External Subbetic Domain

In the easternmost Betic Range (Alicante and Murcia provinces, East Spain), representatives of Cirpa and Salgirella are recorded in Pliensbachian–lowermost Toarcian sediments from the epioceanic External Subbetic area (Baeza-Carratalá, Reference Baeza-Carratalá2013), which is characterized by pelagic seamount facies. Most of the taxa are recorded in the upper member of the Gavilán Formation (late Pliensbachian), which consists of red crinoidal grainstone beds with abundant glauconite, peloids, and intraclasts, with occasional calcarenite levels interspersed. Only the record of Cirpa briseis reaches up to the marly levels of the Zegrí Formation (uppermost Pliensbachian–lowermost Toarcian) (Fig. 1), which consists of thin beds of alternating yellowish and greenish marls and marly mudstone with sporadic calcarenites and yellowish sandy marlstone beds.

Figure 1. (1) Locations of the studied Pliensbachian–Lower Toarcian outcrops in the peri-Iberian platforms system, with wellerelloids among the constituents of the brachiopod assemblages. (2, 3) Synthetic Lower Jurassic stratigraphical sections showing the distribution of Wellerelloidea species in (2) the Betic Ranges and (3) the Lusitanian basin. Mir. = Mirabile Subzone; Spin. = Spinatum Zone.

Transitional External Betic Zones

Pliensbachian wellerelloids were also documented in the transitional areas of the Prebetic–Subbetic domains (La Mola region, Alicante, East Spain; Baeza-Carratalá et al., Reference Baeza-Carratalá, García Joral and Tent-Manclús2016b). This region is considered a linking area between shallow epicontinental platforms that prevailed in the Prebetic on the North and the Subbetic Domain characterized by pelagic seamount facies southwards. In this area, red crinoidal grainstone sediments, comparable to those of the External Subbetic area, characterize the upper Pliensbachian deposits (Baeza-Carratalá et al., Reference Baeza-Carratalá, García Joral and Tent-Manclús2016b).

Internal Subbetic Domain

This area is located in Sierra Gorda (Granada Province, South Spain). The wellerelloid-bearing deposits are represented by the intermediate and upper members of the Gavilán Formation (Sinemurian–earliest Pliensbachian in age). The intermediate member consists of a thick carbonate succession (Sandoval, Reference Sandoval1983; García-Hernández et al., Reference García-Hernández, Lupiani and Vera1986) characterized by micritic peloidal mudstone/packstone levels, sometimes with oolitic/oncolitic grainstone to packstone beds and algal wackestones containing large foraminifera, sponges, bivalves, gastropods, and echinoderms. The depositional setting was interpreted as shallow neritic platforms with occasional protected areas involving low- to middle-energy environments (Olóriz et al., Reference Olóriz, Linares, Goy, Sandoval, Caracuel, Rodríguez-Tovar, Tavera, Gibbons and Moreno2002; Ruiz-Ortiz et al., Reference Ruiz-Ortiz, Bosence, Rey, Nieto, Castro and Molina2004). Overlying these sediments, exposures of the upper member of Gavilán Formation, which are represented by crinoidal grainstone/packstone carbonates with crinoids, brachiopods, and bivalves, are interpreted as high-energy deposits in external-platform, tidal to intertidal areas, that accumulated during progressive drowning of the Early Jurassic platforms (Olóriz et al., Reference Olóriz, Linares, Goy, Sandoval, Caracuel, Rodríguez-Tovar, Tavera, Gibbons and Moreno2002).

Lusitanian Basin

Portuguese Cirpa are found mainly in Toarcian sediments from the Rabaçal-Condeixa region and the Peniche area (Lusitanian Basin). They are recorded in Rabaçal in the basal deposits of the São Gião Formation (Comas-Rengifo et al., Reference Comas-Rengifo, Duarte, García Joral and Goy2013; Piazza et al., Reference Piazza, Duarte, Renaudie and Aberhan2019) as whitish gray marly beds (Fig. 1). In Peniche, Cirpa occurs in the lower member of the Cabo Carvoeiro Formation (Alméras, Reference Alméras, Copper and Jin1996; Comas-Rengifo et al., Reference Comas-Rengifo, Duarte, Félix, García Joral, Goy and Rocha2015), which consists of predominantly bioturbated and ferruginous gray marls with a few intercalations of cm-thick marly limestones. Both formations correspond to a low-energy, distal homoclinal ramp, deeper to the west/northwest, typified by hemipelagic sequences and facies rich in organic matter, where an alternation of marlstone and argillaceous limestone beds prevailed (Duarte, Reference Duarte2007).

Asturian Basin

The only wellerelloid documented in the Asturian Basin is the pervasive Cirpa briseis (Comas-Rengifo and Goy, Reference Comas-Rengifo and Goy2010) in deposits of the Rodiles Formation (Pliensbachian, Davoei–Margaritatus chronozones). The Rodiles Formation consists of a rhythmically alternating succession of marls and micritic and marly limestone beds, typifying a depositional environment consisting in an open sea carbonate ramp (Valenzuela et al., Reference Valenzuela, García-Ramos and Suárez de Centi1986). Cirpa briseis probably reached this basin in the transgressive maximum that occurred in the early-late Pliensbachian transition (Comas-Rengifo and Goy, Reference Comas-Rengifo and Goy2010).

Type species

Rhynchonella (Cirpa) primitiva De Gregorio, Reference De Gregorio1930

Cirpa briseis (Gemmellaro, Reference Gemmellaro1874)
Figure 3.15–3.28

Reference Gemmellaro1874

Rhynchonella briseis Gemmellaro, p. 97, pl. 11, figs. 19–22.

Reference Haas1884

Rhynchonella briseis Gemmellaro; Haas, p. 4. pl. 1, figs. 3–5 (non fig. 6).

Reference Parona1884

Rhynchonella briseis Gemmellaro; Parona, p. 244, pl. 3, fig. 1 (part; ? pl. 2, figs. 10–20; ? pl. 3, fig 2).

Reference Geyer1889

Rhynchonella variabilis Schlotheim; Geyer, p. 36, pl. 4, figs. 19–21.

Reference Di Stefano1891

Rhynchonella briseis Gemmellaro; Di Stefano, p. 208, pl. 3, figs. 9–13 (part; not var. iphimedia, pl. 3, figs. 14–17).

Reference Parona1892

Rhynchonella briseis Gemmellaro; Parona, p. 29, pl. 2, fig. 1 (part; not pl. 2, figs. 2–7).

Reference Böse1897

Rhynchonella briseis Gemmellaro; Böse, p. 184, pl. 13, fig. 20.

Reference Böse and Schlosser1900

Rhynchonella variabilis Schlotheim; Böse and Schlosser, p. 196, pl. 18, figs. 7, 8.

?Reference Böse and Schlosser1900

Rhynchonella aff. alberti Oppel; Böse and Schlosser, p. 193, pl. 18, fig. 1.

Reference Principi1910

Rhynchonella briseis Gemmellaro; Principi, p. 78, pl. 3, fig. 3.

?Reference Dareste de la Chavanne1920

Rhynchonella briseis Gemmellaro; Dareste de la Chavanne, p. 15, pl. 1, fig. 3; pl. 3, fig. 2.

Reference Ager1958

Cirpa briseis (Gemmellaro); Ager, p. 52, text-fig. 28.

Reference Sacchi Vialli and Cantaluppi1967

Cirpa fronto briseis Sacchi Vialli and Cantaluppi, p. 73, pl. 11, figs. 1–3.

?Reference Sacchi Vialli and Cantaluppi1967

Prionorhynchia aff. latifrons (Stur); Sacchi Vialli and Cantaluppi, p. 77, pl. 12, fig. 1.

Reference Benigni1978

Cirpa briseis (Gemmellaro); Benigni, p. 139, pl. 14, fig. 1.

Reference Giovannoni1981

Cirpa briseis (Gemmellaro); Giovannoni, p. 207, pl. 2, figs. 4–6.

Reference Alméras and Elmi1987

Cirpa briseis (Gemmellaro); Alméras and Elmi, p. 50, pl. 3, fig. 1.

Reference Alméras and Elmi1987

Cirpa briseis (Gemmellaro) morpho langi Alméras and Elmi, p. 50, pl. 3, figs. 2–5.

?Reference Manceñido, Pálfy and Vörös1993

Cirpa cf. briseis (Gemmellaro); Manceñido, p. 83, pl. 1, fig. 6.

Reference Iñesta1999

Cirpa briseis (Gemmellaro); Iñesta, p. 15, pl. 1, fig. 6.

?Reference Alméras and Fauré2000

Cirpa briseis (Gemmellaro); Alméras and Fauré, p. 104, pl. 11, figs. 7–10.

Reference Manceñido2002

Cirpa briseis (Gemmellaro); Manceñido et al., p. 1264, fig. 861 (1).

Reference Vörös, Szabó, Dulai, Szente, Ebli and Lobitzer2003

Cirpa briseis (Gemmellaro); Vörös et al., p. 70, pl. 6, figs. 13–15.

