Schizophoria King, 1850

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 : 898-899

Subgenus Schizophoria King, 1850

Type species: Conchyliolithus Anomites (resupinatus) Martin, 1809, from the Visean of Derbyshire, England .

Remarks.— Schizophoria contains a large number of species from all over the World, with great morphological variability. Lazarev (1976) established two subgenera: Paraschizophoria and Pockockia but, as indicated by Harper (2000), the use of Lazarev’s subgenera in the literature is restricted.

Schizophoria is distinguished from Aulacophoria Schuchert and Cooper, 1931 , from the Mississippian of Europe as this has a planoconvex profile, with a catacline ventral interarea.

Schizophoria (Schizophoria) resupinata ( Martin, 1809)

Fig. 13L–O .

1809 Conchyliolithus Anomites (resupinatus); Martin 1809: pl. 49: 13. 1862 Orthis resupinata ( Martin, 1809) var. connivens Phillips, 1836 ;

Davidson 1862 a: 131, pl. 29: 6,7; pl. 30: 1–5. non 1862 Orthis resupinata Martin, 1809 ; Davidson 1862 a: 130, pl. 29:

1–3; pl. 30: 1–5. non 1862 Orthis resupinata Martin, 1809 var. gibbera Portlock, 1843 ;

Davidson 1862 a: 130, pl. 29: 5.

1965 Schizophoria resupinata ( Martin, 1809) ; Wright 1965: H332, fig. 210: 5a–b.

1968 Schizophoria resupinata ( Martin, 1809) ; Pocock 1968: 80, text-figs. 13–15, pl. 18: 7a–b. (cum syn.)

1991 Schizophoria resupinata ( Martin, 1809) ; Brunton and Tilsley 1991: 289.

2000 Schizophoria (Schizophoria) resupinata ( Martin, 1809) ; Harper 2000: fig. 612: a–b.

2000 Schizophoria (Schizophoria) resupinata ( Martin, 1809) lata Stainbrook, 1940; Harper 2000: fig. 612: c–f.

2006 Schizophoria resupinata ( Martin, 1809) ; Bassett and Bryant 2006: 504, pl. 6: 1–10; pl. 7: 1–16; text-figs. 6, 7.

non 2007 Schizophoria resupinata ( Martin, 1809) ; Butts 2007: 55: 5.3–5.10.

2010 Schizophoria resupinata ( Martin, 1809) ; Mottequin 2010: 259, pl. 2: 12–13; text-fig. 13.

2011 Schizophoria (Schizophoria) resupinata ( Martin, 1809) ; Bahrammanesh et al. 2011: fig. 7: f–g.

?2014 Schizophoria resupinata ( Martin, 1809) ; Ibaraki et al. 2014: 73, figs. 4.1, 4.2. (cum syn.)

2016 Schizophoria resupinata ( Martin, 1809) ; Denayer et al. 2016: fig. 7M.

?2016 Schizophoria resupinata ( Martin, 1809) ; Tazawa et al. 2016: 57: figs. 6.1, 6.2. (cum syn.)

2017 Schizophoria (Schizophoria) resupinata ( Martin, 1809) ; Qiao et al. 2017: fig. 5e.

?2019 Schizophoria pinguis Demanet, 1934 ; Tazawa and Kurita 2019: 222, fig. 4b–c. (cum syn.)

Material.—Three articulated specimens: MPUM 11999 ( RCC 1B-26); MPUM 12000 ( RCC 1B-3; RCC 60-1b). One ventral valves: MPUM 12002 ( RCC 1B-20a). Six dorsal valves: MPUM 12003 ( RCC 1B-4); MPUM 12004 ( RCC 1B-25); MPUM 12005 ( RCC 36-1a); MPUM 12006 ( RCC 10-35a; RCC 108-2; RCC 110-1a). One unidentified valve: MPUM 12007 ( RCC 110-3a). Twenty-seven fragments: MPUM 12008 ( RCC 1-3, 34b; RCC 1B-2, 6, 8, 10, 11, 12a, 14, 17, 21, 24a, 27c, 27d, 28, 29; RCC 32-8b; RCC 36-2, 4, 5; RCC 41-12; RCC 42-31, 33; RCC 60-18b; RCC 128-14, 21; RCK 15-60b). All from mud mound complex of Ricklow Quarry, Monyash, Derbyshire, UK, Monsal Dale Limestone Formation, Brigantian, upper Visean.

