Nectaspida
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Liwiidae† |
The Nectaspida (also called Naraoiida, Nectaspia and Nektaspida) is an extinct order of soft-bodied arthropods proposed by Raymond in 1920; its taxonomic status is uncertain. Specimens are known from the early Cambrian to the upper Silurian periods. Whittington (1985) placed the order in the Trilobita. Cotton & Braddy (2000) place it in a new "Trilobite clade" containing the Trilobita, recognizing the close affinities of the Nectaspids to trilobites. Others consider the small number of genera in the Nectaspida unworthy of ordinal status.
[edit] Naming history
The order was originally proposed by Raymond in 1920 as Nectaspia. Størmer corrected it to Nectaspida for the 1959 Treatise on Invertebrate Paleontology to conform with the names of the other trilobite orders. Whittington described it in 1985 with the spelling Nektaspida; the revised 1997 Treatise by Raymond and Fortey uses this spelling.
[edit] External links
- Are Naraoids trilobites? -- photographs of specimens and discussion of classification controversy.
- Order Nectaspida -- more technical overview with references and descriptions of known genera.
