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The skin of many frogs contains mild toxic substances called bufotoxins to make them unpalatable to potential predators. Most toads and some frogs have large poison glands, the parotoid glands, located on the sides of their heads behind the eyes and other glands elsewhere on their bodies. These glands secrete mucus and a range of toxins that ...
The features it shares with modern frogs include a forward-sloping ilium, the fusion of the frontal and parietal bones into a single structure known as the frontoparietal, and a lower jaw bone with no teeth. [11] Czatkobatrachus is another proto-frog with some characteristics similar to Triadobatrachus. It is from the early Triassic in Poland ...
Operculum (small bone in the skull, linked to shoulder girdle by the opercularis muscle; perhaps involved in hearing and balance; absent in caecilians and some salamanders, fused to the columella (ear bone) in most anurans) Loss of posterior skull bones (also in Microsauria and Dissorophoidea)
Adult frogs do not have tails and caecilians have only very short ones. [69] Didactic model of an amphibian heart. Salamanders use their tails in defence and some are prepared to jettison them to save their lives in a process known as autotomy. Certain species in the Plethodontidae have a weak zone at the base of the tail and use this strategy ...
The parietal eye is found in the tuatara, most lizards, frogs, salamanders, certain bony fish, sharks, and lampreys. [7] [8] [9] It is absent in mammals but was present in their closest extinct relatives, the therapsids, suggesting that it was lost during the course of the mammalian evolution due to it being useless in endothermic animals. [10]
Amniotes have the ability to procreate without water bodies. Because the amnion and the fluid it secretes shields the embryo from environmental fluctuations, amniotes can reproduce on dry land by either laying shelled eggs (reptiles, birds and monotremes ) or nurturing fertilized eggs within the mother ( marsupial and placental mammals ).
The critter’s robust skull had additional bones and elements that have likely disappeared with evolution, and its elongated snout paired with a short region of the skull behind the eyes was ...
Pig frogs are vertebrates, meaning they have a backbone, and they are tetrapods, meaning they have four limbs. They are adapted to living both on land and in water, and they are commonly found in the southeastern United States. Norwegian-American naturalist Leonhard Stejneger described the pig frog in 1901, and it still bears its original name ...