Reference Vörös, Szabó, Dulai, Szente, Ebli and Lobitzer2003

Cirpa cf. briseis (Gemmellaro); Vörös et al., p. 78, pl. 8, figs. 18, 19.

Reference Baeza-Carratalá2004

Cirpa briseis (Gemmellaro); Baeza-Carratalá, p. 211, fig. 2(1).

?Reference Alméras, Elmi and Fauré2007

Cirpa briseis (Gemmellaro); Alméras et al., p. 46.

Reference Baeza-Carratalá2008

Cirpa briseis (Gemmellaro); Baeza-Carratalá., p. 154, pl. 4, figs. 5–9.

Reference Mandl, Dulai, Schlögl, Siblík, Szabó, Szente and Vörös2010

Cirpa briseis (Gemmellaro); Mandl et al., p. 92, pl. 2, fig. 1; pl. 7, fig. 1.

Reference Comas-Rengifo and Goy2010

Cirpa briseis (Gemmellaro); Comas-Rengifo and Goy, p. 12, pl. 1, figs. 10, 11.

?Reference Vörös and Kandemir2011

Cirpa cf. briseis (Gemmellaro); Vörös and Kandemir, p. 353, fig. 4 (3).

non Reference Rodrigo2011

Cirpa cf. briseis (Gemmellaro); Rodrigo, p. 78, pl. 1, figs. 2, 3.

Reference Alméras and Cougnon2013

Cirpa briseis (Gemmellaro); Alméras and Cougnon, p. 55, pl. 5, fig. 10.

Reference Alméras and Fauré2013

Cirpa briseis (Gemmellaro); Alméras and Fauré, p. 32, pl. 1, fig. 8.

Reference Baeza-Carratalá2013

Cirpa briseis (Gemmellaro); Baeza-Carratalá., p. 84, fig. 5 (4).

Reference Alméras, Cougnon, Guibbert and Fauré2014

Cirpa briseis (Gemmellaro); Alméras et al., p. 20, pl. 2, fig. 2.

Reference Alméras, Cougnon, Guibbert and Fauré?2014

Cirpa briseis (Gemmellaro); Alméras et al., p. 20, pl. 2, fig. 3.

Reference Baeza-Carratalá, García Joral and Tent-Manclús2016b

Cirpa briseis (Gemmellaro); Baeza-Carratalá et al., p. 248, fig. 4 (1).

Figure 3. Some representative Pliensbachian species of Cirpa from the External Subbetic paleomargin. Each specimen is ordered consecutively in dorsal, anterior, and lateral views. (1–14) Cirpa lucentina n. sp. (1–3) Holotype, specimen CCA.8.Clat.1 from Cerro de La Cruz; (4–6) specimen O.5.B.12.4 from JdC collection; (7–9) specimen I.11.T19(19).1 from Sierra de Algayat; (10–12) specimen CCA.8.Clat.2 from Cerro de La Cruz; (13, 14) specimen I.11.T9(9).2 from Sierra de Algayat. (15–28) Cirpa briseis (Gemmellaro, Reference Gemmellaro1874). (15–17) Specimen CCA.8.Cbri.1 from Cerro de La Cruz; (18–20) specimen I.12.24.2 from Sierra de Algayat; (21, 22) specimen O.8.23.T1.5 from Sierra de la Espada; (23–25) specimen I.12.3.2 from Sierra de Algayat; (26–28) specimen I.13.B5.5 from Sierra de Algayat. (29–37) Cirpa planifrons (Ormós, Reference Ormós1937). (29–31) Specimen CCA.8.C.pla.1 from Cerro de La Cruz; (32–34) specimen CCA.8.C.pla.2 from Cerro de La Cruz; (35–37) specimen Z1B.Clat.1 from Sierra de Orts. Scale bar = 1 cm.

Holotype

The original type material, deposited in the collections of the University of Palermo, was described by Gemmellaro (Reference Gemmellaro1874, pl. 11, figs. 19–22) from the Pliensbachian of Sicily (“Terebratula Aspasia beds”).

Occurrence

As can be deduced from the synonymy, C. briseis is pervasive and widespread from Pontides to Algeria throughout different Tethyan biochoremas. Early records of this species were cited in the “Middle Lias” from the Italian basins, the pre-Alps, Greece, and the Sinemurian–Pliensbachian of Schafberg (Austria), among many other records. The occurrence of this taxon is remarkable in the Domerian (Margaritatus Zone, Stokesi Subzone) from the Pyrenees; the late Domerian (Spinatum Zone) from the French Alps; Pliensbachian (Margaritatus Zone) from Quercy (Alméras and Fauré, Reference Alméras and Fauré2013) and Pliensbachian (Spinatum Zone) from the SE French Central Massif (Alméras and Elmi, Reference Alméras and Elmi1987); and the latest Pliensbachian from Eastern Pontides (Vörös and Kandemir, Reference Vörös and Kandemir2011). In the peri-Iberian platform system, it is recorded in the late Pliensbachian from the Subbetic area (Azéma, Reference Azéma1977; Iñesta, Reference Iñesta1988; Baeza-Carratalá, Reference Baeza-Carratalá2013); late Pliensbachian from the Prebetic/Subbetic transition (Baeza-Carratalá et al., Reference Baeza-Carratalá, García Joral and Tent-Manclús2016b), and in the Davoei–Margaritatus chronozones (Pliensbachian) from the Asturian basin (Comas-Rengifo and Goy, Reference Comas-Rengifo and Goy2010).

Description

Medium-sized dorsibiconvex shell, usually wider than long, with the maximum width and thickness shifted toward the anterior third of the shell. Dorsal outline is triangular to subpentagonal, with a rounded anterior margin. The beak is strong, suberect, and shows a small pedicle foramen and poorly developed beak ridges. The flanks of the shell show shallow and relatively narrow planareas. Lateral commissure is slightly arcuate near the beak, then running straight to the anterior margin, tilted with ventral orientation. Anterior commissure is uniplicate with a marked subtrapezoidal dorsal median fold, occasionally rendering a subcynocephalous profile to the shell. Ribbing pattern consists of 7–12 sharp and spaced ribs (3–4 of which are present on the median fold), triangular in cross-section, running along the entire shell length without bifurcation.

The internal structure of this species (Fig. 4) shows a subrectangular delthyrial cavity in cross-section, where a strong pedicle collar is visible and the double deltidial plates, distinctive of several taxa arranged into the genus Cirpa, are present (Fig. 4). Dental plates are ventrally convergent to subparallel. Hinge teeth are massive and crenulated, and are inserted in rather deep and crenulated sockets. The dorsal median septum is very short with no detectable evidence of a septalium. Hinge plates fused in the early stages (Fig. 4), ventrally arcuate to horizontal. Crural development is incipiently hamiform, but with a particularly short dorso-ventral expansion. Thus, initially, the crural bases show a markedly triangular cross-section with bracket-shaped crural progress and endings, reaching the total crural architecture around one-third of the shell-length. Secondary layer of the shell shows an eurinoid pattern, with rhombic to subrectangular cross-section of coarse calcite fibers ~70–80 μm wide and 30 μm thick (Fig. 5.3).

Figure 4. Internal structure of Cirpa briseis (Gemmellaro, Reference Gemmellaro1874) from the Pliensbachian (Eastern Prebetic); serial sections orientated with the ventral valve up. (1) Specimen CCC-3 in which serial sections were performed; (2) transverse serial sections through the same specimen (distance from the apex in mm); (3–7) photomicrographs of acetate peels from the same specimen: (3) section at 1.40 mm showing distinctive pedicle collar in the upper part; (4) section at 1.50 mm showing the short dorsal median septum; (5, 6) sections at 1.70 and 2.60 mm, respectively, showing progression of the fused hinge plates from the earlier stages; (7) section at 2.90 mm showing crural bases with an incipiently hamiform development. (8) Specimen CCB.5.2 in which serial sections were performed; (9) transverse serial sections through CCB.5.2 (distance from the apex in mm); (10–15) photomicrographs of acetate peels from CCB.5.2: (10) section at 0.80 mm showing traces of pedicle collar and dental plate; (11, 12) sections at 2.00 and 2.20 mm, respectively, showing fused hinge plates and the hinge teeth inserted in deep sockets; (13–15) partial sections at 2.60, 3.10, and 3.80 mm, respectively, corresponding with the hamiform crural development. Scale bars = 1 cm (1, 8), 2 mm (2, 9), 1 mm (3–7, 10, 13–15), and 0.5 mm (11, 12).

Figure 5. Eurinoid microstructure of the secondary layer of the shell in some wellerelloid taxa analyzed. (1) Cirpa planifrons (Ormós, Reference Ormós1937), section at 2.20 mm from the apex in the specimen CCA.8.Cpla.X. (2) Cirpa lucentina n. sp., section at 2.30 mm from the apex in the specimen I.12.T26(26).1. (3) Cirpa briseis (Gemmellaro, Reference Gemmellaro1874), section at 2.00 mm from the apex in the specimen CCB5.2. (4) Salgirella alberti (Oppel, Reference Oppel1861), section at 2.40 mm from the apex in the specimen I.12.T26(26).2. All scale bars represent 50 μm.

