Echinoconchus punctatus (Sowerby, 1822)

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

Echinoconchus punctatus (Sowerby, 1822)

Figs. 12G–K , 13A .

1809 Conchyliolithus Anomites ( punctatus ); Martin 1809: pl. 37: 6, non 7–8.

1822 Productus punctatus ; Sowerby 1822: pl. 323: right and lower figure,?left hand lower figure.

1844 Producta punctata Sowerby, 1822 ; M’Coy 1844: 113 (pars).

1862 Productus punctatus Sowerby, 1822 ; Davidson 1862 a: 172 (pars), pl. 44: 9, 11, 16, 17. (cum syn.)

1914 Pustula punctata (Sowerby, 1822) ; Thomas 1914: 303, pl. 17: 16–19; text-fig. 11.

1951 Echinoconchus punctatus (Sowerby, 1822) ; Muir-Wood 1951: 102, pl. 4: 2.

1952 Echinoconchus punctatus (Sowery, 1822) ; Sarycheva and Sokolskaya 1952: 99, pl. 18: 120.

1960 Echinoconchus punctatus (Sowerby, 1822) ; Muir-Wood and Cooper 1960: pl. 66: 1–2; pl. 82: 8–10; pl. 83: 1–4; pl. 88: 11; pl. 125: 5.

1965 Echinoconchus punctatus (Sowerby, 1822) ; Muir-Wood 1965: fig. 353: 1a–d.

1971 Echinoconchus punctatus (Sowerby, 1822) ; Mitchell 1971: pl. 14: 3.

1991 Echinoconchus punctatus (Sowerby, 1822) ; Brunton and Tilsley 1991: 291.

2000 Echinoconchus punctatus (Sowerby, 1822) ; Brunton et al. 2000: fig. 349: a–e.

2016 Echinoconchus punctatus (Sowerby, 1822) ; Denayer et al. 2016: fig. 7: H–K.

2017 Echinoconchus punctatus (Sowerby, 1822) ; Tazawa 2017: 335, figs. 6.6, 6.7. (cum syn.)

Material.—Nine articulated specimen: MPUM 11974 ( RCC 72-1); MPUM 11975 ( RCK 15-21); MPUM 11976 ( RCK 15-47); MPUM 11978 ( RCC 1B-1); MPUM 11977 (WI1-28); MPUM 11979 (WI1-22, 23, 29, 35). Seven ventral valves: MPUM 11980 ( RCC 54-7); MPUM 11981 ( RCC 1-24; RCC 2- 14a; RCC 40-9; RCC 48-12; RCC 85-1a); MPUM 11982 (WI1-7). Eight dorsal valves: MPUM 11983 ( RCC 1B-18); MPUM 11984 ( RCC 1B-15; RCC 8-7; RCC 12-13e; RCC 13-3d; RCC 68-1; RCK 15-1c); MPUM 11985 (WI1-12b). Nineteen fragments: MPUM 11986 ( RCC 1-27a, 40a, 47, 61a, 61c; RCC 10-39a; RCC 12-11a, 13a; RCC 12BIT-1; RCC 40-4b; RCC 41-17a; RCC 54-1, 2, 10c, 13, 17d, 17e; RCK 15-45; RCK 16-2). All from mud mound complex of Ricklow Quarry, Monyash, Derbyshire, UK, Monsal Dale Limestone Formation, Brigantian (RCC-, RCK-), and Wensley Dale, Matlock, Derbyshire, UK, Eyam Limestone Formation, upper Brigantian, upper Visean (WI1).

Description.—Medium-sized, concavo-convex shell with suboval outline; cardinal margin wide, maximum width attained at shell mid-length. Ears small, flat. Rounded cardinal extremities. Corpus cavity deep. Anterior commissure uniplicate. Ventral valve poorly convex posteriorly, not geniculated. Shallow, rounded sulcus starting 10.0 mm from the umbo. Dorsal valve flat to concave anteriorly, not geniculated. Low, rounded fold starting 7.0–8.0 mm from the umbo.

