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Emucarididae
Emucarididae is an extinct family of soft-shelled trilobite-like arthropods (nektaspids) from the Lower Cambrian of South Australia and South China. It contains only two genera – ''Emucaris'' and ''Kangacaris''. Two species were described in 2010 from specimens recovered from Emu Bay Shale ''Lagerstätte'', one species in 2012 from the Maotianshan Shales. It is classified under the order Nektaspida, and is a sister-group to the families Liwiidae and Naraoiidae. Description The Emucarididae have a non-calcified exoskeleton that consists of an articulating head shield (or cephalon), thorax and tail shield (or pygidium), and there are no constrictions where these parts meet. The cephalon is semi-circular and has a straight back margin. The thorax consists of 3 or 4 narrow segments. The pygidium is 1-2× as long as the cephalon and has a distinct border furrow. The mouth plate (or hypostome) that sits on the belly-side of the cephalon is elongated and divided by a straight left-to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nektaspid
Nektaspida (also called Naraoiida, Nektaspia and Nectaspida) is an extinct order (biology), order of non-Mineralized tissues, mineralised artiopodan arthropods. They are known from the mid-Cambrian to the upper Silurian. Originally classified as trilobites, which they superficially resemble, they are now placed as close relatives as members of the Trilobitomorpha within Artiopoda. The order is divided into three major families; Emucarididae, Liwiidae, and Naraoiidae. Naming history and taxonomic placement The order was originally proposed by Raymond in 1920 as Nektaspia. 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, as do other modern works. Harry Blackmore Whittington, Whittington (1985) placed the order in the Trilobite, Trilobita. Cotton & Braddy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
