Summarizing Superphylum Deuterostomia

Summary

Echinoderms are deuterostomic marine organisms. This phylum of animals bears a calcareous endoskeleton composed of ossicles. These animals also have spiny skin. Echinoderms possess water-based circulatory systems. A pore termed the madreporite is the point of entry and exit for water into the water vascular system. Osmoregulation is carried out by specialized cells known as podocytes.

The characteristic features of Chordata are a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail. Chordata contains two clades of invertebrates: Urochordata (tunicates) and Cephalochordata (lancelets), together with the vertebrates in Vertebrata. Most tunicates live on the ocean floor and are suspension feeders. Lancelets are suspension feeders that feed on phytoplankton and other microorganisms.

Glossary

archenteron

primitive gut cavity within the gastrula that opens outwards via the blastopore

Chordata

phylum of animals distinguished by their possession of a notochord, a dorsal, hollow nerve cord, pharyngeal slits, and a post-anal tail at some point in their development

Echinodermata

phylum of deuterostomes with spiny skin; exclusively marine organisms

enterocoelom

coelom formed by fusion of coelomic pouches budded from the endodermal lining of the archenteron

madreporite

pore for regulating entry and exit of water into the water vascular system

water vascular system

system in echinoderms where water is the circulatory fluid