Leptochilodiscus

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Leptochilodiscus
Temporal range: Botomian (Olenellus-zone)
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Trilobita (?)
Order: Agnostida
Family: Weymouthiidae
Genus: Leptochilodiscus
Rasetti, 1966 [1]
Type species
Leptochilodiscus punctulatus
Rasetti, 1966
Species
  • Leptochiloduscus punctulatus Rasetti, 1966
  • Leptochilodiscus succinctus(Bassett et al., 1967)
Synonyms

Kerberodiscus Bassett et al., 1976

Leptochilodiscus [= Kerberodiscus Bassett et al., 1976] [2] is a genus of Lower Cambrian eodiscinid trilobite belonging to the family Weymouthiidae, [3] order Agnostida. [4] It lived during the Botomian stage = late Lower Cambrian Stage 4 (upper of two stages subdividing the un-named Series 2); the upper Botomian Stage boundary corresponds to base of both the Middle Cambrian Wuliuan stage and Miaolingian Series.

Contents

Type species

Leptochilodiscus punctulatus Rasetti, 1966, from the Late Lower Cambrian of New York State. Holotype: U.S.N.M. 146009. Paratypes: U.S.N.M. 146010 and 146011.

Distribution

Leptochilodiscus punctulatus Rasetti (1966, p. 26, Pl. 1, fig. 5 ; pl. 11, figures 1 - 7), the title erroneously printed Leptochilodiscus punctulatis [sic.], is part of a trilobite faunule that was collected from limestone beds which form several outcrops in a hillside on Griswold farm, about 1 mile southeast of North Chatham, Columbia County, New York State, USA; the faunule is referred to as the Acimetopus bilobatus faunule after one of the most common and characteristic trilobites. The Acimetopus bilobatus faunule is notable for the number and variety of trilobites of the family Eodiscidae.

Leptochilodiscus succinctus (Bassett et al., 1976, p. 632, pl. 2, figs. 11 a - c) was collected from the upper part of the Hells Mouth Formation, 16.5 m below the base of the overlying Trwyn y Fulfran Formation at Trwyn Carreg-y-tir (grid reference SH 2876 2402 ), Llŷn Peninsula, North West Wales . The fauna is of late lower Cambrian age and falls within the upper part of the protolenid-strenuellid Zone of the Comley Series of British nomenclature. [5] L. succinctus was originally described by Bassett et al., (op. cit.) as Kerberodiscus succinctus gen. et sp. nov.

Related Research Articles

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<i>Acidiscus</i> Extinct genus of trilobites

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<i>Acimetopus</i> Extinct genus of trilobites

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<i>Bathydiscus</i>

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<i>Ninadiscus</i>

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<i>Oodiscus</i>

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Stigmadiscus Rasetti, 1966, is a genus of Lower Cambrian Eodiscinid trilobite belonging to the family Weymouthiidae Kobayashi (1943) Order Agnostida It lived during the Botomian stage, = late Lower Cambrian Stage 4 ; the upper Botomian Stage boundary corresponds to base of both the Middle Cambrian Wuliuan stage and Miaolingian Series.

<i>Chelediscus</i> Genus of trilobites

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<i>Weymouthia</i> (trilobite) Extinct genus of trilobites

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<i>Litometopus</i> Extinct genus of trilobites

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<i>Pleuroctenium</i>

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<i>Condylopyge</i> Genus of trilobites

Condylopyge is a genus of agnostid trilobite that lived during the late Lower and early Middle Cambrian, in what are today Canada, the Czech Republic, England and Wales, France, Germany, Italy, Morocco, the Russian Federation, Spain, Turkey and Sweden. It can easily be distinguished from all other Agnostida because the frontal glabellar lobe is notably wider than the rear lobe. It belongs to the same family as Pleuroctenium but the frontal glabellar lobe does not fold around the rear lobe, as it does in that genus. Condylopyge is long ranging, possibly spanning the early Cambrian Terreneuvian Series in Nuneaton, central England into at least Drumian strata at various locations elsewhere.

