The Collins’ monster, a spinous suspension-feeding lobopodian from the Cambrian Burgess Shale of British Columbia

Lobopodians, a paraphyletic group of Palaeozoic vermiform animals bearing metameric appendages, are key to the origin of extant panarthropods. First discovered in 1983 on Mount Stephen (Yoho National Park, British Columbia), the Cambrian (Wuliuan) Burgess Shale lobopodian nicknamed “Collins’ monster” is formally described as Collinsovermis monstruosus gen. et sp. nov. A formal systematic revision of the poorly known lobopodian Acinocricus stichus from Utah is also provided. The body of Collinsovermis is plump and compact, lacking space between lobopod pairs but shows the diagnostic suspension-feeding characters of luolishaniid lobopodians. The six anterior lobopod pairs are elongate, adorned with long and slightly curved ventral spinules arranged in a chevron-like pattern. The eight posterior lobopod pairs, which attach to a truncated body termination, are stout and smooth, each terminated by a single strong recurved claw. Each somite bears a pair of dorsal spines; somites 4 and posteri...