World Library  
Flag as Inappropriate
Email this Article


Article Id: WHEBN0003628335
Reproduction Date:

Title: Eumalacostraca  
Author: World Heritage Encyclopedia
Language: English
Subject: Malacostraca, Eucarida, Lophogastrida, Mysida, Isopoda
Collection: Malacostraca
Publisher: World Heritage Encyclopedia


Atlantic blue crabs, Callinectes sapidus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Malacostraca
Subclass: Eumalacostraca
Grobben, 1892

Eumalacostraca is a subclass of crustaceans, containing almost all living malacostracans, or about 40,000 described species.[1] The remaining subclasses are the Phyllocarida and possibly the Hoplocarida.[2] Eumalacostracans have 19 segments (5 cephalic, 8 thoracic and 6 abdominal). This arrangement is known as the "caridoid facies", a term coined by William Thomas Calman in 1909. The thoracic limbs are jointed and used for swimming or walking. The common ancestor is thought to have had a carapace, and most living species possess one, but it has been lost in some subgroups.

Caridoid facies

Calman identified the following features as distinguishing eumalacostracan crustaceans:[3]

"Carapace enveloping the thoracic region; movably stalked eyes; biramous first antenna; scale-like exopod on the second antenna; natatory exopods on the thoracic limbs; elongate, ventrally flexible abdomen; tail fan formed by the lamellar rami of the uropods on either side of the telson."


Martin and Davis present the following classification of living eumalacostracans into orders, to which extinct orders have been added, indicated by †.[2]

The group as originally described by Karl Grobben[4] included the Stomatopoda (mantis shrimp), and some modern experts continue to use this definition. This article follows Martin and Davis in excluding them; they are placed in their own subclass, Hoplocarida.

Subclass Eumalacostraca Grobben, 1892


  1. ^ Gary C. B. Poore (2002). "Introduction". Crustacea: Malacostraca. Zoological catalogue of Australia. 19.2A.  
  2. ^ a b J. W. Martin & G. E. Davis (2001). An Updated Classification of the Recent Crustacea ( 
  3. ^ Hessler, Robert R. (1983). "A defense of the caridoid facies; wherein the early evolution of the eumalacostraca is discussed". In Schram, Frederick R. Crustacean Phylogeny (PDF). Rotterdam: A.A. Balkema.  
  4. ^  
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.