Onychodictyon is a genus of extinct lobopodian known from the Lower Cambrian Chengjiang Maotianshan Shales in the Yunnan Province in China.[1] It was characterized by a stout body covered by fleshy papillae and pairs of sclerotized plates with spines,[2][1][3] representing part of the diverse "armoured lobopodians" alongside similar forms such as Microdictyon and Hallucigenia.[1]
The maximum length of Onychodictyon is 70 mm (2.8 in).[1] It has a resemblance to Microdictyon (net-like sclerite ornament)[4] but also Aysheaia and tardigrade (basally-fused terminal leg pair).[5] Each leg have a pair of curved claws that are thought to have aided Onychodictyon climb onto other organisms.[6] Onychodictyon sclerites appear to have molted with some specimens exhibiting perfectly conjoined plates from successive molts.[7]
Onychodictyon is represented by two species: O. ferox which has a pair of simple eyes and feathery antenniform appendages on its head;[3] and O. gracilis which has a blunt front end without evidence of any appendages.[1]