Waptia ovata, Unusual Shelled Arthropod from Chengjiang

Description: This unusual arthropod is known as Candaspis lavigata. This one has much soft tissue preserved, and is seen in lateral aspect. The discovery of the Chengjiang Biota by Hou Xian-guang in 1984 opened a window onto a remarkable array of lifeforms from what is termed 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.

The systematic position of this taxon has undergone several revisions. It was originally placed within the Ostracodiform genus Mononotella, then later referred to a new genus Chaundianella. More recent finds of remains other than the carapace have shown it to be similar to the Burgess Shale genus Waptia. While the species is known from other Lower Cambrian locations in Yunnan, Sichuan, Guizhou, and Shaanxi Provinces, only those from the Chengjiang Biota are known to show soft part preservation.