Pancrustacea

Life-forms

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Protostomia
Cladus: Ecdysozoa
Cladus: Panarthropoda
Phylum: Arthropoda
Cladus: Pancrustacea
Cladi: Allotriocarida – Multicrustacea – Oligostraca
Name

Pancrustacea
References

Oakley, T.H., Wolfe, J.M., Lindgren, A.R. & Zaharoff, A.K. 2013. Phylotranscriptomics to bring the understudied into the fold: Monophyletic Ostracoda, fossil placement, and pancrustacean phylogeny. Molecular Biology and Evolution 30(1): 215–233. DOI: 10.1093/molbev/mss216 Open access. Reference page.
Regier, J.C., Shultz, J.W., Zwick, A., Hussey, A., Ball, B., Wetzer, R., Martin, J.W. & Cunningham, C.W. 2010. Arthropod relationships revealed by phylogenomic analysis of nuclear protein-coding sequences. Nature 463(7284): 1079–1083. DOI: 10.1038/nature08742 Reference page.

Links

Pancrustacea in the World Register of Marine Species [as synonym of Crustacea]

Pancrustacea is the clade that comprises all crustaceans, including the cladistically included hexapods (insects and relatives).[2] This grouping is contrary to the Atelocerata hypothesis, in which Hexapoda and Myriapoda are sister taxa, and Crustacea are only more distantly related. As of 2010, the Pancrustacea taxon is considered well accepted, with most studies recovering Hexapoda within Crustacea.[3] The clade has also been called Tetraconata, referring to having four cone cells in the ommatidia.[4] This name is preferred by some scientists as a means of avoiding confusion with the use of "pan-" to indicate a clade that includes a crown group and all of its stem group representatives.[5]
Molecular studies

A monophyletic Pancrustacea has been supported by several molecular studies,[6][7][8][9][10] in most of which the subphylum Crustacea is paraphyletic with regard to hexapods (that is, that hexapods, including insects, are derived from crustacean ancestors).

The evidence for this clade derives from molecular data and morphological characteristics. The molecular data consists of comparisons of nuclear ribosomal RNA genes, mitochondrial ribosomal RNA genes, and protein coding genes. The morphological data consists of ommatidial structures (see arthropod eye), the presence of neuroblasts, and the form and style of axonogenesis by pioneer neurons.[11][12]
Regier et al. (2005)

In a 2005 study of nuclear genomes Regier et al. suggest that Hexapoda is most closely related to Branchiopoda and Cephalocarida + Remipedia, thereby hexapods are "terrestrial crustaceans", thus supporting the Pancrustacea hypothesis that maxillopods are not monophyletic (in the following cladograms Maxillopoda subclasses are highlighted). In addition, there appeared some evidence against the Ostracoda monophyly: that Ostracoda subclass Podocopa may form a clade with Branchiura.[6]