Buxtoniini, Muir-Wood and Cooper, 1960

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 : 894

Buxtoniini gen. et sp. indet.

Fig. 12F .

Material.—Two dorsal valves: MPUM11971 (RCK15B-1a); MPUM11972 (RCC48-42). One fragment: MPUM11973 RCC48-2a). All from mud mound complex of Ricklow Quarry, Monyash, Derbyshire, UK, Monsal Dale Limestone Formation, Brigantian, upper Visean.

Remarks.—The specimens are poorly preserved dorsal valves with flat visceral discs and convex geniculation (geniculation angle 90°). They show a low, rounded fold starting from the umbo and an ornamentation of subangular rugae three per 5.0 mm length) bearing irregular rows of elongated dimples (1.0 mm long; five per 5 mm 2). Faint ribs with wide interspaces on trail, four per 5.0 mm. The specimens are attributed to the Buxtoniini based on their ornamentation of dense elongated dimples and irregular ribs anteriorly.

Figures

Fig. 12. Productidae and Echinoconchidae from the Brigantian (uppermost Visean) of Ricklow Quarry, near Monyash (localities RCC-, RCK-; see Fig. 3) and Wensley Dale, near Matlock (locality WI1; Fig. 2), Derbyshire, UK. A–C. Buxtonia scabricula (Sowerby, 1814). A. MPUM11963 (WI-40) in ventral view. B. MPUM11962 (WI1-38) in ventral (B1), dorsal (B2), and lateral (B3) views. C. MPUM11961 (WI1-14) in ventral (C1), dorsal (C2), and posterior (C3) views. D, E. Buxtonia sp. D. MPUM11968 (RCC8-2a) ventral valve in lateral (D1) and ventral (D2) views. E. MPUM11969 (WI1-2) ventral valve in ventral view. F. Buxtoniini gen. et sp. indet., MPUM11971 (RCK15B-1a) dorsal valve external cast. G–K. Echinoconchus punctatus (Sowerby, 1822). G. MPUM11983 (RCC1B-18) dorsal valve external cast. H. MPUM11980 (RCC54-7) ventral valve in ventral view. I. MPUM11975 (RCK15-21) in ventral view. J. MPUM11974 (RCC72-1) in ventral view. K. MPUM11977 (WI1-28) in lateral (K1), ventral (K2), dorsal (K3), and anterior (K4) views.