Clade of animals / From Wikipedia, the free encyclopedia

Nephrozoa is a major clade of bilaterians, divided into the protostomes and the deuterostomes, containing almost all animal phyla and over a million extant species. Its sister clade is the Xenacoelomorpha. The Ambulacraria (conventionally deuterostomes) was formerly[dubious ] thought to be sister to the Xenacoelomorpha, forming the Xenambulacraria as basal Deuterostomes, or basal Bilateria invalidating Nephrozoa and Deuterostomes in earlier studies.[1][2][3] The coelom, the digestive tract and excretory organs (nephridia), and nerve cords developed in the Nephrozoa.[4] It has been argued that, because protonephridia are only found in protostomes, they cannot be considered a synapomorphy of this group. This would make Nephrozoa an improper name, leaving Eubilateria as this clade's name.[5]

Quick facts: Nephrozoa Temporal range Ediacaran - Present...
Temporal range: Ediacaran - Present, 558–0 Ma
Diversity of nephrozoans
Scientific classification e
Kingdom: Animalia
Subkingdom: Eumetazoa
Clade: ParaHoxozoa
Clade: Bilateria
Clade: Nephrozoa
Jondelius et al. , 2002

Eubilateria Peter Ax, 1987


Chordates (which include all the vertebrates) are deuterostomes.[6] It seems very likely that the 555 million year old Kimberella was a protostome.[7][8] If so, this means that the protostome and deuterostome lineages must have split some time before Kimberella appeared — at least 558 million years ago, and hence well before the start of the Cambrian 538.8 million years ago.[6]


Xenacoelomorpha Proporus_sp.png


Chordata Common_carp_%28white_background%29.jpg

540 mya

Echinodermata Portugal_20140812-DSC01434_%2821371237591%29.jpg

Hemichordata Saccoglossus_kowalevskii_by_Spengel_1893.png


Ecdysozoa Long_nosed_weevil_edit.jpg

Spiralia Grapevinesnail_01.jpg

610 mya
650 mya