Maotianshan Shales fossil record. Phylum Porifera (sponges; 15 species) and Priapulida (16 species) are also well represented. Other phyla represented are Brachiopoda, Chaetognatha, Cnidaria, Ctenophora, Echinodermata, Hyolitha, Nematomorpha, Phoronida, and Chordata. Possible molluscs include "Wiwaxia" and "Nectocaris". About one in eight animals are problematic forms of uncertain affinity, some of which may have been evolutionary experiments that survived for only a brief period as benthic environments rapidly changed in the Cambrian. Chengjiang is the richest source of the lobopodia, a group including many early panarthropods, with six genera represented: "Luolishania", "Paucipodia", "Cardiodictyon"," Hallucigenia" (also known from the Burgess Shale), "Microdictyon", and "Onychodictyon".
Bacterial phyla Bacterial phyla The bacterial phyla are the major lineages, known as phyla or divisions, of the domain "Bacteria". In the scientific classification established by Carl von Linné, each bacterial strain has to be assigned to a species (binary nomenclature), which is a lower level of a hierarchy of ranks. Currently, the most accepted mega-classification system is under the three-domain system, which is based on molecular phylogeny. In that system, bacteria are members of the domain "Bacteria" and "phylum" is the rank below domain, since the rank "kingdom" is disused at present in bacterial taxonomy. When bacterial nomenclature was controlled under