender Zaglossus - Long snout or New Guinea.
  • Zaglossus attenboroughi - Attenborough's Cluster.
  • Zaglossus bartoni - Barton's thigh.
  • Zaglossus bruijni - Common Zagloso or Bruijn.

Features

They are animals with a compact body, covered in dense fur from which long spikes protrude, used as a method of defense. Normally, they are between 35 and 45 centimeters long, with a 10 centimeter tail, and an average weight of 2 to 7 kilograms. Males are generally larger than females.

The skull is long and rounded, the face long with the lower jaw poorly developed, made up of two thin and long bones. Their diet, made up of insects and worms, determines a narrow-opening tubular mouth apparatus, equipped with a long sticky tongue that can reach 20 centimeters in length, with which they catch food, which, lacking teeth, will be crushed with some horny spines located on the palate at the end of the mouth. To locate food, in addition to a heightened sense of smell, they are endowed with tactile electroreceptors on their faces with which it is easy for them to find colonies of ants and termites.

They are powerful burrowers, using their hands and feet to build tunnels and cavities or dig into the ground in search of food. To do this, its extremities have digging hands and feet equipped with powerful nails. The second finger of the hind limbs is longer and is used for scratching and cleaning hair and skin.

Males and some females have spurs behind the knee joint, but unlike Ornithorhynchus sp., this animal does not synthesize any toxic substance, so the real function of these is unknown. the same.

Females develop a temporary pouch during incubation and lactation. The male penis has four heads, common among reptiles but rare in mammals. Despite being a mammal, the echidna hatchling hatches from eggs, as it is one of the two oviparous mammals, along with the platypus (Ornithorhynchus anatinus), that exist on Earth.

Contrary to popular belief, echidnas do not hibernate in response to cold. The state of torpor to which some isolated specimens are subjected seems to be more related to an anomalous digestive process.

Contrary to previous research, echidnas do enter REM sleep, though only when the ambient temperature is around 25 °C. At temperatures of 15 °C and 28 °C, REM sleep is suppressed.

Playback

The female lays a single egg. Incubation takes ten days; the young echidna sucks milk from the pores of the two mammary glands (monotremes do not have nipples) and remain in the pouch for forty-five to fifty days, at which time the spines begin to develop. The mother digs a burrow and deposits the young, returning every five days to nurse it until weaning, which is seven months.

Male echidnas have a four-headed penis, but only two of the heads are used during mating. The other two heads "close up" and they do not grow in size. The used heads are exchanged each time the mammal mates.