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Clarella venusta (Billings, 1872) (Fig. 16) Anapolenus venustus Billings, 1872: 474-476, fig.11;1874: 73, 74, fig.42. Clarella venusta – Hutchinson 1962: 111, 112, pl. 17, figs 7-10. — Martin & Dean 1988: 19, pl. 1, fig. 13. — Whittington et al. 1997: figs 308.1a, b. — Fletcher 2006: pl. 34, fig. 11 (partim). LECTOTYPE. — Specimen GSC No. 284a, Geological Survey of Canada, Ottawa, Canada, designated as lectotype by Whittington et al. (1997). From Chapel Arm, Trinity Bay, Newfoundland, Canada. DIAGNOSIS. — Glabella not reaching anterior margin; L4 short; eye lobes from L1 to S4; pygidium with two pairs of short marginal spines. MATERIAL EXAMINED. — Three cranidia of Clarella venusta (NFM F-3069; NFM F-3548; NFM F-3657). All specimens range between 16.25 and 16.27 m (Fig. 2) within the Manuels River Formation, type locality, Conception Bay South, Newfoundland, Canada. OCCURRENCE. — Clarella venusta is rare in the middle Cambrian and only reported from southeastern Canada, eastern Newfoundland, in the Paradoxides hicksi and Paradoxides davidis zones (Hutchinson 1962; Martin & Dean 1988; Fletcher 2006). DESCRIPTION The cranidium (NFM F-3096) is 22.2 mm in width and 15.8 mm in length. The width of the glabella is 10.3 mm and the length is 10.8 mm. Due to the preservation of NFM F-3548; NFM F-3657 a solid measurment was not possible. The three cranidia are preserved as one disarticulated internal cast and two moulds. REMARKS The cranidium of Clarella venusta is similar to Clarella impar (Hicks, 1872). The palpebral lobes of C. venusta are narrower and curved more sigmoidally than those of C. impar (Cook, 1997). The librigena illustrated by Fletcher (2006: pl. 34, fig. 12) is disarticulated and its suture of the librigena does not match that of C. venusta. It is here excluded from the species., Published as part of Unger, Tanja, Hildenbrand, Anne, Stinnesbeck, Wolfgang & Austermann, Gregor, 2022, Biostratigraphy and taxonomy of polymerid trilobites of the Manuels River Formation (Drumian, middle Cambrian), Newfoundland, Canada, pp. 1051-1087 in Geodiversitas 44 (33) on page 1075, DOI: 10.5252/geodiversitas2022v44a33, http://zenodo.org/record/7477657, {"references":["BILLINGS E. 1872. - On some fossils from the primordial rocks of Newfoundland. Canadian Naturalist and Quarterly Journal of Science 6: 465 - 479. https: // doi. org / 10.5962 / bhl. title. 38279","HUTCHINSON R. D. 1962. - Cambrian stratigraphy and trilobite faunas of southeastern Newfoundland. Geological Survey of Canada Bulletin 88 (1): 1 - 156. https: // doi. org / 10.4095 / 123902","MARTIN F. & DEAN W. T. 1988. - Middle and upper Cambrian acritarch and trilobite zonation at Manuels River and Random Island, eastern Newfoundland. Geological Survey of Canada Bulletin 381 (1): 1 - 91.","WHITTINGTON H. B., CHATTERTON B. D. E., SPEYER S. E., FORTEY R. A., OWENS R. M., CHANG W. T., DEAN W. T., JELL P. A., LAURIE J. R., PALMER A. R., REPINA L. N., RUSHTON A. W. A., SHERGOLD J. H., CLARKSON E. N. K., WILMONT N. V. & KELLY S. R. A., 1997. - Treatise on Invertebrate Paleontology, Part O, Arthropoda 1, Trilobita, Revised. Geological Society of America and University of Kansas, Boulder, Colorado, and Lawrence, Kansas, 530 p.","FLETCHER T. P. 2006. - Bedrock Geology of the Cape St. Mary's Peninsula, Southwest Avalon Peninsula, Newfoundland (includes parts of Nts map sheets 1 M / 1, 1 N / 4, 1 L / 16 and 1 K 13). Report, 06 - 02. Government of Newfoundland and Labrador, Geological Survey, Department of Natural Resources, St. John's, 117 p.","HICKS H. 1872. - On some undescribed fossils from the Menevian Group. The Quarterly Journal of the Geological Society of London 28 (1): 173 - 185. https: // doi. org / 10.1144 / gsl. jgs. 1872.028.01 - 02.17","COOK A. F. 1997. - Temporary exposure of the Middle Cambrian, Warwickshire, England. Geological Magazine 114 (1): 33 - 40. https: // doi. org / 10.1017 / s 0016756800043405"]}

Genus Clarella Howell, 1933 Clarella Howell, 1933: 219. — Type species: Anapolenus venustus Billings, 1872, designated as lectotype by Howell (1933). DIAGNOSIS. — Glabella with great forward expansion anterior of S1; palpebral lobes slightly sigmoidal, reaching almost genal angle; thorax with 15 segments; pygidium without border, up to four pairs of marginal spines; short axis with one to two axial rings (based on Howell 1933; Whittington et al. 1997, with modifications). REMARKS Clarella is distinguished from Anapolenus Salter, 1864a by sigmoidally shaped palpebral lobes that almost reach the genal angle. The palpebral lobes of Anapolenus curve in a uniform arc, reaching the genal angle. The pygidium of Clarella lacks a border, while that of Anapolenus is bordered (Howell 1933; Whittington et al. 1997)., Published as part of Unger, Tanja, Hildenbrand, Anne, Stinnesbeck, Wolfgang & Austermann, Gregor, 2022, Biostratigraphy and taxonomy of polymerid trilobites of the Manuels River Formation (Drumian, middle Cambrian), Newfoundland, Canada, pp. 1051-1087 in Geodiversitas 44 (33) on page 1075, DOI: 10.5252/geodiversitas2022v44a33, http://zenodo.org/record/7477657, {"references":["HOWELL B. F. 1933. - The classification of the trilobite Subfamily, Centropleurinae. Meddelelser fra Dansk Geologisk Forening 8 (3): 215 - 219.","BILLINGS E. 1872. - On some fossils from the primordial rocks of Newfoundland. Canadian Naturalist and Quarterly Journal of Science 6: 465 - 479. https: // doi. org / 10.5962 / bhl. title. 38279","WHITTINGTON H. B., CHATTERTON B. D. E., SPEYER S. E., FORTEY R. A., OWENS R. M., CHANG W. T., DEAN W. T., JELL P. A., LAURIE J. R., PALMER A. R., REPINA L. N., RUSHTON A. W. A., SHERGOLD J. H., CLARKSON E. N. K., WILMONT N. V. & KELLY S. R. A., 1997. - Treatise on Invertebrate Paleontology, Part O, Arthropoda 1, Trilobita, Revised. Geological Society of America and University of Kansas, Boulder, Colorado, and Lawrence, Kansas, 530 p.","SALTER J. W. 1864 a. - On some new fossils from the Lingula-flags of Wales. The Quarterly Journal of the Geological Society 20: 233 - 241. https: // doi. org / 10.1144 / gsl. jgs. 1864.020.01 - 02.33"]}