The five classes of vertebrates are fish, amphibians, reptiles, mammals and birds. These groupings predate modern genetics and represent functional groupings rather than true trees of phylogeny. Bony fish, for example, are more closely related to mammals than they are to sharks.
Vertebrates are members of a sub-phylum within the phylum Chordata. The five vertebrate classes are grouped according to classical taxonomic lines rather than by clade, which is a true representation of each group's real relationship with the other groups of chordates. A clade consists of all descendants of a common ancestor. Thus, mammals and birds are good clades, as each group is descended from its own common ancestor, which was not ancestral to any other non-mammal or non-bird. Reptiles are a grade, not a clade, as some reptiles are more closely related to birds than they are to other reptiles. The same is true of amphibians, who are also not a true clade, as some descendants of their common ancestors are now reptiles, birds or mammals.
The four classes of air-breathing vertebrates are called tetrapods, and they have close relatives among bony fish. Tetrapods and bony fish are a good clade, as they are all exactly equally distant from the vertebrate outgroup of cartilaginous fish.Learn More
Harbor seals live on the northern coastlines of the Pacific and Atlantic oceans and in Arctic regions. Though they spend most of their time in the water, they often search for food along the coast, near the mouths of freshwater rivers and on island beaches and reefs.Full Answer >
Many animals feed on fruit, such as birds, fruit bats, mice, civets, deer and chimpanzees. Some animals subsist entirely on fruit while others, such as foxes, feed on a variety of foods including fruit.Full Answer >
The Trissolcus wasp is one of the few predators that eats stink bugs. The tiny wasp is smaller than a fruit fly but it can kill stink bug eggs. The wasp finds stink bug eggs, then plants eggs of its own inside the stink bug eggs. A larval wasp develops and eats the growing stink bug. The Trissolcus wasp could be useful as a national control for stink bugs.Full Answer >
Animals that live on land are called terrestrial animals. Animals such as cows, buffaloes, zebras, giraffes, lions, tigers and foxes are all terrestrial. Terrestrial animals are classified into mammals, reptiles, birds and insects; snakes and lizards are reptiles, while wolves, dogs and cats are mammals.Full Answer >