Detailed Chengjiang Biota Paleoscolex sinensis Worm

Description: This is an example of the nematomorph Paleoscolex sinensis. The species is known from numerous specimens, many of which have preserved details. This is a large worm (up to 100 mm) which at one point was thought to be an annelid, but more recently thought to either be a nematomorph or a member of an uncertain phylum. The intestine is often preserved as a dark film, but this one is more detailed than that.

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.

While the species is known only from Lower Cambrian locations in Yunnan Province, a congeric example is found in the slightly younger Kaili Formation of Guizhou Province, while another can be found outside of China as young as the Silurian., it is particularly well known from the Chengjiang Biota. With the recent designation of the Chengjiang Biota sites to UNESCO Word Heritage status only example such as this collected years ago will be available.

Also see: Chengjiang Biota Fauna List Chengjiang Fossils