Panarthropoda

Panarthropoda
Temporal range: Molecular clock and ichnofossils indicate a possible Ediacaran origin
Panarthropods include onychophorans such as Peripatopsis and arthropods such as polydesmid millipedes.
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Clade: ParaHoxozoa
Clade: Bilateria
Clade: Nephrozoa
Clade: Protostomia
Superphylum: Ecdysozoa
Clade: Panarthropoda
Nielsen, 1995
Phyla

Panarthropoda is a clade comprising the greatest diversity of animal groups. It contains the extant phyla Arthropoda (Euarthropoda), Tardigrada (water bears) and Onychophora (velvet worms), although the precise relationships among these remained uncertain according to studies published in 2023 and 2024. Panarthropods also include extinct marine legged worms known as lobopodians ("Lobopodia"), a paraphyletic group where the last common ancestor and basal members (stem-group) of each extant panarthropod phylum are thought to have risen. However the term "Lobopodia" is sometimes expanded to include tardigrades and onychophorans as well.

Common characteristics of the Panarthropoda include a segmented body, paired ladder-like ventral nervous system, and the presence of paired appendages correlated with body segments.