Remarks

In addition to the main biometric ratios, intraspecific variability of C. briseis in the Betic domain mainly lies in the aforementioned presence of 7–12 ribs in the shell (3–4 on the median fold), as well as in the height of the fold, which ranges from low to subcynocephalous profiles. The rather flat ventral valve prevails in the stock of the Betic material, contributing to this cynocephalous-like profile, however several specimens exhibit higher grade of ventral convexity, as noted by previous authors (e.g., Principi, Reference Principi1910, pl. 3, fig. 3; Manceñido, Reference Manceñido, Pálfy and Vörös1993, pl. 1, fig. 6).

In contrast, Sacchi Vialli and Cantaluppi (Reference Sacchi Vialli and Cantaluppi1967) figured Cirpa fronto briseis with a lower folding pattern than the Betic individuals. As can be deduced, this acceptable range of variability in the folding pattern was noticed early, even in the original material studied by Gemmellaro (Reference Gemmellaro1874).

The typical costation pattern derived from the literature consists of 3 ribs restricted to the median fold, but an increasing number of ribs in this area is often reported. Even the type material displays specimens with 4 (Gemmellaro, Reference Gemmellaro1874, pl. 11, figs. 19, 20) and 3 ribs (Gemmellaro, Reference Gemmellaro1874, pl. 11, figs. 21, 22), which agrees with the individuals herein analyzed. Iñesta (Reference Iñesta1999) and Vörös et al. (Reference Vörös, Szabó, Dulai, Szente, Ebli and Lobitzer2003) also illustrated specimens with 4 ribs on the dorsal fold. Benigni (Reference Benigni1978) depicted one exceptional specimen matching with the concept of the species herein outlined with 15 ribs in the entire shell.

Cirpa briseis is a mainly Pliensbachian taxon conspicuously recorded in a huge number of western Tethyan localities. However, as shown in the synonymy list, this species has been misidentified occasionally as other closely related taxa belonging to the genera Cirpa and Salgirella. Some previous attributions to Rhynchonella alberti Oppel, Reference Oppel1861 (=Salgirella alberti) or related forms suitably could fit within the conspecific range of C. briseis (e.g., Böse and Schlosser, Reference Böse and Schlosser1900, pl. 18, fig. 1). Certainly, some external features in extreme morphologies of C. briseis can be compared with S. alberti, as can be deduced from the morphometrical analysis performed (see results section above), because both occupy nearby scores in the morphospace plots. However, this analysis also evinces the defining characters to separate them, such as the more-prominent smooth areas beside the dorsal fold or higher folding pattern in S. alberti, resulting in a deeper ventral sulcus. Salgirella alberti usually shows more widely expanded outlines as well.

Likewise, some specimens figured by Parona (Reference Parona1884, pl. 2, figs. 10–20; pl. 3, fig. 2) and Dareste de la Chavanne (Reference Dareste de la Chavanne1920) as Rhynchonella briseis do not fit in the species concept outlined here, and may correspond to other representatives ascribed to Cirpa (e.g., C. planifrons [Ormós, Reference Ormós1937]) or even to Prionorhynchia (e.g., Sulser and Furrer, Reference Sulser and Furrer2005, assigned Parona's referred material to Prionorhynchia calderinii [Parona, Reference Parona1880]). The same occurs with the specimen depicted by Haas (Reference Haas1884, pl. 1, fig. 6), which reveals wide and very deep Prionorhynchia-type planareas. Similarly, the variety iphimedia, erected by Di Stefano (Reference Di Stefano1891, pl. 3, figs. 14–17), does not agree with the range of variability of C. briseis due the presence of a high and narrow dorsal fold (with 5–7 ribs), exceeding the global thickness and giving a trilobate anterior outline to the shell.

The external features of Prionorhynchia aff. P. latifrons (Geyer, Reference Geyer1889) (Sacchi Vialli and Cantaluppi, Reference Sacchi Vialli and Cantaluppi1967, pl. 12, fig. 1) can be compared with C. briseis, but the serial sections of this material are not fully conclusive (Sacchi Vialli and Cantaluppi, Reference Sacchi Vialli and Cantaluppi1967, p. 77). Some doubts also exist regarding the attribution made by Alméras and Fauré (Reference Alméras and Fauré2000, especially the specimen depicted in pl. 11, fig. 10) due to the high degree of convexity of both valves, providing a globose profile to the shell. The same occurs with the Norman specimen figured by Alméras et al. (Reference Alméras, Cougnon, Guibbert and Fauré2014, pl. 2, fig. 3), which shows a lower folding pattern, imperceptible planareas, and higher convexity of the valves. Unfortunately, the western Algerian material is not figured for comparison (Alméras et al., Reference Alméras, Elmi and Fauré2007, p. 46). In the northern part of the Iberian Cordillera, Rodrigo (Reference Rodrigo2011) reported Cirpa cf. C. briseis, but some features, such as the absence of planareas, a more massive beak, the higher convexity of the valves, and costation consisting up to 19 ribs, prevent its inclusion in the genus Cirpa, pending verification concerning internal structure data. Finally, in Turkey, Vörös and Kandemir (Reference Vörös and Kandemir2011) figured a single poorly preserved specimen that could fit within the intraspecific variability herein described.

This species has been frequently incorporated among the diverse attributions to Rhynchonella variabilis (e.g., Geyer, Reference Geyer1889, pl. 4, figs. 19–21; Böse and Schlosser, Reference Böse and Schlosser1900, pl. 8, figs. 7, 8). Rhynchonella variabilis is a catch-all nominal species involving several taxa (most of them especially attributable to the genus Cirpa), inappropriately differentiated mainly by the number of ribs located on the median fold. Hence, some previous authors (e.g., Manceñido, Reference Manceñido, Pálfy and Vörös1993; Alméras and Fauré, Reference Alméras and Fauré2000; Siblík, Reference Siblík2002) endorsed Ager's (Reference Ager1959) early interpretation that R. variabilis is a nomen dubium that should be avoided unless it becomes more clearly defined in the future. Vörös et al. (Reference Vörös, Szabó, Dulai, Szente, Ebli and Lobitzer2003) also noted the broad interpretation in the literature of the species variabilis, which complicates the separation of C. briseis from other taxa included in that imprecise designation.

Some previous authors (e.g., Manceñido et al., Reference Manceñido, Owen, Dagys and Selden2002; Baeza-Carratalá, Reference Baeza-Carratalá2008) have regarded Cirpa primitiva (De Gregorio, Reference De Gregorio1930) as a junior subjective synonym of C. briseis. However, Vörös and Kandemir (Reference Vörös and Kandemir2011) seem not to fully agree with this opinion, arguing that many nominal species assigned to Cirpa only show minor differences, even including the original definition of the genus synonymized with C. briseis. In this work, it is preferred not to include C. primitiva in the synonymy list of C. briseis, thus retaining C. primitiva as a valid type species of the genus, given that the material of the present research does not allow clarifying this nominal topic.

Cirpa briseis can be easily differentiated from Cirpa langi Ager, Reference Ager1958, because this latter species shows more ribs, wider expanded outline, and much flatter valves. Cirpa langi carpathica (Siblík, Reference Siblík1966) shows coarser ribs, narrow folding pattern, and subquadrate anterior margin with straight lateral flanks. Cirpa lucentina n. sp. also has flatter valves and more ribs that are occasionally bifurcated. Cirpa slovenica Siblík, Reference Siblík1967, is oversized, with markedly elliptical anterior outline, and 4–7 ribs arranged on the median fold.

Cirpa fallax (Deslongchamps, Reference Deslongchamps1862)
Figure 6.7–6.18

?Reference Deslongchamps1858

Rhynchonella egretta (Nobis); Deslongchamps, p. 164, pl. 4, figs. 4–6.

Reference Deslongchamps1862

Rhynchonella fallax Deslongchamps, p. 267, pl. 3, figs. 1–5.

non Reference Davidson1884

Rhynchonella fallax Deslongchamps; Davidson, p. 275, pl. 20, figs. 4, 5.

non Reference Buckman1918

Rudirhynchia fallax (Deslongchamps); Buckman, p. 45.

non Reference Muir-Wood1928

Rudirhynchia? fallax (Deslongchamps); Muir-Wood, p. 249, fig. 6.

non Reference Ager1958

Rudirhynchia fallax (Deslongchamps); Ager, p. 83.

non Reference Ager1962

Rudirhynchia fallax (Deslongchamps); Ager, pl. 8, fig. 1.

Reference Alméras, Copper and Jin1996

Pseudogibbirhynchia fallax (Deslongchamps); Alméras, p. 8, pl. 1, figs. 4–6.

Reference Comas-Rengifo, Duarte, García Joral and Goy2013

Cirpa fallax (Deslongchamps); Comas-Rengifo et al., fig. 2.

