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]
W. nobilis occurs in the Lower Cambrian of Massachusetts (Hoppin Slate, North Attleboro), and of the United Kingdom (Comley Quarry, Comley, 52.6° N, 2.8° W).[3]
Remarksedit
Fletcher & Theokritoff (2008) [4] designated Shaw's (1950, pl. 79, fig. 24) [5] specimen of “ Weymouthia nobilis (Ford, 1872)” [6] as the holotype of a new species, Serrodiscus weymouthioides, and considered Runcinodiscus Rushton (in Bassett et al., 1976) [7] [= ?Weymouthia nobilis (Ford, 1872)] to be a junior synonym of Serrodiscus; Rushton (1976) had previously regarded Weymouthia and Runcinodiscus as closely allied with Serrodiscus. Weymouthia nobilis (Ford 1872), first described from the Taconic region of New York State, is also recorded from the Protolenus Limestone (Ac5) [Protolenid-Strenuellid Zone] at Comley, Shropshire, England (Cobbold 1931),>[8] but Rushton (in Bassett et al., 1976, p. 637) showed that the English specimens are specifically distinct from W. nobilis as described by Ford (1872), and thus erected his new genus and species, Runcinodiscus index Rushton (in Bassett et al. 1976, p. 636-7).
Referencesedit
^WHITTINGTON, H. B. et al. Part O, Treatise on Invertebrate Paleontology. Revised, Volume 1 – Trilobita – Introduction, Order Agnostida, Order Redlichiida. 1997
^"Weymouth, MA, history". Retrieved 3 December 2012.
^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".
^FLETCHER, T. P. & THEOKRITOFF, G., 2008. The Early Cambrian of eastern Massachusetts. Northeastern Geology and Environmental Science, 30, 301-329.
^SHAW, A. B., 1950. A revision of several Early Cambrian trilobites from eastern Massachusetts. Journal of Paleontology, 24, 577-590.
^FORD, S. W., 1872. Descriptions of some new species of primordial fossils. American Journal of Science, Series 3, 3, pp. 419-422.
^BASSETT M. G., OWENS R. M., and RUSHTON A. W. A. 1976. Lower Cambrian fossils from the Hell’s Mouth Grits, Journal of the Geological Society, 132 (6): 623 – 644.
^Cobbold, Edgar Sterling (March 1931). "Additional Fossils from the Cambrian Rocks of Comley, Shropshire". Quarterly Journal of the Geological Society. 87 (1–4): 459–512. doi:10.1144/GSL.JGS.1931.087.01-04.17. S2CID 129469096.
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weymouthia, trilobite, weymouthia, extinct, genus, eodiscinid, agnostid, trilobites, which, lived, lower, cambrian, what, eastern, united, states, england, siberia, china, weymouthiatemporal, range, lower, cambrian, preꞒ, nllinedrawing, weymouthia, nobilisscie. 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 WeymouthiaTemporal range Lower Cambrian PreꞒ Ꞓ O S D C P T J K Pg NLlinedrawing of Weymouthia nobilisScientific classificationKingdom AnimaliaPhylum ArthropodaClass TrilobitaOrder AgnostidaFamily WeymouthiidaeGenus WeymouthiaRaymond 1913Type speciesAgnostus nobilisFord 1872SpeciesWeymouthia nobilis Ford 1872 syn Agnostus nobilis Weymouthia caudata Delgado 1904 syn Delgadella souzai caudata Weymouthia emerici Czarnocki Weymouthia minor Egorova 1961 Weymouthia tchernyshevae Egorova 1961 Contents 1 Description 2 Etymology 3 Distribution 4 Remarks 5 ReferencesDescription editLike 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 editWeymouthia is named after Weymouth Massachusetts 2 Distribution editW nobilis occurs in the Lower Cambrian of Massachusetts Hoppin Slate North Attleboro and of the United Kingdom Comley Quarry Comley 52 6 N 2 8 W 3 Remarks editFletcher amp Theokritoff 2008 4 designated Shaw s 1950 pl 79 fig 24 5 specimen of Weymouthia nobilis Ford 1872 6 as the holotype of a new species Serrodiscus weymouthioides and considered Runcinodiscus Rushton in Bassett et al 1976 7 Weymouthia nobilis Ford 1872 to be a junior synonym of Serrodiscus Rushton 1976 had previously regarded Weymouthia and Runcinodiscus as closely allied with Serrodiscus Weymouthia nobilis Ford 1872 first described from the Taconic region of New York State is also recorded from the Protolenus Limestone Ac5 Protolenid Strenuellid Zone at Comley Shropshire England Cobbold 1931 gt 8 but Rushton in Bassett et al 1976 p 637 showed that the English specimens are specifically distinct from W nobilis as described by Ford 1872 and thus erected his new genus and species Runcinodiscus index Rushton in Bassett et al 1976 p 636 7 References edit WHITTINGTON H B et al Part O Treatise on Invertebrate Paleontology Revised Volume 1 Trilobita Introduction Order Agnostida Order Redlichiida 1997 Weymouth MA history Retrieved 3 December 2012 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 FLETCHER T P amp THEOKRITOFF G 2008 The Early Cambrian of eastern Massachusetts Northeastern Geology and Environmental Science 30 301 329 SHAW A B 1950 A revision of several Early Cambrian trilobites from eastern Massachusetts Journal of Paleontology 24 577 590 FORD S W 1872 Descriptions of some new species of primordial fossils American Journal of Science Series 3 3 pp 419 422 BASSETT M G OWENS R M and RUSHTON A W A 1976 Lower Cambrian fossils from the Hell s Mouth Grits Journal of the Geological Society 132 6 623 644 Cobbold Edgar Sterling March 1931 Additional Fossils from the Cambrian Rocks of Comley Shropshire Quarterly Journal of the Geological Society 87 1 4 459 512 doi 10 1144 GSL JGS 1931 087 01 04 17 S2CID 129469096 nbsp This Agnostida related article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Weymouthia trilobite amp oldid 1160864356, wikipedia, wiki, book, books, library,