Description.—Medium-sized, dorsibiconvex shell with transversely oval outline; cardinal margin straight, reaching more than two-thirds of maximum width, which is attained at one-third shell length. Anterior commissure rectimarginate. Ventral valve gently convex to slightly concave anteriorly. Ventral umbo straight. Interarea low, apsacline. Dorsal valve regularly convex. Dorsal umbo slightly curved. Shallow, flat sulcus may develop near the umbo, increasing in width, but becoming obsolete anteriorly.

Entire surface of both valves multicostellate. Ribs start at umbo, unless for rare intercalating costellae. Ribs rounded, very low, with narrow interspaces. Ribs number 3–4 per 1.0 mm, 22.0 mm from the umbo.

Remarks.—The specimens are assigned to Schizophoria (Schizophoria) resupinata because their morphology, size and ornamentation are comprised in the variability of the species as it was re-described by Pocock (1968), based on Mississippian specimens from Belgium, Great Britain, and Ireland. They also match the description for S. (S.) resupinata given by Bassett and Bryant (2006) and Bahrammanesh et al. (2011).

The specimens differ from S. connivens ( Phillips, 1836) by being larger, by lacking a quadrate–uniplicate anterior commissure and by having a finer multicostellate ornamentation; from S. gibbera by lacking a high, rounded anterior uniplication; from S. woodi Bond, 1941 , by lacking a narrow angular ventral sulcus and from S. linguata Quenstedt, 1871 , and S. annectans Pocock, 1968 , in being larger, in having a coarser multicostellate ornamentation and a rectimarginate commissure.

Stratigraphic and geographic range.— Schizophoria (Schizophoria) resupinata is recorded in the uppermost Famennian–Pennsylvanian of Great Britain and Ireland (e.g., Davidson 1862 a; Parkinson 1954a; Wolfenden 1958; Brunton 1968; Mitchell 1971; Bassett and Bryant 2006; this study), Belgium (e.g., Pocock 1968), Germany ( Winkler-Prins and Amler 2006), the Donets and Moscow basins in Ukraine and western Russia (e.g., Sarycheva and Sokolskaya 1952), Siberia (Kuznetsk Basin; e.g., Sarycheva et al. 1963), north Iran (Mobarak Formation; Bahrammanesh et al. 2011), Kazakhstan, Kirghizistan and China (e.g., Sun and Baliński 2008). It is abundant in the Visean of Eurasia ( Pocock 1968).

Schizophoria (Schizophoria) cf. connivens ( Phillips, 1836)

Fig. 13J, K .

Material.—One articulated specimen: MPUM 12009 ( RCC 60-48). One dorsal valve: MPUM 12010 ( RCC 1B-7). Both from mud mound complex of Ricklow Quarry, Monyash, Derbyshire, UK, Monsal Dale Limestone Formation, Brigantian, upper Visean.

Remarks.—The specimens are a poorly convex valve and a fragment of the anterior part of an articulated specimen with a transverse oval outline and an inequibiconvex profile. Both specimens are covered by prominent cylindrical ribs with narrow interspaces, increasing in number anteriorly by intercalation. Ribs number 3 per 1.0 mm at the anterior commissure. Regularly concentric lamellae are developed, having a width of 2.0 mm.

The specimens differ from S. resupinata by having a more prominent ribbing, thus they are tentatively assigned to S. connivens , from the Mississippian of Yorkshire, which is small and characterised by prominent ribbing and concentric lamellae ( Pocock 1968).

Order Rhynchonellida Kuhn, 1949

Superfamily Pugnacoidea Rzhonsnitskaia, 1956

Family Pugnacidae Rzhonsnitskaia, 1956

Genus Pleuropugnoides Ferguson, 1966

Type species: Terebratula pleurodon Phillips, 1836 , from the lower Visean of England .

Remarks.— Savage et al. (2002) described Pleuropugnoides as having fold and sulcus starting at the umbones. However, it is evident from the published photographs ( Savage et al. 2002: fig. 800: 1a–k) that in fact the fold and sulcus start from the mid-length.

The genus differs from Pugnoides Weller, 1910 , Propriopugnus Brunton, 1984 , and Pugnax Hall and Clarke, 1893 , by the more pronounced ornamentation of costae covering the entire surface of both valves.

Figures

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.