Reference Comas-Rengifo, Duarte, Félix, García Joral, Goy and Rocha2015

Cirpa fallax (Deslongchamps); Comas-Rengifo et al., fig. 3: 7.

Figure 6. Some representative Early Jurassic species of Cirpa from the Lusitanian, Internal Subbetic, and easternmost Subbetic paleomargins. Each specimen is ordered consecutively in dorsal, anterior, and lateral views (1–18) or in dorsal, lateral, and anterior views (19–21). (1–6) Cirpa cf. C. slovenica Siblík, Reference Siblík1967; (1–3) specimen O.5.B.10.1; (4–6) specimen O.5.B.10.2 from the JdC collection. (7–18) Cirpa fallax (Deslongchamps, Reference Deslongchamps1862) from the Toarcian of Portugal; (7–9) specimen PT.33.1 from the Polymorphum Zone of Peniche; (10–18) specimens FC.6.12, FC.12.7, and FC.12.2, respectively, from the Polymorphum Zone of Fonte Coberta. (19–21) Cirpa subcostellata (Gemmellaro, Reference Gemmellaro1882), specimen SG1.CS1 from the Sinemurian of Sierra Gorda (Internal Subbetic, Granada). Scale bar = 1 cm.

Holotype

The holotype and possible syntypes originally studied and drawn by Deslongchamps (Reference Deslongchamps1858) come from the locality of May (South-Caen, Normandy, France). According to Deslongchamps (Reference Deslongchamps1858, p. 139–154), the original Rh. fallax was found in deposits filling an Ordovician relief just below the “Couche à Leptaena”. These specimens are missing because they were housed in the collections of the Museum of Caen, which was destroyed in World War II (Alméras et al., Reference Alméras, Cougnon, Guibbert and Fauré2014). This work illustrates several hypotypes (Fig. 6.7–6.18), including specimen FC.12.7 (Fig. 6.13–6.15), which is the individual showing the most relevant diagnostic criteria. A second sectioned hypotype (FC.12.31) is shown in Figure 7. The “Couche à Leptaena” are equivalent in age to the “Marly Limestones with Leptaena Fauna” (MLLF) Member of the São Gião Formation from the Polymorphum Zone at the Fonte Coberta outcrop (Portugal) (Duarte et al., Reference Duarte, Comas-Rengifo, García Joral, Goy, Míguez-Salas and Rodríguez-Tovar2018), from which the proposed hypotypes come. Both specimens are stored within the DPUCM collections.

Figure 7. Internal structure of Cirpa fallax (Deslongchamps, Reference Deslongchamps1862) from the Toarcian (Lusitanian Basin); serial sections orientated with the ventral valve up. (1) Specimen FC.12.31 in which serial sections were performed; (2) transverse serial sections through the same specimen (distance from the apex in mm); (3–5) photomicrographs of acetate peels from the same specimen: (3) section at 2.50 mm showing the fused hinge plates; also notice the interlocked dentition and the starting of the crural bases; (4) section at 1.10 mm showing the doubled (“buttressed”) deltidial plates; (5) section at 3.80 mm with a detail of the eurinoid microstructure of the shell. Scale bars = 1 cm (1), 2 mm (2), 1 mm (3, 4) and 0.5 mm (5).

Occurrence

Rhynchonella fallax Deslongchamps, Reference Deslongchamps1862, was originally described from the Middle Lias from Calvados (NW France). However, Alméras (Reference Alméras, Copper and Jin1996, p. 8) stated that, in fact, this material comes from the lower Toarcian. Its record in the peri-Iberian platforms is limited to the Polymorphum Zone of the Lusitanian Basin (corresponding to the Tenuicostatum Zone in the northwestern European areas).

Description

Small- to medium-sized equibiconvex shell, with both valves rather flat, and sub-triangular outline in dorsal view. Shell wider than long, with the maximum width in the anterior third of the shell. The subrectangular anterior profile with flattened and truncated anterior margin is representative of this species of Cirpa. Beak suberect, with a relatively large foramen, often rimmed. Lateral commissure is straight and the anterior one is uniplicate, showing a wide and low dorsal median fold, sub-rectangular in outline. Ribbing pattern consists of 15–24 (x̄ = 18.7) sharp and triangular ribs (4–8 on the median fold), frequently bifurcated in their posterior part.

Cirpa fallax shows a subrectangular to trapezoidal delthyrial cavity in cross-section, with short dental plates and double deltidial plates (Fig. 7.2, 7.4). Hinge teeth are massive and crenulated, supplemented by small denticula; teeth are inserted in crenulated sockets as well. The dorsal median septum is barely visible and septalium is absent. Hinge plates fused, parallel, and horizontal (Fig. 7.2, 7.3). Crural development is hamiform, crural bases with triangular cross-section, progressing anteriorly with short ventral development. Secondary layer of the shell shows an eurinoid pattern with rhombic cross-sectional outline of the calcite fibers (Fig. 7.5).

Remarks

Cirpa fallax is distinguished from other species of Cirpa by its large number of strong, often bifurcated ribs, and its lower lateral profile. Alméras (Reference Alméras, Copper and Jin1996, p. 8) assigned three specimens from Peniche with these external features to Pseudogibbirhynchia fallax, due to their close similarity to specimens from Rabaçal attributed to Pseudogibbirhynchia moorei (Davidson in Ager, Reference Ager1962); however, the paucity of specimens prevented the study of internal structures. Previously, Buckman (Reference Buckman1918, p. 45) included the English forms attributed by Davidson (Reference Davidson1884) to R. fallax in his new genus Rudirhynchia. This determination was subsequently followed by Muir-Wood (Reference Muir-Wood1928) and Ager (Reference Ager1958, Reference Ager1959, Reference Ager1962), but lacked data on the internal structure. However, Ager (Reference Ager, Adams and Ager1967, p. 163), after examination of new material from Somerset, considered these English forms to be upper Sinemurian in age, different from the Norman species, and even attributed this material to Prionorhynchia greppini (Oppel, Reference Oppel1861).

Three sectioned specimens from Rabaçal and Peniche reveal the characteristic internal features of the genus Cirpa, particularly the fused cardinal plates and double strengthened deltidial plates (Fig. 7). This led Comas-Rengifo et al. (Reference Comas-Rengifo, Duarte, García Joral and Goy2013, Reference Comas-Rengifo, Duarte, Félix, García Joral, Goy and Rocha2015) to reconsider the generic position of Rh. fallax, arranging the Portuguese material in the genus Cirpa.

Specimens of the original “Rhynchonella” fallax, which are only known from drawings, are probably missing, as unfortunately occurred with many parts of the Deslongchamps collections, because of the destruction of the Caen Museum in World War II (Alméras et al., Reference Alméras, Cougnon, Guibbert and Fauré2014). Attribution of the specimens studied to “Rh.” fallax is based on the conclusions of Alméras (Reference Alméras, Copper and Jin1996). Nevertheless, the nominal species “Rhynchonella egretta” by Deslongchamps (Reference Deslongchamps1858, p. 164, pl. 4, figs. 4–6) from the same “Leptaena Beds” of May (Calvados) could also be related to the Portuguese specimens. Drawings of the specimens of this taxon show the bifurcated (or intercalated) ribs that are common in C. fallax from Portugal and equally low lateral profile, although the median fold is much more pronounced. In the original description, this material is associated with numerous species of thecideides, koninckinides, spiriferinides, terebratulides, and rhynchonellides, including Pseudokingena deslongchampsi (Davidson, Reference Davidson1850), Koninckella liasina (Bouchard in Davidson and Morris, Reference Davidson and Morris1847), and Nannirhynchia pygmaea (Morris in Davidson and Morris, Reference Davidson and Morris1847), which is similar to the assemblage where C. fallax is recorded in the Lusitanian Basin. Because the original type specimens are missing due to the destruction of the Museum of Caen, it remains unclear whether the Portuguese Cirpa and Rh. egretta are conspecific, thus we retain the specific attribution proposed by Alméras (Reference Alméras, Copper and Jin1996).

Holotype

Specimen CCA.8.Clat.1 (Fig. 3.1–3.3). Dimensions (in mm): L: 16.73; W: 18.31; T: 9.04. Type locality: Cerro de la Cruz de La Romana, Alicante Province, Betic Cordillera, Spain. Red crinoidal grainstone member of the Gavilán Formation; Pliensbachian. Deposited in the collections of the DCTMA (University of Alicante, Spain).

Diagnosis

Medium-sized multicostate Cirpa with rather flat valves. Beak small with short and slightly depressed planareas. Anterior commissure uniplicate in a wide dorsal median fold; with numerous ribs, occasionally bifurcate; pedicle collar present, double triangular deltidial plates; fused subhorizontal hinge plates, hamiform crura.

