Published July 8, 2022 | Version v1
Taxonomic treatment Open

Placoparina dravidicus Whittard 1940

  • 1. Department of Earth Sciences, Museum of Natural History, Cromwell Road, London, SW 7 5 BD, UK.
  • 2. Department of Earth and Planetary Sciences, University of California, Riverside, CA 92521, USA. & Department of Geography and Environmental Studies, Texas State University, San Marcos, TX 78666, USA

Description

Placoparina ? dravidicus (Reed, 1915)

Fig. 13.2

1915 Cheirurus dravidicus; Reed, p. 48, pl. 8, fig. 12.

Material. Holotype: pygidium from Lower Naungkangyi Beds (probable Darriwilian) at Man-shio, Fig. 13.2 (Reed, 1915, pl. 8, fig. 12), GSI 11559.

Discussion. The species was described by Reed (1915) on the basis of one pygidium; a cast from the counterpart of the type specimen is illustrated here. Reed’s illustrations show the tips of the three pairs of pygidial spines. The anterior pair is not noticeably more strongly developed than the other two pairs, as it is in cheirurines, and the posterior pair is also prominent in P.? dravidicus. Lane (1971) showed that pygidia were the most informative sclerite in cheirurids, and it seems improbable that P. ? dravidicus is a cheirurine given its pygidial structure. Eccoptochile has a pygidium with three pairs of obtuse spines (type material of the type species in Horný & Bastl, 1970, pl. 14, fig. 1). The pygidium of Placoparina Whittard, 1940, is generally similar. However, the relatively obtuse lobes, and their marked fulcrum are more like those on Placoparina (Whittard, 1958) than Eccoptochile, and dravidicus is tentatively assigned herein to Placoparina. The identity of Reed’s species cannot confidently be resolved without further collections.

Notes

Published as part of Fortey, Richard A., Wernette, Shelly J. & Hughes, Nigel C., 2022, Revision of F. R. C. Reed's Ordovician trilobite types from Myanmar (Burma) and western Yunnan Province, China, pp. 301-356 in Zootaxa 5162 (4) on page 340, DOI: 10.11646/zootaxa.5162.4.1, http://zenodo.org/record/6810290

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Linked records

Additional details

Biodiversity

Collection code
GSI
Family
Cheiruridae
Genus
Placoparina
Kingdom
Animalia
Order
Phacopida
Phylum
Arthropoda
Scientific name authorship
Whittard
Taxon rank
genus
Type status
holotype
Taxonomic concept label
Placoparina Whittard, 1940 sec. Fortey, Wernette & Hughes, 2022

References

  • Reed, F. R. C. (1915) Supplementary Memoir on new Ordovician and Silurian fossils from the Northern Shan States. Palaeontologia Indica, New Series 6, 1 - 98.
  • Lane, P. D. (1971) British Cheiruridae (Trilobita). Monographs of the Palaeontographical Society, 530, 1 - 95.
  • Horny, R. & Bastl, F. (1970) Type specimen of fossils in the National Museum, Prague. Trilobita. National Museum, Prague, Prague, 354 pp.
  • Whittard, W. F. (1940) The Ordovician trilobite faunas of the Shelve-Corndon District, West Shropshire, Part 1. Annals and Magazine of Natural History, Series 11, 5, 153 - 172.
  • Whittard, W. F. (1958) The Ordovician trilobites of the Shelve inlier, west Shropshire. Monographs of the Palaeontographical Society, 1958, 71 - 116.