Verified answer

There are many, many more classifications of animals than just those:

Just within the (living) vertebrates (animals with backbones), there are the following classes:

Cephalaspidomorphi (jawless fish like lampreys and hagfish)

Chondrichthyes (rays, sharks and chimerae)

Actinopterygii (ray-finned bony fish)

Sarcopterygii (lobe-finned bony fish)

Amphibians

Reptiles (a waste-basket group including turtles, snakes, lizards, crocodiles, and the extinct dinosaurs, pterosaurs, plesiosaurs and icthyosaurs)

Aves (birds)

Mammals (vertebrates with a single bony mandible, three inner ear ossicles and nourish their young with milk - characteristically also have hair instead of scales)

But if you include the invertebrates, there are also the following Phyla:

Echinodermata (starfish, sea urchins, sea cucumber)

Rotifera (microscopic multi-cellular 'wheel animals')

Annelida (segmented worms such as earthworms, leeches)

Mollusca (snails, clams, sea slugs, octopus, squid)

Platyhelminthes (flatworms)

Arthropoda (insects, crustaceans, chelicerates)

Tardigrada (microscopic multi-cellular 'water bears')

Onychophora (velvet worms)

Nematoda (roundworms)

Cnidaria (jellyfish, sea anemone, hydra)

Porifera (sponges)

and that doesn't even include the weird ones like Bryozoa (moss animals), Phoronida, Nemertea, Rhombozoa, Hemichordata, Orthonectida and many others, or the extinct forms.

So there's way more than four classifications.

Amphibious Reptiles

Mammals

Your categories don't make sense. There are many classifications of animals (as I think were described above). Possibly you are reffering to their living habits, such as Aerial, Aquatic, Amphibious and Terrestrial? Otherwise, Reptiles are a type of vertabrate, and that opens a larger field of classifications - there are many vertabrate and invertabrate animals, and many other classes of animals besides reptiles.

It was mammal, reptile, and amphibian when I went to school but Al Gore has been very prolific of late, maybe he invented another classification.

Phylum Chordata includes Subphylum Vertebrata(Craniata) which inturn is divided into Superclasses. Superclass Gnathostomata includes Classes: Placodermi, Chondrichthyes(cartilaginous fish), Osteichthyes (bony fish), Amphibia, Reptilia, Aves & Mammalia.

If u want invertebrates then:

Protozoa(amoeba, paramecium)

Porifera(sea sponges)

Platyhelminthes(tape-worm, planarians)

Nematoda(round-worms, hook-worms,pin-worms)

Annelida(earthworms,leeches)

Arthropoda(insects, spiders-Arachnids, crustaceans, millipedes,

centipedes etc.)

Mollusca(snails,slugs, octopus,squids,Teredo, Pholas etc.)

Echinodermata(starfish, sea cucumbers, sea-lilies,feather-stars sea-urchins)

I'm not mentioning the sub-phylas for invertebrates.

It is class mammalia which includes animals with satisfy the conditions such as; they have hair, mammary glands, four chambered heart and give birth to live young ones.

MAMMALS

Includes kangaroos, anteaters, bats, monkeys, foxes, bears, otters, tigers, lions, seals, walrus, whales, manatees, elephants, zebras, rhinoceros, hippopotamus, giraffe, & antelopes

BIRDS

Includes penguins, pelicans, storks, flamingos, ibis, ducks, geese, eagles, hawks, vultures, pheasants, cranes, gulls, puffins, parrots, turacos, owls, hornbills, toucans, & starlings

REPTILES

Includes crocodiles, lizards, snakes, & turtles

AMPHIBIANS

Includes frogs, salamanders, & newts

BONY FISH

Includes coelacanths, lungfishes, gars, tarpon, eels, herring, catfishes, pike, salmon, lanternfishes, cod, anglerfishes, silversides, seahorses, scorpionfishes, perches, cichlids, tuna, flounders, & puffers

CARTILAGINOUS FISH

Includes sharks, skates, & rays

ECHINODERMS

Includes sea stars, sea cucumbers, & sea urchins

ARTHROPODS

Includes spiders, scorpions, shrimp, lobster, crabs, insects, millipedes, & centipedes

MOLLUSCANS

Includes clams, snails, octopuses, & squid

CNIDARIANS

Includes jellyfish, sea anemones, & corals

Mammals, but you forgot one of the classifcations, Insects.

The premise of the question is incorrect. The question is moot.