are large, flat, amoeba-like creature up to 0.078 in (2 mm) in diameter; the grayish white body of the organism consists of several thousand cells that form two epithelia but are not organized into tissues and organs.
Placozoa
Although most of the animal phyla are included in the deuterostomes and protostomes, cnidaria, porifera, placozoa and ctenophora are not included in the group of animals know as Bilateria (which contains the deuterostomes and protostomes). Cnidarians and ctenophores are in a group called Radiata, and Porifera and Placozoa are in the group known as Parazoa.
The animal kingdom is divided into five groups for classification purposes. They are called Ctenophora, Porifera, Placozoa, Cnidaria, and Bilateria.
actually seven of the 9 phyla use extracellular digestion. the two that are intracellular are porifera and placozoa
Some of the major phyla in the animal kingdom include Porifera (sponges), Cnidaria (jellyfish, corals), Platyhelminthes (flatworms), Annelida (segmented worms), Mollusca (snails, clams), Arthropoda (insects, spiders), Echinodermata (starfish, sea urchins), and Chordata (vertebrates and close relatives).
Some phyla within the kingdom Animalia include Chordata, Arthropoda, Mollusca, Annelida, and Echinodermata. Each phylum represents a distinct group of organisms with specific characteristics and traits.
Often there is a consensus of just over 30. Some 'splitter' taxonomists have higher estimates, with Edward O. Wilson suggesting 85. The ones that most people recognise include: Porifera Placozoa Cnidaria Ctenophora Nematomorpha Nemertea Nematoda Annelida Rotifera Platyhelminthes Cycliophora Gastrotricha Loricifera Hemichordata Sipuncula Priapulida (may have been demoted to a class) Entoprocta Ectoprocta Mollusca Arthropoda Urochordata Echinodermata Cephalochordata Chordata
Animals (the animal kingdom), by definition, are multicellular and heterotrophic. Animals cannot produce their own food. They feed on other organismal sources for their energy. They feed on plants or other animals. Thus be their definition of heterotrophic. All animals (whether Chordata, Echinodermata, Porifera, Placozoa, Annelida or Arthropoda) are all heterotrophic and all multicellular. Even tiny things like placozoans and rotifers are multicelled.Fungi cannot produce their own food either. Thus they may be called heterotrophic. They acquire their food by growing in it. Thus they acquire the label saprophytic as well. The fungal kingdom features both unicellular and multicellular organisms. Toadstools, mushrooms, bread mould, fruit mould and such are those that are multicellular.
Animals (the animal kingdom), by definition, are multicellular and heterotrophic. Animals cannot produce their own food. They feed on other organismal sources for their energy. They feed on plants or other animals. Thus be their definition of heterotrophic. All animals (whether Chordata, Echinodermata, Porifera, Placozoa, Annelida or Arthropoda) are all heterotrophic and all multicellular. Even tiny things like placozoans and rotifers are multicelled.Fungi cannot produce their own food either. Thus they may be called heterotrophic. They acquire their food by growing in it. Thus they acquire the label saprophytic as well. The fungal kingdom features both unicellular and multicellular organisms. Toadstools, mushrooms, bread mould, fruit mould and such are those that are multicellular.
* Trilobozoa * Porifera * Placozoa * Vendobionta * Cnidaria* Myxozoa * Ctenophora * Acoelomorpha * Orthonectida * Dicyemida * Gnathostomulida * Cycliophora * Micrognathozoa * Rotifera * Acanthocephala * Gastrotricha* Platyhelminthes * Phoronida * Brachiopoda* Bryozoa * Entoprocta * Nemertea * Sipuncula * Mollusca * Hyolitha * Echiura * Annelida * Chaetognatha * Nematoda * Nematomorpha * Priapulida * Kinorhyncha * Loricifera * Onychophora * Tardigrada * Arthropoda * Vetulicolia * Xenoturbellida * Echinodermata * Hemichordata* Chordata Sometimes, are considered invertebrates also Kingdom Protozoa (not true animals), which phyla are:* Amoebozoa * Choanozoa * Cercozoa * Foraminifera * Radiozoa * Apusozoa * Loukozoa * Percolozoa * Euglenozoa * Metamonada * Myzozoa * Ciliophora * Heliozoa
The Major phylums in the animal kingdom are as follows.INVERTEBRATESPhylum: PoriferaPhylum: Coelenterata/ CnidariaPhylum: PlatyhelminthesPhylum: Nematehelminthes/ AschelminthesePhylum: AnnelidaPhylum: ArthropodaPhylum: MolluscaPhylum: Echinodermata.The phylum protozoa is now not treated as animal phylum and it is included under a separate kingdom called PROTISTA.There are animals which are intermediate between invertebrates and vertebrates and are called protochordates.PROTOCHORDATESPhylum: Hemichordataphylum: VERTEBRATA, under this phylum there are six classesclass: Piscesclass: Amphibiansclass: Reptiliaclass: Avesclass: MammaliaAll the above are mojor phylums, along with these phylums, there are many minor phylums.
There are far too many invertebrate species to list. Note that there are far more invertebrate species than vertebrate species. However, I here are a list of invertebrate phyla: Acanthocephala (a phylum of worm) Acoelomorpha (a phylum of worm) Annelida (a phylum of worm) Arthropoda (spiders, crabs, etc) Brachiopoda Bryozoa Chaetognatha (a phylum of worm) Cnidaria (corals, sea anemones, jellyfish, etc) Ctenophora (comb jellies) Cycliophora Echinodermata (sea urchins, starfish, etc) Echiura (a phylum of worm) Entoprocta (a phylum of worm) Gastrotricha Gnathostomulida (a phylum of worm) Hemichordata (a phylum of worm) Kinorhyncha Loricifera Micrognathozoa Mollusca (octopi, clams, etc) Nematoda (a phylum of worm) Nematomorpha (a phylum of worm) Nemertea (a phylum of worm) Onychophora (a phylum of worm) Orthonectida Phoronida (a phylum of worm) Placozoa Platyhelminthes (flat worms) Porifera (sponges) Priapulida Rhombozoa Rotifera Sipuncula Tardigrada (Water bears, which are microscopic animals that live in and eat moss. They look like caterpillars). Xenoturbellida (strange flatworm)