Limbifera sp.

Carniti, Alessandro P., Porta, Giovanna Della, Banks, Vanessa J., Stephenson, Michael H. & Angiolini, Lucia, 2022, Brachiopod fauna from uppermost Visean (Mississippian) mud mounds in Derbyshire, UK, Acta Palaeontologica Polonica 67 (4), pp. 865-915 : 886

Limbifera sp.

Fig. 9M .

Material.—One ventral valve: MPUM11890 (RCC54-10b) from mud mound complex of Ricklow Quarry, Monyash, Derbyshire, UK, Monsal Dale Limestone Formation, Brigantian, upper Visean.

Description.—Small, transversely subrectangular ventral valve. Anterior commissure rectimarginate. Ventral visceral disc flat; geniculation angle about 100°. Very shallow sulcus.

Ornamentation consists of low, subrounded, bifurcating ribs with narrow interspaces, starting from umbo. They number 6–7 per 5.0 mm, 10.0 mm from the umbo. Subrounded rugae, 7–8 in 5.0 mm on ventral visceral disc, resulting in reticulate ornamentation.

Remarks.—The specimen is similar in the outline and ornamentation to Limbifera griffithiana from the upper Mississippian of England and Belgium, figured by Muir-Wood (1928: pl. 3: 1–3) and Brunton and Mundy (1988: figs. 5, 8.1–22, 9.1–7). However, the gutter anteriorly is not preserved, and it has stronger costae and a less evident concentric ornamentation.

Figures

Fig. 9. Productellidae and Productidae from the Brigantian (uppermost Visean) of Ricklow Quarry, near Monyash, Derbyshire, UK (localities RCC-, RCK-; see Fig. 3). A–E. Krotovia spinulosa (Sowerby, 1814). A. MPUM11886 (RCC73-22a) in ventral view. B. MPUM11889 (RCC3-18) dorsal valve interior and external cast. C. MPUM11891 (RCK15-16) interior and external cast. D. MPUM11892 (RCK15-28) dorsal valve interior and external cast. E. MPUM11887 (RCK15-10) in ventral view. F–K. Breileenia radiata Brunton in Brunton and Lazarev, 1997. F. MPUM11895 (RCC65-1) in anterior (F1), ventral (F2), and lateral (F3) views. G. MPUM11898 (RCC12-1) dorsal valve external cast. H. MPUM11899 (RCC12-7) dorsal valve interior and external cast. I. MPUM11900 (RCC12-15) dorsal valve external cast. J. MPUM11903 (RCC38A-2) fragment in anterior view. K. MPUM11901 (RCC12-23b) dorsal valve external cast. L. Geniculifera keyserlingiana (De Koninck, 1843), MPUM11905 (RCC73-28) in antero-ventral (L1), lateral (L2), and dorsal (L3) views. M. Limbifera sp., MPUM11890 (RCC54-10b), ventral valve in ventral view. N. Carringtonia cf. carringtoniana (Davidson, 1862a), MPUM11906 (RCC2-51) dorsal valve interior and external cast. O. Productus sp., MPUM11908 (RCC1-61b) in ventral view. P. Productus sp., MPUM11909 (RCC60-6) dorsal valve external cast.