Sonninia (Sonninia) propinquans
Creators: name: Sandoval, José
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Cephalopoda
Ammonoidea
Sonniniidae
Sonninia
Sonninia propinquans

description: Sonninia (Sonninia) propinquans (Bayle, 1878) [M] (Fig. 7 A-D)
Waagenia propinquans Bayle, 1878: pl. 84, fig. 1 (LT designated by Gillet 1937: 29) to fig. 6.
Sonninia sowerbyi – Douvillé 1885: 20, pl. 1, fig. 1.
Sonninia propinquans – Douvillé 1885: 20, pl. 1, fig. 2. — Riche & Roman 1921: 136, pl. 6, fig. 1. — Buckman 1922: T.A. 4, pl. 298. — Pavia 1983: pl. 5, fig. 1. — Contini 1994: 104, pl. 39, figs 1ac, 2. — Sandoval 1994: 206, pl. 1, fig. 3. — Sadki 1996: 176, pl. 4, fig. 11. — Rioult et al. 1997: 104, pl. 14, fig. 4. — Seyed-Emami et al. 2000: 257, fig. 3/5. — Dietze et al. 2009: 30, pl. 9, fig. 2, pl. 10, fig. 7. — Metodiev & Tsvetkova 2014: 31, figs 3.1-5. — Chandler & Whicher 2015: pl. 14, fig. 1. — Dietze et al. 2020: 64, pl. 6, fig. 5, pl. 12, fig. 2, pl. 13, fig. 1.
Sonninia cf. propinquans – Fernández-López 1985: 45, text-fig. 4f, pl. 8, fig. 2. — Henriques et al. 1985: 104, pl. 1, figs 1, 2.
Sonninia ex gr. propinquans – Metodiev 2019: 19, figs e, f.
MATERIAL EXAMINED. — JAC6.40.1, JAC11.8.8, JAC11. R.56, JAC11. R.57, JAC11. R.58, JAC11. R.59, JAC11. R.60, JAC13. R.1, JAC21.16.4 and JAC21.16.5.
MEASUREMENTS. — See Table 1.
DESCRIPTION
Medium-sized macroconchs, relatively evolute, but with quite variable coiling (U/D varying from 0.31 to 0.42 in Subbetic specimens), being somewhat more evolute in the inner whorls than in the outer ones. The whorl section varies throughout ontogeny, as subcircular to subrectangular or ovate shape in the inner whorls becoming compressed ogival in the outer ones. The oblique to rounded umbilical wall merges with the rounded umbilical edge, and the flanks, gently convex, converge to the venter, which supports a moderately high hollow keel. Ornamentation varies throughout ontogeny and among specimens. Usually, inner whorls have subradial ribs that during ontogenetic development become uneven in relief and, from a variable diameter on the more prominent ribs, rounded tuber - cles are differentiated, which are located near the line of involution. In the intermediate whorls, the tubercles are thicker and more prominent than in the internal ones, and are located in the middle of flanks, where two or, more frequently, three secondary ribs generally arise. Between the tuberculate ribs, one to four less prominent simple ribs can usually be found. From the ventrolateral edge, ribs are strongly curved forward and, although quickly fading, extend nearly to the keel. The septal suture is not preserved in the specimens analysed.
REMARKS
Like other species of S. (Sonninia) and S. (Euhoploceras) (see Sandoval & Chandler 2000; Dietze et al. 2005), S. (S.) propinquans has wide intraspecific variability, which is noticeable in the degree of coiling, changes in the type of section throughout ontogeny, and changes in ornamentation such as the type of ribbing and, especially, length of the tuberculate stage. The most similar species is S. (S.) patella (Waagen, 1867), which is more involute, has a more compressed whorl section, mainly in the BC of the adult stages, and has a shorter tuberculate stage, with less developed tubercles.
DISTRIBUTION
The type horizon of the type species of S. (S.) propinquans [Waagenia propinquans Bayle, 1878] lies in the Sauzei Zone in les Moutiers, near Caen, France (Bayle 1878: pl. 84; Gillet 1937: 29; Contini 1994: 104; Dietze et al. 2005: 23, 2009: 30). The species has been mentioned in numerous localities among the characteristic fossils of the Propinquans Zone in Western Europe. With the same stratigraphic range, it occurs in Morocco (Sadki 1994, 1996) and Iran (Seyed-Emami 1988; Seyed-Emami et al. 2000). In the Subbetic, the species appears in the Propinquans Zone (Patella Subzone) from several Median and External Subbetic localities.
description: Published as part of Sandoval, José, 2022, Sonniniidae Ammonitina, Middle Jurassic from Southern Spain: taxonomic, biostratigraphical and palaeobiogeographical analysis, pp. 801-851 in Geodiversitas 44 (27) on pages 810-812, DOI: 10.5252/geodiversitas2022v44a27, http://zenodo.org/record/7150329