Crustaceomorpha

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Crustaceomorpha
Temporal range: Cambrian to Recent
Nebalia bipes.jpg
Nebalia bipes, a leptostracan crustacean
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
(unranked): Crustaceomorpha
Chernyshev, 1960
Subphyla

Crustaceomorpha is a proposed clade of arthropods that includes crustaceans and numerous extinct groups. Synapomorphies for the clade are that the larval antenna is a feeding or locomotory organ, and there are six endopodal podomeres in post-antennal limbs.[1]

Extinct groups included in Crustaceomorpha vary considerably. It includes Agnostida (usually treated under Trilobita), Waptiida, Isoxyida, Phosphatocopida, and Bradoriida, among others. These primitive crustaceomorphs are grouped under Pseudocrustacea.[2][3]

The validity of Crustaceomorpha is controversial. It has more support among paleontologists who consider it a sister group to Arachnomorpha, which includes trilobites and chelicerates (see cladogram below). Both are grouped under Schizoramia, a clade of arthropods with biramous appendages.[3][4] In contrast, neontologists tend to support the Mandibulata clade, which groups members of Crustacea together with Hexapoda and Myriapoda.[4]

      Common ancestor ←      
             

Lobopoda


             
             

Uniramia


      Schizoramia      
             

Crustaceomorpha


             

Arachnomorpha





See also[edit]

References[edit]

  1. ^ Jan Bergström & Xian-Guang Hou (2005). "Early Palaeozoic non-lamellipedian arthropods". In Stefan Koenemann & Ronald A. Jenner. Crustacea and Arthropod Relationships. Taylor & Francis. pp. 75–93. doi:10.1201/9781420037548.ch4. ISBN 978-0-8493-3498-6. 
  2. ^ Mikko Haaramo. "Crustaceomorpha – crustaceans and related arthropods". Mikko's Phylogeny Archive. Retrieved January 22, 2012. 
  3. ^ a b S. M. Gon III. "Trilobite Systematic Relationships". A Guide to the Orders of Trilobites. Retrieved January 22, 2012. 
  4. ^ a b David A. Grimaldi & Michael S. Engel (2005). Evolution of the Insects. Cambridge University Press. p. 107. ISBN 978-0-521-82149-0.