''Pleuroctenium'' Hawle & Corda (1847) is an agnostid

trilobite Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the ...

belonging to the family

Condylopygidae The Condylopygidae Raymond (2013) RAYMOND, P. E., 1913: Some changes in the names of genera of trilobites. ''The Ottawa Naturalist'', 26: 137−142. are a family of small trilobites that lived during the Middle Cambrian, and found in Canada (New ...

Raymond (1913). The genus occurs in

Middle Cambrian Middle or The Middle may refer to: * Centre (geometry), the point equally distant from the outer limits. Places * Middle (sheading), a subdivision of the Isle of Man * Middle Bay (disambiguation) * Middle Brook (disambiguation) * Middle Creek ...

(

Drumian The Drumian is a stage of the Miaolingian Series of the Cambrian. It succeeds the Wuliuan and precedes the Guzhangian. The base is defined as the first appearance of the trilobite '' Ptychagnostus atavus'' around million years ago. The top is d ...

) strata of Canada (Newfoundland and New Brunswick), the Czech Republic, England and Wales, France, and Sweden.

Type species

By subsequent designation by Vogdes (1925) ''Battus granulatus'' Barrande, 1846, p. 15., from the Middle Cambrian of Bohemia. Lectotype: By subsequent designation by Snajdr (1958), National Museum of Prague, coll. Barrande, cc 250, No.1008; figured Barrande (1852, pl. 49, fig.5); Šnadjr (1958, pl. 2, fig. 5); and Horny & Bastl, 1970, p1. 1, fig. 6. From the Skryje Beds (Jince Fmn.), ''Eccaparadoxides pusillus'' Zone, Týřovice, Bohemia.

Distribution

* ''P. granulatum granulatum'' Barrande (1846) has been collected from the early Middle Cambrian of Canada (''Mawddachites hicksi'' Zone in the Manuels River Formation, South-East Newfoundland), the Czech Republic (higher levels of the Skryje Shales, Jince Formation, Skryje-Týřovice area), the ''"Paradoxides aurora"'' Zone to upper part of the ''Mawddachites hicksi'' Zone in the Abbey Shale Formation, Nuneaton, central England and from lower part of the ''Tomagnostus fissus'' Biozone within the Porth-y-rhaw Group, lower Menevia Formation of Dwrhyd, Nine Wells, near St David's, SW Wales. The Whitesands Bay Formation (lowest lithostratigraphic subdivision of the Porth-y-rhaw Group) of Rees et al,. (op. cit., P. 72) is conventionally referred to the biozone of ''"Paradoxides aurora"'' Salter, following Hicks (1881). However, that species is a probable junior subjective synonym of ''Mawddachites hicksii'', and so no independent ''aurora'' Biozone can be recognized. * ''P. granulatum scanense'' Westergard, 1946 (p. 35, pl.1, figs. 8-11 & pl.2, figs. 14-17). The holotype cephalon was figured by Westergard (''op. cit''., pl. 2, fig 14); from the ''Hypagnostus parvifrons'' Biozone, Andrarum, Scania). The subspecies is also recorded from the Menevia Formation (

) of Porth-y-rhaw, St David's Peninsula, SW Wales, Locs. OE-1 and PR-4 of Rees ''et al''., (''op. cit'' p. 26, Fig. 1.17 & p. 26, Fig. 1.18, respectively). * '' P. granulatum tuberculatum'' (Illing 1916, p. 421, pl. 33, figs. 4-8). The lectotype, SM A53055, is the specimen shown in Illing's (1916) fig. 7 of pl.33; selected and re-illustrated by Rushton (1979, p. 48, fig. 2H); from the Abbey Shale Formation, Hartshill Hayes, Nuneaton, ''T. fissus'' Biozone (horizon D3). Also recorded from the ''H. parvifrons'' Biozone, Menevia Formation in SW Wales, Loc PR-4 of Rees ''et al''., (''op. cit.'') and from the ''Mawddachites hicksii'' Zone and lower part of the ''P. davidis'' Zone in the Manuels River Formation of southeastern Newfoundland (Hutchinson 1962). * ''P. granulatum pileatum'' (Rushton 1966, p. 33, pl. 4, figs. 18 a-c), from the Purley Shale (c. 650' above base), ''Accadoparadoxides? pinus'' Zone, of Camp Hill, Stockingford, Nuneaton, Warwickshire, England. losest ICS interval: Cambrian Series 3 – Terreneuvian Epoch * ''P. bifurcatum'' (Illing 1916, p. 421, pl.33, figs. 2,3). Lectotype is SM A456, Illing's (1916) fig.2 of pl.33; selected and re-illustrated by Rushton (1979, p. 48, fig. 2C) and from the ''Ptychagnostus punctuosus'' Biozone (horizon G3), Abbey Shale Formation, Hartshill Hayes. The species occurs also in the Manuels River Formation of SE Newfoundland, uppermost part of the ''Paradoxides davidis'' Zone. ''P.'' cf. ''bifurcatum'' (listed as ''P. bifurcatum'') is recorded from the Menevia Formation of Porth-y-rhaw, SW Wales, ''Pt. punctuosus'' Biozone (Loc. PR-12 of Rees ''et al''. 2014, p. 27 & Fig. 1.18), and differs from ''bifurcatum'' (''s.s.'') in lacking the double row of three tubercles on the pygidium. Rushton (1979, p. 49) also mentioned a doubtful pygidium from Illing's Abbey Shales horizon G1, lowest horizon of the ''Pt. punctuosus'' Biozone at Nuneaton, which lacks the double row of tubercles on the axis, but which otherwise agrees with that of ''P. bifurcatum''. * ''P. magnificum'' Howell (1935) is from the Middle Cambrian of Hérault, Southern France.HOWELL B. F. 1935. Cambrian and Ordovician Trilobites from Hérault, Southern France. ''Journal of Paleontology'', Vol. 9, No. 3 (Apr., 1935), pp. 222-238.

References

{{Taxonbar, from=Q16988263 Condylopygoidea Agnostida genera Cambrian trilobites Fossils of the Czech Republic Fossils of Great Britain Fossils of France Fossils of Sweden Fossils of Canada Paleontology in Newfoundland and Labrador