Tetrapods: the four-limbed terrestrial vertebrates
What they are - meaning
Tetrapods are terrestrial vertebrate animals that have four limbs. These animals belong to the Tetrapoda superclass. Amphibians, mammals, reptiles and birds are tetrapods.
According to evolutionary biology, the first tetrapods emerged about 350 million years ago from freshwater lung fish. They quickly left the water to fetch food from the banks of rivers and lakes. In this movement, they used their thick fins to move around the earth. Over millions of years, these fins have been changing (evolving) for paws and limbs.
Summary of main characteristics of tetrapods:
- They have four members.
- They are vertebrate animals, that is, they have segmented spine and skull, whose function is to protect the brain.
- They are rope animals. They have complete digestive system, dorsal nerve tube and bilateral symmetry.
- Have nervous system, composed of brain and spinal cord.
- Amphibians: frogs, frogs, salamanders and tree frogs.
- Reptiles: turtles, alligators, crocodiles and lizards.
- Birds: chickens, ducks, mallards, geese, hawks, parrots, macaws, sparrows, pigeons, ostriches, toucans, hummingbirds, penguins, eagles, owls, among others.
- Mammals: humans, monkeys, horses, lions, giraffes, oxen, bats, mice, whales, zebras, cats, dogs, wolves, rhinos, platypuses, foxes, jaguars, oxen, buffalo, moose, reindeer, among others.
Additional information and curiosities:
According to evolutionary biology, the first tetrapods to emerge from the planet were amphibians. This occurred in the Devonian period, about 350 million years ago.
- Non-legged snakes and amphibians, although without limbs, are classified as tetrapods. This is because in the distant past these animals had limbs. Through a slow regression process, snakes and footless amphibians lost their limbs. Therefore, these animals are descended from a tetrapod and are therefore considered to belong to this animal superclass.
- Birds are considered tetrapods because their wings are considered by biology to be members.