Cephalochordata (Gr., kephale, head; chorde, cord) is a sub-phylum within the phylum Chordata. The animals in this group are small, marine invertebrates. They are commonly called lancelets or amphioxi. Cephalochordates…
The sub-phylum Urochordata (Gr., uro, tail; chorde, cord) is a part of the phylum Chordata. The animals in this group are called sea squirts,or tunicates. These animals are very unique…
Phylum Hemichordata is generally considered the sister group of the phylum Echinodermata. The animals are marine deuterostomes. They are more or less worm-like, having the ancestral tripartite body of proboscis,…
Phylum Echinodermata represents the most advanced invertebrate phylum closer to the chordates. They vary substantially in size which may range from 1 cm to about 2 m in length. In…
Phylum Mollusca is the second largest invertebrate phylum containing more than 90000 described living species after phylum Arthropoda. Johnston has first coined the name Mollusca in 1650. Although Aristotle was…
In the phylum Arthropoda, there is the most number of animal species. The phylum Arthropoda contains more than 1079290 known species like Apis, Laccifer, Millipede, Palaemon, etc. The name Arthropoda…
The phylum Annelida is a group of organisms having ring-shaped segments. The term Annelida is derived from the Latin word; ” Annulus = ring “ There are more than 15000…
Aschelminthes is considered a superphylum, which includes many phyla. The term Aschelminthes was first introduced by Grobben in 1910. Earlier in 1859, Gegenbour was named Nemathelminthes for this phylum. So,…
In 1859 the scientist Gegenbaur proposed the name phylum platyhelminthes. Originally the animals of this group were placed in the taxon vermis by Linnaeus in 1735 along with other worms.…
Phylum Ctenophora and Phylum Cnidaria were in one phylum (phylum Coelenterata) in the early days. Later Coelenterata was divided into two separate phyla one is Cnidaria and the other is…