Occurrence

In the Subbetic Domain, the material updated as C. lucentina n. sp. was cited by Jiménez de Cisneros (Reference Jiménez de Cisneros1923) in the “Middle Lias.” Baeza-Carratalá (Reference Baeza-Carratalá2013) restricted the distribution range of this taxon in the Subbetic and the Prebetic/Subbetic transitional zones (Baeza-Carratalá et al., Reference Baeza-Carratalá, García Joral and Tent-Manclús2016b) to the late Pliensbachian.

Description

Medium-sized biconvex shells with both valves rather flat. Shell wider than long and the thickness is about half its width. The maximum width lies around the mid-length and the maximum thickness is shifted toward the posterior third of the shell. Dorsal outline is triangular with a rounded anterior margin. The beak is small and strong, suberect, and shows a minute pedicle foramen. Narrow, faintly defined beak ridges bordering slightly depressed planareas that are poorly developed on the flanks. Commissure is straight laterally and uniplicate at anterior margin, showing a low, arcuate, and wide dorsal median fold. Multicostate shell, displaying 13–16 ribs running along the entire shell length, triangular in cross-section (4–6 of which are present on the median fold). It is not unusual to detect bifurcations originating from the posterior third of the shell.

In its internal structure (Fig. 8), posterior subelliptical delthyrial cavity and semicircular umbonal cavities are visible. Pedicle collar present. Double deltidial plates, triangular in cross-section. Dental plates are straight and subparallel. Hinge teeth and sockets are crenulated, also developing small denticula. Dorsal median septum very short. Hinge plates are slender and fused, parallel to the commissural plane. They initially show a slight ventral orientation, anteriorly becoming straight and subparallel. Hamiform crural development, with relatively large comma-shaped crural endings (Fig. 8). Secondary layer of the shell shows an eurinoid pattern, featuring fibers with rhombic/subquadrate outline in cross section, ~60–80 μm wide and 30–50 μm thick (Fig. 5.2).

Figure 8. Internal structure of Cirpa lucentina n. sp. from the Pliensbachian (Eastern Prebetic); serial sections orientated with the ventral valve up. (1) Specimen I.12.T26(26).1 in which serial sections were performed; (2) transverse serial sections through the same specimen (distance from the apex in mm); (3–5) photomicrographs of acetate peels from the same specimen: (3) section at 0.30 mm showing distinctive pedicle collar between dental plates; (4) section at 1.40 mm showing the short dorsal median septum; (5) section at 1.70 mm showing fused hinge plates and insertion of hinge teeth in sockets. Scale bars = 1 cm (1), 2 mm (2), and 1 mm (3–5).

Etymology

From the Latin, Lucentum, the ancient toponym of Alicante, the region where this species is recorded for the first time.

Remarks

Intraspecific variability of Cirpa lucentina n. sp. mainly lies in the number of costae, which is increased by bifurcation in some individuals. Moreover, while the valves are consistently flat, several specimens show slightly dorsibiconvex profiles (e.g., Jiménez de Cisneros, Reference Jiménez de Cisneros1923). In addition, the anterior folding shape can vary from the representative arcuate/semicircular to straight/subrectangular outlines.

As can be deduced from the synonymic list, specimens of Cirpa lucentina n. sp. were related and assimilated as possible Betic counterparts of the species Rhynchonella latifrons Geyer, Reference Geyer1889, and were assigned in open nomenclature to Cirpa aff. C. latifrons in the latest papers (Baeza-Carratalá, Reference Baeza-Carratalá2004, Reference Baeza-Carratalá2008, Reference Baeza-Carratalá2013; Baeza-Carratalá et al., Reference Baeza-Carratalá, García Joral and Tent-Manclús2016b). This attribution was based upon the external features (i.e., folding pattern, flattened valves, even specimens bearing bifurcated ribs), except for the development of (often short) planareas in the Betic specimens, which apparently are comparable with the records of the Austrian Alps where the types of Rhynchonella latifrons were defined by Geyer (Reference Geyer1889). In this sense, Rh. latifrons was tentatively attributed to Cirpa by several previous authors (Dulai, Reference Dulai1992, Reference Dulai2003; Böhm et al., Reference Böhm, Ebli, Krystin, Lobitzer, Rakús and Siblík1999, Vörös et al., Reference Vörös, Szabó, Dulai, Szente, Ebli and Lobitzer2003; Baeza-Carratalá, Reference Baeza-Carratalá2004). This attribution to the genus Cirpa was consistent with the internal structure revealed by the Subbetic stock (Fig. 8), with double deltidial plates, fused hinge plates, and hamiform crura. Thus, Baeza-Carratalá (Reference Baeza-Carratalá2008, Reference Baeza-Carratalá2013) proposed the combination Cirpa aff. C. latifrons.

Unravelling the taxonomy of lowermost Jurassic multicostate rhynchonellids, Tomašových (Reference Tomašových2006) thoroughly revised the attributions of Rh. latifons (Geyer, Reference Geyer1889). The very comprehensive analysis of the internal structure in such specimens revealed that the Hettangian–Sinemurian “true latifrons” from the Western Carpathians and the Austrian Alps evolved disjoint hinge plates inclined forming a sessile septalium, no pedicle collar, and subfalciform crura. This evidence led to erection of a new genus (Jakubirhynchia Tomašových, Reference Tomašových2006), with Jakubirhynchia latifrons (Geyer, Reference Geyer1889) as type species, separate from Cirpa, even at the Superfamily level (Cirpa = Wellerelloidea; Jakubirhynchia = Pugnacoidea).

Bearing in mind that the Betic material undoubtedly can be placed in the genus Cirpa, it should be split from the J. latifrons stock, and we consider it herein as new species. Additionally, both biostratigraphical ranges are unconnected since Jakubirhynchia latifrons is regarded hitherto as a representative species from the Hettangian–Sinemurian, while C. lucentina n. sp. is recorded in the late Pliensbachian.

On the other hand, the material recorded in the easternmost Subbetic and the Prebetic/Subbetic transitional areas of La Mola region differs from several comparable species assigned to Cirpinae, such as Calcirhynchia plicatissima (Quenstedt, Reference Quenstedt1852), which shows higher convexity on both valves and narrower dorsal outline. Cirpa planifrons shows anteriorly truncated dorsal outline and narrower fold, and Cirpa subcostellata (Gemmellaro, Reference Gemmellaro1882) has fewer ribs overall. Finally, among the Jakubirhynchia representatives, Jakubirhynchia? fascicostata (Uhlig, Reference Uhlig1879) externally differs in having more convex valves and numerous ribs.

Possible equivalents of the new species herein erected may be the specimens assigned to Prionorhynchia latifrons by Sacchi Vialli and Cantaluppi (Reference Sacchi Vialli and Cantaluppi1967), which show a narrower dorsal median fold, fitting within the intraspecific variability of this taxon. Moreover, the partial serial sections performed by the aforementioned authors (Sacchi Vialli and Cantaluppi, Reference Sacchi Vialli and Cantaluppi1967, p. 76, text-fig. 4) might be attributable to the genus Cirpa, but they are not conclusive because the entire crural development is not clear.

Holotype

The holotype of this species was described and figured by Ormós (Reference Ormós1937, p. 41, pl. 1, fig. 19). Sinemurian (Oxynotum Zone) from the “Unteren Lias-Schichten,” Kékhegy, Bakony Mts., Hungary.

Occurrence

The original Rhynchonella planifrons Ormós (Reference Ormós1937) was cited in the Sinemurian (Oxynotum Chronozone) from Hungary. Most of the occurrences of this species were reported from the Sinemurian: the Marmorea Zone from Northern Calcareous Alps (Siblík, Reference Siblík1993a); from Schafberg (Austria) (Vörös et al., Reference Vörös, Szabó, Dulai, Szente, Ebli and Lobitzer2003); and from the Hettangian–late Sinemurian of the Bakony Mts. (Hungary) (Dulai, Reference Dulai2003; Vörös and Dulai, Reference Vörös and Dulai2007). Mandl et al. (Reference Mandl, Dulai, Schlögl, Siblík, Szabó, Szente and Vörös2010) recorded this taxon in the Sinemurian–Pliensbachian? from Austria. The occurrence in the peri-Iberian platforms is limited to the Pliensbachian from the eastern Subbetic domain.

Description

Medium-sized equibiconvex shell, with both valves rather flat and with triangular outline in dorsal view. Shell wider than long, except for several specimens that show nearly equidimensional W/L ratios. Maximum width lies in the anterior third of the shell, slightly shifted toward the anterior margin. The subrectangular outline in the anterior view, with flattened and truncated anterior margin, is representative of this species of Cirpa. The beak is small, strong, suberect, and shows a minute pedicle foramen and poorly developed beak ridges. Well-developed but shallow planareas. Lateral commissure is straight; anterior commissure is uniplicate, showing a wide dorsal median fold, rectangular in outline. Ribbing pattern consists of 10–14 sharp, narrow, and triangular ribs (4–6 on the median fold).

