Liwia

Liwia is a genus of liwiid nektaspid.^[1] It includes the species Liwia plana and Liwia convexa, both known from borehole samples several kilometers in depth from the Zawiszyn Formation in Poland, which has also yielded Peytoia infercambriensis.

Liwia Temporal range: Early Cambrian 520–516 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Reconstruction
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Clade:	†Artiopoda
Order:	†Nektaspida
Family:	†Liwiidae
Genus:	†Liwia Dzik and Lendzion, 1988
Species
Liwia plana Lendzion, 1975 Liwia convexa Lendzion 1975

Discovery and naming

The holotype of fossil of Liwia was found from the Zawiszyn Formation of Poland, and described in 1975.^[2]

The original generic name Livia is derived from the name of the Liwiec River, near to where the fossils were found,^[2] although as this generic name was already preoccupied, it was changed in 1988 to Liwia. ^[3]

The specific name for L. convexa derives directly from the Latin word convexa, to mean "rounded", relating to the curved appearance of the pygidium; whilst the specific name for L. plana derives directly from the Latin word plana, to mean "flat", relating the overall flatness of this species.^[2]

Description

Liwia is a genus of nektaspida, and the namesake of the Liwiidae family, growing to around 20–30 mm (0.8–1.2 in) in length, with the longer, incomplete species being L. convexa; and the shorter, more complete species being L. plana.^[2]

They have a oval shaped cephalon, with four thoracic segments, and a distinctive spiked pygidium, of which there are six pairs of rear-facing spines, with the three anterior spines being shorter, whilst the three posterior spines are longer.^[2]