Witchellia romanoides
Creators: name: Sandoval, José
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Cephalopoda
Ammonoidea
Sonniniidae
Witchellia
Witchellia romanoides

description: Witchellia romanoides (Douvillé, 1885) [M] (Fig. 10 F-K)
Ludwigia romanoides Douvillé, 1885: 28, fig. 9, pl. 3, figs 3, 4 (LT designed by Dietze et al. 2007).
Witchellia (W.) romanoides – Parsons 1979: pl. 1, figs 3, 5.
Witchellia sp. – Pavia 1983: pl. 4, fig. 3.
Witchellia romanoides – Fernández-López 1985: 72, text-figs 8F, 8G, pl. 6, figs 5, 6. — Sadki 1996: 172, pl. 4, fig. 3. — Ohmert 2004: 56, pl. 15, figs 5, 6.
Witchellia romanoides [M] – Dietze et al. 2007: 10, pl. 4, figs 1-5.
Witchellia pseudoromanoides – Metodiev 2019: 15, figs 5c-e.
Witchellia patefactor – Metodiev 2019: 15, figs 5g, h.
MATERIAL EXAMINED. — JST.87.1, JST.93.1, JST.93.2, JST.93.3, JST.93.4, JST.93.5, JST.95.1, JAC3. R.5, JAC3.20.1 to JAC3.20.9, JAC3.21.1, JAC3.21.2, JAC3.23.1 JAC3.31.5, JAC3. R.5, JAC4.15.2, JAC4.15.3, JAC4.17.2, JAC4.30.1, JAC4.32.3, JAC4.32.4, JAC4.33.1, JAC4.33.2, JAC11.4.11 to JAC11.4.14, JAC11.4.16 to JAC11.4.26, JAC11. R.8, JAC11. R.11, JAC11. R.13, JAC11. R.14, JAC11. R.20, JAC11. R.21, JAC11. R.25, JAC11. R.53, JAC13.34.10, JAC13.34.11, JAC13. R.26, JAC13. R.27, JAC22.5.8, JAC22.5.22, JAC22.16.1, JAC22.16.2, JAC22.16.3, JAC22.16.4, JAC22.16.8, JAC22.24.2, JAC22.28.4, JAC22.28.5, JAC22.30.4, JAC22.33.1, JAC22.41.1, JVM.61, JVM.62, JVM.63, JVM.64, JVM.65, JFA.12.1, JFA.14.2, JFA.14.3, B.10.1, JFB. R.1 and TT.7.
MEASUREMENTS. — See Table 13.
DESCRIPTION
Medium-sized planulate macroconchs,compressed,with medium to moderately involute coiling (O/D of the Subbetic adult specimens varying between 0.29 and 0.38). The whorl section is almost rectangular, with a sloping umbilical wall and rounded umbilical edge,flattened flanks,narrow ventral region, tabulated, with a thin and prominent keel, without lateral grooves on the middle and outer whorls.The innermost whorls are smooth and have no tuberculate stage. The inner and intermediate whorls present weak flexuous, subradial ribs, strongly projecting forward in the ventral region,which during ontogenetic development are usually successively divided,fasciculate, grouped at the umbilical border and simple, but this varies according to the specimen. The outer whorls may become almost smooth, with flexuous growth striae arranged in bundles. The septal suture is relatively simple, with L wide and short.
REMARKS
The rectangular whorl section with a tabulate venter lacking sulci, relatively evolute coiling, and weak ribbing, which can almost disappear at the adult stages, distinguishes W. romanoides from other Witchellia species. The morphologically most similar species is “ Hyalinites ” hyalinus Buckman, 1924 (Buckman 1924: T.A. 5: pl. 519, HT), for which only the HT is known with a septate PH (92 mm in diameter), which is much larger than any known specimen of W. romanoides. According to Buckman (1924), this form comes from the Sauzei Zone of Clatcombe, Sandford Lane, Sherborne (England), and is therefore stratigraphically substantially later that W. romanoides. W. pseudoromanoides Dietze, Chandler & Schweigert, 2003, probably a descendent of the W. romanoides group (Dietze et al. 2003: 13), is another similar species but is more involute and has more coarsely ribbed ornamentation.
DISTRIBUTION
The stratigraphic position of the type of W. romanoides is not clear, but it is possibly from the Ovale Zone of the Vallée de Valaury, southern France (Dietze et al. 2007). The specimen figured by Pavia (1983) confirms this stratigraphical range. The species has been frequently cited in the Ovale and Laeviuscula zones. In England it extends from the Ovale Zone to the Laeviuscula Zone, Trigonalis Subzone (Parsons 1974, 1977, 1979; Callomon & Chandler 1990; Dietze et al. 2003, 2007; Chandler et al. 2006). A comparable stratigraphic range is occupied in Germany (Ohmert 2004), Morocco (Sadki 1994, 1996), Bulgaria (Metodiev 2019), and Spain (the Iberian range; Fernández-López 1985). In the Subbetic domain, W. romanoides appears in diverse localities, being especially abundant in the Ovale Zone and Laeviuscula Zone (Trigonalis Subzone) of Sierra de Alta Coloma area (Granada and Jaén Provinces).
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 826-827, DOI: 10.5252/geodiversitas2022v44a27, http://zenodo.org/record/7150329