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Amphibians have soft bodies with thin skins, and lack claws, defensive armour, or spines. Nevertheless, they have evolved various defence mechanisms to keep themselves alive. The first line of defence in salamanders and frogs is the mucous secretion that they produce. This keeps their skin moist and makes them slippery and difficult to grip.
Hatching takes place after 10 days of gestation; the young echidna, called a puggle, [23] [24] born larval and fetus-like, then sucks milk from the pores of the two milk patches (monotremes have no teats) and remains in the pouch for 45 to 55 days, [25] at which time it starts to develop spines. The mother digs a nursery burrow and deposits the ...
The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful (nomina dubia), or were not formally published (nomina nuda), as well as junior synonyms of more established names, and genera that are no longer considered amphibians. Modern forms are excluded from this list.
Scientists found that members of the new species are smaller than their offshore common bottlenose counterparts, eat different fish and have spines adapted to navigating the tight spaces of rivers ...
They have short vertebral columns, with no more than 10 free vertebrae and fused tailbones (urostyle or coccyx). [47] Frogs range in size from Paedophryne amauensis of Papua New Guinea that is 7.7 mm (0.30 in) in snout–vent length [ 48 ] to the up to about 35 cm (14 in) and 3.3 kg (7.3 lb) goliath frog ( Conraua goliath ) of central Africa ...
Class Amphibia (amphibians, some ancestral to the amniotes)—now a paraphyletic group; Class Synapsida (mammals and their extinct relatives) Class Sauropsida (reptiles and birds) While this traditional taxonomy is orderly, most of the groups are paraphyletic, meaning that the structure does not accurately reflect the natural evolved grouping. [47]
A neural spine sail is a large, flattish protrusion from the back of an animal formed of a sequence of extended vertebral spinous processes and associated tissues. Such structures are comparatively rare in modern animals, but have been identified in many extinct species of amphibians and amniotes. Paleontologists have proposed a number of ways ...
The use of the sail for thermoregulation, sexual dimorphism, and species identification are all hypotheses that have been applied to other sail-bearing taxa. [9] A speculation more specifically related to Platyhystrix is that these neural spines could have served to stiffen the vertebral column in order to adapt to a more terrestrial lifestyle ...