Cirpa planifrons shows a subrectangular delthyrial cavity in cross-section, with a strong pedicle collar and well-developed deltidial plates (Fig. 9). Dental plates are short and subparallel. Hinge teeth are massive and crenulated, supplemented by small denticula, teeth are inserted in concomitantly crenulated sockets. The dorsal median septum is ephemeral; it is observed along 10 μm in cross-section, and the septalium is absent (Fig. 9.2). Hinge plates persistently fused, parallel, and horizontal (Fig. 9.2, 9.7). Crural development is hamiform, crural bases with triangular cross-section, progressing anteriorly with ventral development and revealing endings with inverted U-shaped section. Secondary layer of the shell shows an eurinoid pattern, with rhombic cross-sectional outline of the calcite fibers ~50–70 μm wide and 20–25 μm thick (Fig. 5.1).

Figure 9. Internal structure of Cirpa planifrons (Ormós, Reference Ormós1937) from the Pliensbachian (Eastern Prebetic); serial sections orientated with the ventral valve up. (1) Specimen CCA.8.Cpla.X in which serial sections were performed; (2) transverse serial sections through the same specimen (distance from the apex in mm); (3–10) photomicrographs of acetate peels from the same specimen: (3) section at 1.00 mm showing pedicle collar (black arrow) and well-developed deltidial plates; (4–7) sections at 2.30, 2.50, 2.70, and 2.90 mm, respectively, showing evolution of the fused hinge plates and progression of the articulation with the features of hinge teeth and sockets; (8–10) sections at 3.50, 3.80, and 4.10 mm, respectively, showing hamiform crural (black arrows) development progressing ventrally anteriorly with inverted U-shaped sections distally. Scale bars = 1 cm (1), 2 mm (2), and 0.5 mm (3–10).

Remarks

Cirpa planifrons shows a relatively low degree of intraspecific variability in the Subbetic material. Similar patterns of ribbing are noted both in the number of total ribs and in those confined on the median fold. Only a single specimen with one bifurcated rib was observed, as was earlier depicted in the previous literature (Siblík, Reference Siblík1993a; Vörös et al., Reference Vörös, Szabó, Dulai, Szente, Ebli and Lobitzer2003). The standard flattened valves can acquire a slight degree of convexity in some specimens, as was reported by Siblík (Reference Siblík1993a, Reference Siblík, Pálfy and Vörösb). Juvenile specimens tend to be equidimensional, deviating from the usual wider than long biometric proportion of adults. This condition is also noticed in the material recorded by Dulai (Reference Dulai2003). Mandl et al. (Reference Mandl, Dulai, Schlögl, Siblík, Szabó, Szente and Vörös2010) depicted specimens with high degree of convexity and rather developed dorsal median fold, both features influencing the folding pattern, which differs from typical specimens assigned to this species. Specimens from western Algeria (Alméras et al., Reference Alméras, Elmi and Fauré2007) cannot be compared due the absence of illustrations of the two incomplete specimens cited. Siblík (Reference Siblík1993a) and Siblík and Lobitzer (Reference Siblík and Lobitzer2008) partially sectioned this species, matching well the total progression of the internal architecture herein revealed (Fig. 9).

Cirpa planifrons differs from C. lucentina n. sp. in having a more rectangular and truncated anterior margin, as well as straight flanks. Cirpa fronto (Quenstedt, Reference Quenstedt1871) shows fewer and coarser ribs over the entire shell surface, as reported by Siblík (Reference Siblík, Pálfy and Vörös1993b) and Vörös et al. (Reference Vörös, Szabó, Dulai, Szente, Ebli and Lobitzer2003).

Holotype

The specimen MS-164 deposited in the collection of the Geological Survey of Prague was originally designated as the holotype of Cirpa slovenica (Siblík, Reference Siblík1967, pl. 9, fig. 1) and was collected in the uppermost beds of the Domerian from the Kostelec locality.

Occurrence

Siblík (Reference Siblík1967) recorded this species in the latest Pliensbachian from Slovakia. The Subbetic material is attributed to late Pliensbachian as well.

Description

Medium- to large-sized dorsibiconvex shell, considerably wider than long. The dorsal outline is subpentagonal with a rounded anterior margin. The beak is suberect, showing a small pedicle foramen; the beak ridges are sharp in the posterior third of the shell. Well-developed smooth, narrow, and shallow planareas. Squama-glotta present near the beak (Fig. 6.6), then the lateral commissure running straight with ventral-tilted orientation. Anterior commissure is uniplicate, with a wide subtrapezoidal dorsal median fold. Fully costate shell consisting of 13–16 sharp and triangular ribs (4–7 of which occur on the median fold), without bifurcation. Growth lines are poorly visible, only on the planareas. Available material is not suitable for making serial sections.

Remarks

Specimens herein analyzed have been attributed to Cirpa cf. C. slovenica due to the considerable external similarity with the type material described and figured by Siblík (Reference Siblík1967), because the Subbetic material differs only in having a higher folding pattern. The Subbetic material assigned to C. cf. C. slovenica corresponds with a large morphotype of Cirpa, comparable with the largest figured specimens of C. briseis (e.g., Di Stefano, Reference Di Stefano1891). Nevertheless, the widely expanded profile and greater number of ribs (both on the shell over and on the median dorsal fold) allow separating our specimens from C. briseis.

Holotype

The type specimen was figured in four views (dorsal, anterior, lateral, and ventral) by Gemmellaro (Reference Gemmellaro1882, pl. 31, figs. 75–78). It was collected from the “Lower Liassic” of Sicily, and is deposited in the collections of the University of Palermo.

Occurrence

Sinemurian–Early Pliensbachian from the Transdanubian Ranges (Vörös and Dulai, Reference Vörös and Dulai2007) and Sicily (Gemmellaro, Reference Gemmellaro1882); Sinemurian from Northern Calcareous Alps (Vörös et al., Reference Vörös, Szabó, Dulai, Szente, Ebli and Lobitzer2003; Mandl et al., Reference Mandl, Dulai, Schlögl, Siblík, Szabó, Szente and Vörös2010); late Sinemurian–early Pliensbachian (Raricostatum–Aenigmaticum zones) from western Algeria (Elmi et al., Reference Elmi, Alméras, Benhamou, Mekahli and Marok2003; Alméras et al., Reference Alméras, Elmi and Fauré2007). Sinemurian (Turnieri–Raricostatum? zones) from the Subbetic area (Baeza-Carratalá et al., Reference Baeza-Carratalá, Dulai and Sandoval2018b; this work).

Description

The specimens recorded present a subpentagonal, widely expanded dorsal outline, showing an uniplicate folding pattern with a low, narrow, and trapezoidal dorsal fold. The multicostate shell displays 14 densely packed and acute ribs (4 on the median fold), often bifurcate. The flanks of the shell show shallow and well-developed planareas. There is not enough material available for studying the internal structure.

Remarks

Vörös (Reference Vörös2009) thoroughly described and discussed this taxon and we fully agree with the interpretation that this author gives to C.? subcostellata. The few differences found in the Betic material with respect to those synonymized above are the presence of lower and lesser-constrained anterior uniplication and longer interareas. We also agree with the opinion of Vörös (Reference Vörös2009) about giving an open generic nomenclature, awaiting better-preserved material to understand the internal structure of this species. On the basis of the external criteria, such as the beak features and the ribbing and folding patterns, it seems appropriate to assign this taxon provisionally to the genus Cirpa.

Type species

Rhynchonella albertii Oppel, Reference Oppel1861.

Remarks

Since erection of the genus Salgirella in the “Middle Lias” of Crimea by Moisseiev (Reference Moisseiev1936), the generic usage of Salgirella, separate from Cirpa, has been widely extended principally for reporting the type species Salgirella alberti (Oppel), largely widespread in the Mediterranean and Pontic biochoremas of the western Tethys. Several other reports of Salgirella, mainly in the Mediterranean bioprovince (e.g., S.? magnicostata [Ormós, Reference Ormós1937], S.? goicoecheai Baeza-Carratalá, Reference Baeza-Carratalá2011) would suggest that the separation of both genera may be appropriate. However, Cirpa and Salgirella have been considered as possible synonyms by some previous authors (e.g., Manceñido et al., Reference Manceñido, Owen, Dagys and Selden2002). According to the original diagnosis of Moisseiev and subsequent works of this author, Salgirella is typified by pentagonal-rounded dorsal outlines, with robust and incurved beak, acute and coarse ribs, short dental plates detached early from the ventral valve, deltidial plates with undulate curvature, short and poorly developed dorsal median septum, integral fused hinge plates, and septalium present. All of these characters, together with several morphometrical parameters herein analyzed (e.g., length of smooth areas separating median fold and flanks, ribbing pattern, widely expanded profile), are distinctive enough to justify a consistent basis for its taxonomic distinction from the genus Cirpa along with some additional criteria.

Internal structure.—The internal structure of both genera is similar regarding the crural architecture, with hamiform development and initially fused hinge plates. The dorsal septum is extremely short in both genera (a bit larger in Salgirella), but Salgirella is distinguished from Cirpa by the presence of a short U-shaped septalium. Distinctive double deltidial plates of Cirpa are not so clearly evident in Salgirella (this genus exhibiting a triangular cross section of deltidial plates), but more data are required to substantiate this last feature.

