Homalozoa
Homalozoa (‘carpoids’; phylum Echinodermata) Extinct subphylum whose members have no trace of radial symmetry. The theca is depressed and asymmetrical. Homalozoa are known from Middle Cambrian to Middle Devonian rocks. There are three classes: Homostelea, Homoiostelea, and Stylophora. The affinities of the group have generated some controversy. The similarities between the larvae of some echinoderms and some chordates (Chordata) has led to the suggestion that the phyla are in some way related. Most recently, the Stylophora have been reassigned by R. P. S. Jeffries on morphological grounds to a new subphylum of primitive chordates, the Calcichordata. The matter remains unresolved.
More From encyclopedia.com
Middle Class , middle class. The middle class has been an influential and often enigmatic presence in British history since the early 19th cent. It first gained sus… middle , mid·dle / ˈmidl/ • adj. 1. at an equal distance from the extremities of something; central: the early and middle part of life middle and eastern Euro… Java man , Java man a fossil hominid of the Middle Pleistocene period, whose remains were found in Java in 1891. Petty Bourgeoisie , Bourgeoisie, Petty
The term petty bourgeoisie originally referred to the class of people involved in small-scale commercial enterprises who owned the… Hemichordata , Hemichordata (Stomochordata) A phylum first encountered in the Middle Cambrian Burgess Shale, British Columbia, Canada. The hemichordates are related… Depressive Disorders , The term “depressive disorders” refers to a large group of psychiatric conditions whose main characteristic is an abnormal feeling of depression. Thi…
You Might Also Like
NEARBY TERMS
Homalozoa