Xenocarida (from the
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
for ''strange shrimp'') is a proposed
clade inside the
subphylum
In zoological nomenclature, a subphylum is a taxonomic rank below the rank of phylum.
The taxonomic rank of " subdivision" in fungi and plant taxonomy is equivalent to "subphylum" in zoological taxonomy. Some plant taxonomists have also used th ...
Crustacea that comprises two classes that were discovered in the 20th century:
Remipedia
Remipedia is a class of blind crustaceans found in coastal aquifers which contain saline groundwater, with populations identified in almost every ocean basin so far explored, including in Australia, the Caribbean Sea, and the Atlantic Ocean. The ...
and
Cephalocarida
The Cephalocarida are a class in the subphylum Crustacea comprising only 12 benthic species. They were discovered in 1955 by Howard L. Sanders, and are commonly referred to as horseshoe shrimp. They have been grouped together with the Remipedi ...
. The clade was recovered as the sister groups to
Hexapoda
The subphylum Hexapoda (from Greek for 'six legs') comprises most species of arthropods and includes the insects as well as three much smaller groups of wingless arthropods: Collembola, Protura, and Diplura (all of these were once considered ins ...
(including
insects
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of j ...
).
However, other studies do not recover Xenocarida as a monophyletic group
and variously find
Branchiopoda
Branchiopoda is a class of crustaceans. It comprises fairy shrimp, clam shrimp, Diplostraca (or Cladocera), Notostraca and the Devonian ''Lepidocaris''. They are mostly small, freshwater animals that feed on plankton and detritus.
Description ...
or
Remipedia
Remipedia is a class of blind crustaceans found in coastal aquifers which contain saline groundwater, with populations identified in almost every ocean basin so far explored, including in Australia, the Caribbean Sea, and the Atlantic Ocean. The ...
as the hexapod sister group
[
]
References
Crustacean taxonomy
Protostome unranked clades
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