External structure.—Morphometric analysis of the dataset including all peri-Iberian cirpines has revealed a stock of Salgirella with more pronounced and wider smooth areas developed alongside the dorsal median fold than in representatives of genus Cirpa. This also implies more-spaced ribs in these areas resulting a deeper corresponding ventral sulcus. These external attributes may be considered as additional diagnostic criteria for Salgirella, combined with those proposed by previous authors, such as widely expanded outlines or the beak features, among others.

Salgirella alberti (Oppel, Reference Oppel1861)
Figure 10

Reference Oppel1861

Rhynchonella Albertii Oppel, p. 546, pl. 13, fig. 4.

Reference Uhlig1879

Rhynchonella Albertii Oppel; Uhlig, p. 32, pl. 4, fig. 1.

non Reference Uhlig1879

Rhynchonella Albertii Oppel var. sospirolensis; Uhlig, p. 32, pl. 4, fig. 2.

Reference Geyer1889

Rhynchonella Alberti Oppel; Geyer, p. 43, pl. 5, figs. 14–17.

Reference Geyer1889

Rhynchonella Alberti Oppel var. lobata; Geyer, p. 45, pl. 5, fig. 18.

?Reference Fucini1895

Rhynchonella Alberti Oppel; Fucini, p. 172, pl. 7, fig. 1.

?Reference Böse and Schlosser1900

Rhynchonella sp. aff. Alberti Oppel; Böse and Schlosser, p. 193, pl. 18, fig. 1.

?Reference Principi1910

Rhynchonella Alberti Oppel; Principi, p. 79, pl. 3, fig. 8.

non Reference Haas1912

Rhynchonella n. sp. ind. ex aff. Alberti Oppel; Haas, p. 241, pl. 19(1), fig. 16.

Reference Dareste de la Chavanne1920

Rhynchonella Albertii Oppel; Dareste de la Chavanne, p. 18, pl. 1, fig. 5.

Reference Ormós1937

Rhynchonella alberti var. lobata Geyer; Ormós, p. 25, pl. 1, fig. 7.

non Reference Ormós1937

Rhynchonella alberti var. minor; Ormós, p. 25, pl. 1, figs. 8, 9.

Reference Berg, Krimholz, Moisseiev, Mjatliuk, Petrova, Pcelincev, Riabinin, Tchernyshev, Sharapova and Yakowlew1947

Salgirella alberti (Oppel); Moisseiev in Berg et al., p. 91, pl. 5, fig. 3.

cf. Reference Dulai1993

Salgirella cf. albertii (Oppel); Dulai, p. 30, pl. 1, fig. 2.

Reference Manceñido2002

Salgirella alberti (Oppel); Manceñido et al., p. 1266, fig. 862 (1).

cf. Reference Dulai2003

Salgirella cf. alberti (Oppel); Dulai, p. 29, pl. 5, figs. 7–10.

Reference Vörös and Dulai2007

Salgirella albertii (Oppel); Vörös and Dulai, p. 54, pl. 1, figs. 17, 18.

Reference Baeza-Carratalá2008

Salgirella albertii (Oppel); Baeza-Carratalá, p. 178, pl. 8, figs. 1–6.

Reference Siblík and Lobitzer2008

Salgirella albertii (Oppel); Siblík and Lobitzer, p. 66, pl. 1, fig. 2.

Reference Mandl, Dulai, Schlögl, Siblík, Szabó, Szente and Vörös2010

Salgirella cf. albertii (Oppel); Mandl et al., p. 93, pl. 2, fig. 8; pl. 6, fig. 6.

Reference Mandl, Dulai, Schlögl, Siblík, Szabó, Szente and Vörös2010

Salgirella albertii (Oppel); Mandl et al., p. 91, pl. 7, fig. 6(9); pl. 9, fig. 5.

Reference Vörös2014

Salgirella alberti (Oppel); Vörös, p. 22, figs. 24–26.

Reference Baeza-Carratalá, Dulai and Sandoval2018b

Salgirella alberti (Oppel); Baeza-Carratalá et al., p. 374, fig. 4 (8–10).

Figure 10. Some representative Early Jurassic specimens of Salgirella alberti (Oppel, Reference Oppel1861) from the Subbetic paleomargin. (1, 2) Specimen LL.al.1 (dorsal and anterior views, respectively); (3, 4) specimen LL.al.2 (dorsal and anterior views, respectively); (1–4) derive from the Pliensbachian-Toarcian transition from Las Losillas (External Subbetic, Murcia); (5–8) specimen I.14.3.9 from the JdC collection (views are ordered consecutively in dorsal, anterior, lateral, and ventral views); (9–11) specimen I.15.3.12 from the JdC collection (dorsal, anterior, and ventral views, respectively); (12–15) specimen O.8.20.T5.1 from the Pliensbachian of Sierra de Quibas (External Subbetic, Murcia); views are ordered consecutively in dorsal, anterior, lateral, and ventral views; (16–18) specimen SGA1.SA1 (dorsal, anterior, and lateral views respectively) from the Sinemurian of Sierra Gorda (Internal Subbetic, Granada). Scale bar = 1 cm.

Holotype

The single specimen figured as Rhynchonella Albertii by Oppel (Reference Oppel1861, pl. 13, fig. 4), stored in the Museum für Naturkunde (Berlin) and collected from the Hierlatz limestones Formation.

Occurrence

This species is frequently reported in the classical literature (e.g., Oppel, Reference Oppel1861; Geyer, Reference Geyer1889; Ormós, Reference Ormós1937). Among the numerous localities where S. alberti is recorded, notable are those from the Sinemurian from the Northern Calcareous Alps (Geyer, Reference Geyer1889; Vörös et al., Reference Vörös, Szabó, Dulai, Szente, Ebli and Lobitzer2003; Siblík and Lobitzer, Reference Siblík and Lobitzer2008; Mandl et al., Reference Mandl, Dulai, Schlögl, Siblík, Szabó, Szente and Vörös2010) and Crimea and Caucasus (Moisseiev, Reference Moisseiev1934; Moisseiev in Berg et al., Reference Berg, Krimholz, Moisseiev, Mjatliuk, Petrova, Pcelincev, Riabinin, Tchernyshev, Sharapova and Yakowlew1947); from the Hettangian–late Sinemurian of the Transdanubian Ranges (Dulai, Reference Dulai1993, Reference Dulai2003; Vörös and Dulai, Reference Vörös and Dulai2007); from the Pliensbachian of the Subbetic (Baeza-Carratalá, Reference Baeza-Carratalá2013; Baeza-Carratalá et al., Reference Baeza-Carratalá, Dulai and Sandoval2018b); from the Pliensbachian of Turkey (Vörös, Reference Vörös2014) or the North African basins (Dareste de la Chavanne, Reference Dareste de la Chavanne1920).

Description

This species was recently exhaustively described and discussed in several western Tethys biochoremas (Dulai, Reference Dulai2003; Vörös and Dulai, Reference Vörös and Dulai2007; Baeza-Carratalá, Reference Baeza-Carratalá2008; Vörös, Reference Vörös2014; Baeza-Carratalá et al., Reference Baeza-Carratalá, Dulai and Sandoval2018b; among others) and well illustrated over the last decades, as can be deduced from the synonymy list, and does not need further detailed systematic external description, but its great intraspecific variability justifies an abridged description of S. alberti in the peri-Iberian paleomargins, thus substantiating our interpretation of this taxon. Betic material of this species corresponds to medium-sized dorsibiconvex shells, with triangular/subpentagonal to pyriform dorsal outline. W/L ratio is rather variable. Maximum width lies on the anterior third of the shell. The beak is broad, strong, and slightly incurved, with a minute pedicle foramen; the beak ridges are short and barely perceivable, and planareas are not well developed. Commissure is straight laterally and uniplicate at anterior margin, with a narrow and subtrapezoidal to arcuate dorsal median fold. Coarsely ribbed shell, with 9–13 triangular ribs (2–4 on the median fold) without bifurcation. There are well-developed flat, smooth, areas just adjacent to the median fold, clearly separating the top of the dorsal fold from the flanks of the shell.

Serial sections of S. alberti (Fig. 11) show a rectangular delthyrial cavity and semicircular umbonal cavities. Pedicle collar is present. Deltidial plates are triangular in cross-section. Dental plates short, initially divergent, then subparallel. Hinge teeth massive and crenulated, as are the sockets. Small denticula visible. A short dorsal median septum and a poorly developed, shallow, wide, U-shaped septalium are discernible. Fused hinge plates flat and subhorizontal. Hamiform crural development, with comma-shaped crural plates (Fig. 11.2, 11.5). Secondary layer of the shell shows an eurinoid pattern, with rhombic/subrectangular cross-sectional outline of the calcite fibers, ~50–60 μm wide and 20–30 μm thick (Fig. 5.4).

