Panarthropoda

Panarthropoda is a proposed animal clade containing the extant phyla Arthropoda, Tardigrada and Onychophora. Extinct panarthropods that do not belong to any of the modern phyla are classified in the paraphyletic taxon Lobopodia, which is sometimes expanded to include tardigrades and onychophorans as well. A close relationship between onychophorans and arthropods is widely agreed upon, but the position of tardigrades is more controversial. Some studies have found tardigrades to be more closely related to nematodes. Not all studies support the monophyly of Panarthropoda, but most do, including neuroanatomical, mitogenomic and palaeontological studies. Originally, they were considered to be closely related to the annelids, grouped together as the Articulata, but newer studies place them among the Ecdysozoa.
Common characteristics of the Panarthropoda include the presence of legs and claws, a ventral nervous system, and a segmented body.
"Sialomorpha", a genus of microinvertebrate discovered in Dominican amber in 2019 also belongs to this group, though its exact placement is uncertain.