Liwiidae is a family of

arthropod Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...

s in the order

Nektaspida Nektaspida (also called Naraoiida, Nektaspia and Nectaspida) is an extinct order of non- mineralised artiopodan arthropods. They are known from the lower-Cambrian to the upper Silurian. Originally classified as trilobites, which they superficiall ...

. Members are known from the

Cambrian The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordov ...

and

Ordovician The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era, and the second of twelve periods of the Phanerozoic Eon (geology), Eon. The Ordovician spans 41.6 million years f ...

periods.

Taxonomy

*'' Liwia'' Dzik and Lendzion, 1988 :*'' Liwia plana'' Lendzion, 1975 :*'' Liwia convexa'' Lendzion, 1975 *'' Soomaspis'' Fortey & Theron, 1995 :*'' Soomaspis splendida'' Fortey & Theron, 1995 *'' Tariccoia'' Hammann ''et al.'', 1990 :*'' Tariccoia arrusensis'' Hammann ''et al.'', 1990

References

Nektaspida Prehistoric arthropod families Cambrian first appearances Ordovician first appearances {{nektaspida-stub