Weymouthia (trilobite)

Weymouthia
Temporal range: Lower Cambrian
linedrawing of Weymouthia nobilis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Trilobita
Order: Agnostida
Suborder: Eodiscina
Superfamily: Eodiscoidea
Family: Weymouthiidae
Genus: Weymouthia
Raymond, 1913
Type species
Agnostus nobilis
Ford, 1872
species
  • W. nobilis (Ford, 1872) ( syn.Agnostus nobilis
  • W. caudata (Delgado, 1904) (syn. Delgadella souzai caudata)
  • W. emerici Czarnocki
  • W. minor Egorova, 1961
  • W. tchernyshevae Egorova, 1961

Weymouthia is an extinct genus of eodiscinid agnostid trilobites, which lived at the end of the Lower Cambrian, in what are now the eastern United States, England, Siberia and China.

Description

Like all Agnostida, Weymouthia is diminutive and the headshield (or cephalon) and tailshield (or pygidium) are of approximately the same size (or isopygous) and outline. Like all Weymouthiidae, Weymouthia lacks eyes and rupture lines (or sutures). The headshield (or cephalon) is approximately as long as wide, lacks facial sutures and is eyeless. The tailshield (or pygidium) is about 1.2× as wide as long. Both are effaced except for a furrow close to their borders. The cephalic border bears lateral tubercles. The thorax consists of three segments.[1]

Etymology

Weymouthia is named after Weymouth, Massachusetts.[2]

Distribution

References

  1. Whittington, H. B. et al. Part O, Treatise on Invertebrate Paleontology. Revised, Volume 1 – Trilobita – Introduction, Order Agnostida, Order Redlichiida. 1997
  2. "Weymouth, MA, history". Retrieved 3 December 2012.
  3. Hinz, I. (1987). "The Lower Cambrian microfauna of Comley and Rushton, Shropshire, England". Palaeontographica Abteilung A 198 (1-3): 41–100. cited in Paleobiology Database. "Weymouthia nobilis".
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