MUSEUM QUALITY Onychodictyon Lobopodian from Chengjiang

Onychodictyon ferox

Phylum Lobopodia

Geological Time: Early Cambrian (~525 million years ago)

Size: Onychodictyon: 53 mm long (if straight)

Fossil Site: Chengjiang Maotianshan Shales, Quiongzhusi Section, Yu’anshan Member, Heilinpu Formation, Mafang, Anning, Yunnan Province, China


Onychodictyon feroxDescription: The discovery of the Chengjiang Biota by Hou Xian-guang 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, Onychodictyon clawarthropods (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. The Lobopodians are small marine and terrestrial animals termed colloquially “velvet worms” or “worms with legs”. While all Recent forms are terrestrial, most fossil Lobopodians are Onychodictyon foot clawmarine, and are known primarily from the Cambrian. Six named genera, each with a single species, are known from the Chengjiang Biota, making it the richest source of fossils of the type on Earth. This is one of the most striking, and quite rare; as of Lobopodian2004, 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 bears curved claws which are thought to have served the creature as an adaptation to crawling on other organisms. It is most closely related to Aysheaia from the younger Burgess Shale. This one is very detailed, with the legs and scerotzed plates apparent. What is evn more interesting is that the anteriormost and posteriormost legs show the claws referred to earlier. There may even be more of the specimen entombed in the matrix, waiting for someone with the skill to free them after over a HALF BILLION years.

click fossil pictures to enlarge


l Paleontology & Fossils l Paleobiology and Geologic Timeline l
l Fossil Amber l Ammonite Fossils l Dinosaur and Reptile Fossils l Fossil Kits l
l Crinoids and Echinoderms l Fish Fossils l Fossil Dealers l Insect Fossils l Invertebrate Fossils l
l Plant Fossils l Stromatolites l Trace & Ichnofossils l Trilobite Fossils l Vertebrate Fossils l