Both valves covered by subangular rugae, 4–6 per 10.0 mm length, separated by broadly rounded interspaces, narrower on flanks. Each one bears one row of large spines posteriorly, then another row of spines, equal or smaller in diameter, and then 2–3 staggered rows of small spines, quincuncially arranged on the ruga crest. This pattern may vary considerably: some rugae may have only small quincuncially arranged spines, or only 1–2 rows of large spines, while wider rugae may be covered by quincuncially arranged large spines posteriorly with a narrower band of quincuncially arranged small spines anteriorly.

Cardinal process short-shafted, 2.0 mm long, bilobed.

Remarks.—The specimens are close in their morphology and ornamentation to Echinoconchus punctatus as described and figured by Thomas (1914), Muir-Wood and Cooper (1960) and Brunton (2000). They differ from E. defensus ( Thomas, 1914) in having a poorly convex ventral valve and an almost flat, rather than concave, dorsal valve, and from E. eximius ( Thomas, 1914) and E. subelegans ( Thomas, 1914) in having a fold-sulcus.

Stratigraphic and geographic range.— Echinoconchus punctatus is common in the Visean of Great Britain and Ireland ( Thomas 1914 and references therein; this study), the upper Tournaisian–upper Visean of Germany ( Winkler-Prins and Amler 2006), the upper Visean of Belgium (e.g., Denayer et al. 2016), the upper Visean of the Badajoz Province, and the Bashkirian of Cantabrian Mountains in Spain ( Winkler-Prins 1968; Martinez-Chacon 1979; Martinez-Chacon and Legrand-Blain 1992), the upper Visean of Poland ( Żakowa 1966), the Visean–Serpukhovian of Russia, Kazakhstan, Uzbekistan, and Kyrgyzstan (e.g., Sarycheva and Sokolskaya 1952; Tazawa 2017 and references therein), the upper Visean of northern China, and the South Kitakami Belt, Japan (e.g., Tazawa et al. 2016).

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.

Fig. 13. Echinoconchidae, Linoproductidae, Monticuliferidae, Orthotetida, and Orthida from the Brigantian (uppermost Visean) of Ricklow Quarry, near Monyash, Derbyshire, UK (localities RCC-, RCK-; see Fig. 3). A. Echinoconchus punctatus (Sowerby, 1822), MPUM11976 (RCK15-47) in ventral view. B–D. Pustula cf. pustulosa (Phillips, 1836), B. MPUM11989 (RCC128-17a) dorsal valve external cast. C. MPUM11987 (RCC41-1) in ventral view. D. MPUM11988 (RCC128-7) in ventral (D1) and dorsal (D2) views. E, F. Linoprotonia sp. E. MPUM11991 (RCC42-17) in ventral (E1) and lateral E2) views. F. MPUM11992 (RCC60-59) in ventral view. G. Fluctuaria undata (Defrance, 1826), MPUM11926 (RCC300-14) ventral valve in ventral view. H.?Serratocrista aff. dalriensis McIntosh, 1974, MPUM11997 (RCC10-40) ventral valve in ventral view. I. Schellwienella sp., MPUM11995 RCC36-12) ventral valve in ventral view. J, K. Schizophoria (Schizophoria) cf. connivens (Phillips, 1836). J. MPUM12009 (RCC60-48) in ventral view. K. MPUM12010 (RCC1B-7) dorsal valve in dorsal view. L–O. Schizophoria (Schizophoria.) resupinata (Martin, 1809). L. MPUM12003 (RCC1B-4) dorsal valve in dorsal view. M. MPUM11999 (RCC1B-26) in dorsal view. N. MPUM12004 (RCC1B-25) dorsal valve in dorsal view. O. MPUM12005 RCC36-1a) dorsal valve in dorsal view. Scale bars 10 mm.