Figure 11. Internal structure of Salgirella alberti (Oppel, Reference Oppel1861) from the Pliensbachian (Eastern Prebetic); serial sections orientated with the ventral valve up. (1) Specimen I.12.T26(26).2 in which serial sections were performed; (2) transverse serial sections through the same specimen (distance from the apex in mm); (3–5) photomicrographs of acetate peels from the same specimen: (3) section at 1.10 mm showing dorsal median septum and short septalium; (4) section at 1.90 mm showing the final part of the fused hinge plates; also notice the interlocked dentition and the beginnings of the crural bases; (5) section at 3.30 mm with separated hamiform crura. Scale bars = 1 cm (1), 2 mm (2), and 1 mm (3–5).

Remarks

Although variability of this species has been extensively analyzed and discussed by previous authors (Moisseiev in Berg et al., Reference Berg, Krimholz, Moisseiev, Mjatliuk, Petrova, Pcelincev, Riabinin, Tchernyshev, Sharapova and Yakowlew1947; Dulai, Reference Dulai2003; Vörös and Dulai, Reference Vörös and Dulai2007; Baeza-Carratalá, Reference Baeza-Carratalá2008; Mandl et al., Reference Mandl, Dulai, Schlögl, Siblík, Szabó, Szente and Vörös2010; Vörös, Reference Vörös2014; Baeza-Carratalá et al., Reference Baeza-Carratalá, Dulai and Sandoval2018b; among others), short remarks about the Betic material must be emphasized due to the great variability reported in the previous literature. Baeza-Carratalá (Reference Baeza-Carratalá2008) and Baeza-Carratalá et al. (Reference Baeza-Carratalá, Dulai and Sandoval2018b) indicated that the intraspecific variability of this species can vary between two extreme morphotypes: that from Salgir River, with larger and robust beak, fewer and stronger ribs, and narrower outline, referred to by Manceñido et al. (Reference Manceñido, Owen, Dagys and Selden2002) and considered by several previous authors (e.g., Dareste de la Chavanne, Reference Dareste de la Chavanne1920; Baeza-Carratalá, Reference Baeza-Carratalá2008, Reference Baeza-Carratalá, Dulai and Sandoval2018b, part); versus the classical long-established morphotype intended by Oppel (Reference Oppel1861), showing wider outline, pointed beak, and more prominent dorsal fold. The Pliensbachian material in the Subbetic basins shows both extremes of variability. Moreover, the westernmost Subbetic specimens, Pliensbachian in age, have more-pronounced smooth areas developed just adjacent to the median fold than the Sinemurian material from the Internal Subbetic (Baeza-Carratalá et al., Reference Baeza-Carratalá, Dulai and Sandoval2018b).

The costation is a relatively consistent character. Specimens displaying 11 ribs on the entire shell are the most frequent, often with a variable number of ribs located on the median fold (and thus in the ventral sinus, where commonly 2–3 ribs occur). Some other variable features are related to the median dorsal fold (e.g., its outline ranging from higher subtriangular to trapezoidal and lower in shape).

Concerning the internal structure, short dental plates and septum, presence of septalium, and crural development suggest inclusion in the genus Salgirella. The specimen sectioned in this work agrees well with Moisseiev's material (Moisseiev in Berg et al., Reference Berg, Krimholz, Moisseiev, Mjatliuk, Petrova, Pcelincev, Riabinin, Tchernyshev, Sharapova and Yakowlew1947) and with the serial sections depicted by Manceñido et al. (Reference Manceñido, Owen, Dagys and Selden2002). Only minor variations can be detected, such as a shorter dorsal median septum in the Subbetic material than that from Salgir River sectioned by Lobacheva and illustrated by Manceñido et al. (Reference Manceñido, Owen, Dagys and Selden2002) and, in turn, Moisseiev in Berg et al. (Reference Berg, Krimholz, Moisseiev, Mjatliuk, Petrova, Pcelincev, Riabinin, Tchernyshev, Sharapova and Yakowlew1947) showed shorter dental plates than the Subbetic material.

As specified above, the folding pattern of Cirpa briseis is comparable to and usually difficult to distinguish from S. alberti, if we consider that they are commonly recorded together in several western Tethyan basins. In this sense, S. alberti develops wider smooth areas on both flanks of the dorsal median fold and more-spaced ribs, especially noticed in these areas in the corresponding ventral valve sulcus (Fig. 10).

The variety sospirolensis (Uhlig, Reference Uhlig1879) is not conspecific with S. alberti (Oppel), because it differs in having wide and deeper Prionorhynchia-type planareas. The same is applicable to the specimen figured by Principi (Reference Principi1910), which was tentatively assigned by Vörös (1994) to the genus Homoeorhynchia. The very flat dorsal valve and lesser development of contiguous areas to the median fold figured by Fucini (Reference Fucini1895) or Böse and Schlosser (Reference Böse and Schlosser1900) could fit better in the conspecific range of Cirpa briseis. The complex taxonomical combination Rhynchonella n. sp. ind. ex affin. alberti, adopted by Haas (Reference Haas1912), has smooth posterior stage; it was revised as Homoeorhynchia? lubrica by Vörös (Reference Vörös2009), whereas the variety minor (Ormós, Reference Ormós1937) shows densely packed ribs, flatter valves, and wider uniplication.

Apart from the aforementioned frequently misidentified C. briseis-S. alberti, the closest species is Salgirella? magnicostata (Ormós, Reference Ormós1937), but the latter taxon is larger and has a strong ribbing pattern.

Finally, concerning the spelling adopted as valid for this species name, even though Oppel (Reference Oppel1861, p. 546) correctly formed a genitive from the surname Alberti, we agree with Vörös (Reference Vörös2014, p. 22) that the emendation to “alberti” by Geyer (Reference Geyer1889, p. 43, with the mandatory change of Art. 28) corresponds to a prevailing usage (cf., synonym list above), deemed to be a correct original spelling, to be preserved under Art. 33.3.1 of the ICZN (1999).

Salgirella? goicoecheai Baeza-Carratalá, Reference Baeza-Carratalá2011
Figure 12

Reference Baeza-Carratalá2008

Salgirella? goicoecheai Baeza-Carratalá, p. 185, pl. 9, figs. 3, 4.

Reference Baeza-Carratalá2011

Salgirella? goicoecheai Baeza-Carratalá, p. 350, fig. 2 (3, 4).

Figure 12. Endemic Pliensbachian species Salgirella? goicoecheai Baeza-Carratalá, Reference Baeza-Carratalá2011, from the Subbetic paleomargin. (1–3) Specimen O.7.22.2 (holotype) from the Moleta de Togores outcrop (JdC collection); views are ordered consecutively in dorsal, anterior, and lateral views; (4–6) specimen O.7.22.1 from the Moleta de Togores outcrop (JdC collection); views are ordered consecutively in dorsal, anterior, and lateral views; (7–10) specimen CI4550 derived from the Pliensbachian of Cerro de La Cruz-1 (Peiró collection, MUPE); views are ordered consecutively in dorsal, anterior, lateral, and ventral views; (11) fragmented specimen CCA.10.Sgo.CH (anterior view) from the Pliensbachian of Cerro de la Cruz-1; (12–14) specimen CI4548 derived from the Pliensbachian of Cerro de La Cruz-1 (Peiró collection, MUPE); views are ordered consecutively in dorsal, anterior, and ventral views. Scale bar = 1 cm.

Holotype

Specimen O.7.22.2 selected by Baeza-Carratalá (Reference Baeza-Carratalá2011, fig. 2.3) and figured herein (Fig. 12.1–12.3), deposited at the Paleontological Museum of Murcia, Spain (JdC collection). Middle–late Pliensbachian from the Cerro de La Cruz of La Romana (Alicante, Spain). Upper member of the Gavilán Formation.

Occurrence

This species is endemic to the Eastern Subbetic Domain, and it is recorded from the late Pliensbachian.

Description

This is a large-sized multicostate rhynchonellide that was erected as a new species endemic to the Subbetic area by Baeza-Carratalá (Reference Baeza-Carratalá2011). It is pentagonal and wider than long in dorsal outline. The beak is wide and suberect and the dorsal folding pattern consists of a trapezoidal and wide uniplication corresponding with a well-marked ventral sulcus. Ribbing pattern consists of 16–23 densely packed, acute, and triangular ribs (5–8 on the dorsal fold) without bifurcation.

Remarks

Because the internal structure remains unknown owing to inadequate material for making serial sections, the beak features, folding pattern, presence of wide smooth areas separating the dorsal median fold from both flanks, and the very remarkable ventral sulcus have been considered as discriminant criteria for the provisionally tentative assignation to the genus Salgirella. Additionally, partial sectioning of fragmentary material has not conclusively revealed clear information about the pattern of the fibers concerning the shell microstructure.

This taxon can be unambiguously distinguished from its apparent congeneric relatives due to the consistently greater size, the markedly trapezoidal dorsal fold, and the numerous and more densely packed ribs. Comparable forms can be found only in the widely interpreted Rhynchonella gr. variabilis, which is considered a nomen dubium and should be revised.