Naraoiidae

Naraoia spinosa

• Burgess Shale, Canada
• Chengjiang Faunengemeinschaft, People's Republic of China

The Naraoiidae are a soft-shelled trilobitenähnliche Arthropodenfamilie, which occurred mainly in the lower and middle Cambrian. Finds usually come from the Burgess Shale of British Columbia and from the Maotianshan slate of the People 's Republic of China.

The taxonomic position of the Naraoiidae is uncertain. The trilobites are similar in some respects, but still have quite peculiar characteristics which distinguish them from the other Trilobitengruppen, such as their nichtmineralisiertes exoskeleton and its unsegmented plate. Some experts consider the Naraoiidae as genuine trilobites of the order Nectaspida, while others see them as trilobites uncertain assignment; Moreover, is shared by some researchers to believe that it could even be a non-related with the trilobite group of arthropods in the Naraoiidae.

Have been known, one of which Naraoia was first described and also gained the greatest recognition of several different genres. The type Naraoia Naraoia has a completely non-mineralized body covering and a unsegmented plate. Their maximum size is about 4 cm. The type longicaudata was placed in a separate genus Misszhouia. Tegopelte - another unreinforced trilobite, which also comes from the two shale formations - is sometimes made ​​to the Naraoiidae or obtains its own family, the Tegopeltidae.