John Meszaros:

Anomalocaris group. going clockwise from the lower left, the animals are: Anomalocaris canadensis, Amplectobelua symbrachiata, Hurdia victoria, Opabinia regalis, Kerygmachela kierkegaardi, Schinderhannes bartelsi, Pambdelurion whittingtoni and Laggania cambria.

Lobopods. Clockwise from top: Microdictyon sinicum, Hallucigenia sparsa, Onychodictyon ferox and Aysheaia pedunculata. Note, by the way, that what appear to be “eyes” on Microdictyon, Hallucigenia and Onychodictyon are actually sclerotized armor plates.

The Onychodictyon (2004)

Phylum : Lobopodia
Class : Xenusia
Order : Scleronychophora
Family : Eoconchariidae
Genus : Onychodictyon
Species : O. ferox

  • Early Cambrian (525 Ma)
  • 6 cm long (size)
  • China (map)

The Lobopodians are small marine and terrestrial animals termed colloquially “velvet worms” or “worms with legs”. While all recent forms are terrestrial, most Lobopodians in the fossil record were marine creatures. Most fossils are from the Cambrian, before life moved ashore. Six named genera, each with a single species, are known from the Chengjiang Biota, making it Onychodictyon ferox artthe richest source of Lobopodian fossils.

Onychodictyon ferox is one of the most striking, and quite rare; as of 2004, only some 15 examples were known. The maximum length is 70 mm. It possesses a sclerotized head shield with 10 paired sclerotic plates, each associated with a pair of legs. Each leg has curved claws that are thought to have served the creature as an adaptation to crawling on other organisms. Onychodictyon ferox is most closely related to Aysheaia from the younger Burgess Shale fauna.

Onychodictyon fossil