Pugilis cf. scotica (Sowerby, 1814)

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 : 891

Pugilis cf. scotica (Sowerby, 1814)

Fig. 11L .

Material.—One articulated specimen: MPUM11958 (RCC2-41) from mud mound complex of Ricklow Quarry, Monyash, Derbyshire, UK, Monsal Dale Limestone Formation, Brigantian, upper Visean.

Description.—Medium-sized, elongated concavo-convex shell with suboval outline. Cardinal margin wide, corresponding to maximum width. Both valves geniculated. Anterior commissure uniplicate. Ventral valve enrolled, visceral disc convex; geniculation angle 120°. Trail long, tubiform, straight. Low, rounded ventral sulcus, starting posteriorly to geniculation and extending on trail.

Ornamentation consists of subrounded ribs, with narrow interspaces on visceral discs, becoming fainter, thread like, with wide interspaces on trail. Ribs increase in number anteriorly by bifurcation. They number 16 per 10.0 mm at geniculation.

Remarks. — The specimen is close in its morphology and ornamentation to the specimens assigned to Pugilis cf. kilbridensis from the mud mound complex in Ricklow Quarry, but differs in having a less enrolled ventral valve, wider angle of geniculation and shallow ventral sulcus. These characters make it closer to Pugilis scotica , from the Asbian– Brigantian of England and Scotland ( Muir-Wood 1928).

Figures

Fig. 11. Productidae from the Brigantian (uppermost Visean) of Ricklow Quarry, near Monyash, Derbyshire, UK (localities RCC-, RCK-; Fig. 3). A–F. Antiquatonia insculpta (Muir-Wood, 1928). A. MPUM11938 (RCC1B-9) in anterior (A1) and lateral (A2) views. B. MPUM11939 (RCC3-15a) in antero-ventral view. C. MPUM11940 (RCC42-26) in antero-ventral view. D. MPUM11941 (RCC110-1b) in lateral view. E. MPUM11944 (RCC2-25) ventral valve in ventral view. F. MPUM11947 (RCC128-2) dorsal valve interior and external cast. G, H. Dictyoclostus pinguis (Muir-Wood, 1928). G. MPUM11950 (RCC54-11) ventral valve in ventral view. H. MPUM11951 (RCK15-63a) dorsal valve external cast. I–K. Pugilis cf. kilbridensis (Muir-Wood, 1928). I. MPUM11956 (RCC128-3) dorsal valve interior and external cast. J. MPUM11955 (RCC54-4) ventral valve in anterior (J1) and lateral (J2) views. K. MPUM11954 (RCC2-47) ventral valve in anterior view. L. Pugilis cf. scotica (Sowerby, 1814), MPUM11958 (RCC2-41) in lateral (L1), ventral (L2), and anterior (L3) views. M, N. Buxtonia scabricula (Sowerby, 1814). M. MPUM11959 (RCC1B-13) in ventral view. N. MPUM11960 (RCC35A-11a) in ventral view.