Tannudiscus Pokrovskaya (1959) is a genus of eodiscinid trilobites belonging to the family Weymouthiidae Kobayashi T. (1943), Order Agnostida. It lived during the late Lower Cambrian, with remains found in Canada (Newfoundland), China (Gansu), The United Kingdom (England), and the Russian Federation.

Nicholas (1915) described the geology of St. Tudwal's Peninsula. He termed the oldest strata, exposed in the western cliffs of the peninsula, the 'Hell's Mouth Grits'. Bassett and Walton (1960) described the sedimentology and provenance, and Young et al., redescribed the rocks and formalized the formational names, newly retitling the 'Hells Mouth Grits' as the Hells Mouth Formation. Correlated lithologically with upper part of the Rhinog Formation in the Harlech Dome, the grit beds exposed at St Tudwal's are very uniform in lithology and thickness when traced along the outcrops, with a gradual thinning southwards. They exhibit the characteristic textures and structures of greywackes but differ from the normal type in being relatively well sorted and commonly laminated. Intercalated mudstones are more variable both in thickness and in lithology and contain laminated mudstones rich in sponge remains. The sandstones have sharply defined bases, often bearing sole structures and occasionally loaded. Sandstone dykes cut down from the bases of some beds and extend through up to 0.6 m of underlying siltstones. The sandstones may form sheets up to 4 m thick, although a bed thickness of up to 1m is more usual, and have been interpreted as turbidites deposited by currents from the northeast.

<i>Plutonides</i> Extinct genus of trilobites

Plutonides is a genus of Middle Cambrian trilobite in the family Paradoxididae with species Plutonides sedgwickii and possibly Plutonides? illingi. Several other species and subspecies were at times placed in Plutonides but have subsequently been moved to other genera.

<i>Serrodiscus</i> Extinct genus of trilobites

Serrodiscus Richter and Richter 1941. is a genus of eodiscinid trilobite belonging to the family Weymouthiidae Kobayashi T. (1943), Order Agnostida. It lived during the late Lower Cambrian, with remains found in Canada, China (Gansu), The United Kingdom (England), Germany (Silesia), Poland, the Russian Federation, and the United States. It is named for the spines on the ventral side of the pygidium, which give it a serrated impression.

<i>Bailiaspis</i> Genus of trilobites

Bailiaspis Resser, 1936, is a Middle Cambrian (Miaolingian) trilobite genus belonging to the Family Conocoryphidae Angelin, 1854. Within the Acado-Baltic region, the genus ranges from Wuliuan into Guzhangian age strata.

References

  1. RASETTI, F. (1966). "New Lower Cambrian trilobite faunule from the Taconic sequence of New York". Smithsonian Miscellaneous Collections. 148 (9): 1–52.
  2. BASSETT M. G., OWENS R. M., and RUSHTON A. W. A. 1976. Lower Cambrian fossils from the Hell’s Mouth Grits, St Tudwal’s Peninsula, North Wales. Journal of the Geological Society, 132 (6): 623–644. http://pubs.geoscienceworld.org/jgs/article-pdf/132/6/623/4885552/gsjgs.132.6.0623.pdf
  3. KOBAYASHI T. 1943. Brief notes on the Eodiscids 1, their classification with a description of a new species and a new variety, Proceedings of the Imperial Academy, Tokyo, Volume 19, pp. 37-42.
  4. SALTER, J. W. 1864: On some new fossils from the Lingula - flags of Wales. Quarterly Journal of the Geological Society of London, 20, 233 – 241.
  5. COWIE, J. W., RUSHTON , A. W. A. & STUBBLEFIELD, C. J. 1972. A correlation of Cambrian rocks in the British Isles. Geological Society of London, Special Report no. 2, 40 pp,