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

Museum Quality Chengjiang Biota Onychodictyon Lobopodian Fossil

Name: Onychodictyon ferox (Lobopodian)
Phylum Lobopodia
Geological Time: Early Cambrian (~525 million years ago)
Fossil is 40 mm long
Fossil Site: Chengjiang Maotianshan Shales - Quiongzhusi Section, Yu’anshan Member, Heilinpu Formation, Mafang Village, Anning, Yunnan Province, China

The discovery of the Chengjiang Biota in 1984 resulted in a clear window on what is known as the Cambrian Explosion. The diversity of soft-tissue fossils is astonishing: algae, medusiforms, sponges, priapulids, annelid-like worms, echinoderms, arthropods (including trilobites), hemichordates, chordates, and the first agnathan fish make up just a small fraction of the total. Numerous problematic forms are known as well, some of which may have represented failed attempts at diversity that did not persist to the present day.

Also see a super rare Lobopodian from the U.S. called Halluicgenia. See more Chengjiang Biota fossils at Fossil Mall.