Sonninites felix Buckman, 1923 [M]

(Fig. 9 E-G)

Sonninites felix (in pars) Buckman, 1923: T.A. 5, pl. 428A (HT), non pl. 428B (corresponds to Sonninia corrugata (Sowerby, 1824)).

Sonninia aff. felix – Gillet 1937: 35, pl. 4, fig. 4.

Sonninia felix – Fernández-López 1985: 54, pl. 8, figs 2, 3.

Sonninia [“ Sonninites ”] aff. felix – Dietze et al. 2009: 25, pl. 8, figs 1-3, non fig. 4, pl. 11, fig. 3.

Sonninia [“ Sonninites ”] felix – Dietze et al. 2011a: 213, pl. 6, fig. 6.

Sonninia (Sonninites) felix [M] – Chandler 2019: 777, fig. 16, b1-b2.

? Sonninia carinodisca – Dietze et al. 2020: 68, pl. 15, fig. 1.

MATERIAL EXAMINED. — JAC3.83.1, JAC3.91.2, JAC3’.4.30, JAC3’.10.1, JAC3’.13.1, JAC4.68.3, JAC4. R.21, JAC20. R.1, JAC21.12.8, JAC21.12.9, JAC21.13.1, JAC21.13.2, JAC21.13.4, JAC21.14.1, JAC21.15.3, JAC21.16.1, JAC21.17.2, JAC21.17.3, JAC21.17.4, JAC21.18.1, JAC21.18.2 and JAC22.(70-80).3.

MEASUREMENTS. — See Table 9.

DESCRIPTION

Large discoidal shells of moderately involute coiling, with intermediate whorls more involute than the internal or external ones. Inner whorls have a subrectangular whorl section. The intermediate ones have a compressed ogival (oval) section, with the maximum width located near the middle part of the flanks, which are weakly convex. The umbilical wall is low, subvertical or strongly sloping and the ventral region is ogival, with a narrow, high and hollow keel. Ornamentation varies throughout ontogeny. In the internal whorls with furcate ribs, the splitting point of the ribs coincides with a thickening near the umbilical edge, and subsequently the division point gradually becomes more external. In the intermediate whorls, the ribbing is subradial or slightly sigmoid, bending forward on the outer side of the flanks, irregular in relief, fasciculate in two or three at variable height in the lower half of the flanks. Simple ribs (c. 40-50 mm in diameter) are common, slightly flexuous, rectiradiate, and prominent in the inner half of the flanks, but weaker and curved forward in the outer half. In addition, some weaker intercalatory ribs appear, and finally, on the end portion of the PH and in the BC of adult specimens, the ribbing is extremely attenuated, or even absent, and the ornamentation diminishes to weak undulations and growth lines or striae. The septal suture is relatively complex, with highly branched L and U 2 that are wide and not deep, whereas the E-L and L-U 2 saddles are rather narrow, and the umbilical lobes are weakly retracted.

REMARKS

Sonninites celans Buckman, 1924 (Buckman 1924: T.A. 5, pl. 461) is more involute, mainly in intermediate whorls, and has more radial ribbing. “ Dundryites ” albidus Buckman and “ Sonninites ” simulans Buckman (here considered synonymous and ascribed to the genus Witchellia) have similar ribbing on median and external whorls, but have no tuberculate inner whorls and a rectangular whorl section, with a tabulate venter. Sonninia (S.) corrugata (Sowerby, 1824) has similar inner whorls, but is smaller, has more persistent ribbing, and is slightly more evolute. Dorsetensia subtecta Buckman, 1892 (in Buckman 1887 -1907: 309, pl. 55, only pl. 54, figs 3-5, here included as synonymous of Dorsetensia liostraca) has quite similar coiling and ornamentation on the outer whorls, but its ribbing sharply differs on inner whorls, it lacks tubercles, and its umbilical wall is not subvertical.

DISTRIBUTION

According to Chandler et al. (2006: 369) the HT of Sonninites felix (Buckman, 1923) comes from the Sauzei (Propinquans) Zone, Patella Subzone, Bj-11a horizon, Inferior Oolite at South Main Road Quarry, Dundry, Avon (England). Recently, Dr R. B. Chandler (pers. communication) indicated the exact stratigraphic horizon from which the HT of So. felix came (i.e. the Stephanoceras rhytum horizon, Bj-12, top of the Sauzei = Propinquans Zone). In England, this species is present also in the horizon Bj-11b (Dietze et al. 2011a). In Germany, So. felix and So. aff. felix occur in the Macrum horizon, in the upper part of the Propinquans (Sauzei) Zone (Dietze et al. 2009, 2011a, b). In La Baume (Castellane area, SE France), So. cf. felix occurs in the Propinquans Zone (De Baets et al. 2008). In the Iberian Cordillera (Spain), the species is common in the lower and middle parts of the Sauzei (Propinquans) Zone (Fernández-López 1985). In the Subbetic, it occurs in the Propinquans Zone, being especially abundant in Sierra de Alta Coloma area (sections, JAC3, JAC3’, JAC4, JAC11, JAC21 and JAC.22; Jaén Province).