| Measurements | D mm | H/D | E/D | O/D | H/E |
|---|---|---|---|---|---|
| Neotype Casey 1961 | 35 | 0.53 | 0.29 | 0.20 | 1.83 |
| MPG 31117 Spath 1923 | 57 | 0.51 | 0.29 | 0.20 | 1.76 |
| Jaffré 2014 p.103 | 167 | 0.48 | 0.24 | 0.20 | 1.98 |
| CP-433 | 175 | 0.48 | 0.25 | 0.19 | 1.91 |
| CP-635 | 205 | 0.46 | 0.27 | 0.21 | 1.75 |
| Age | Origin |
|---|---|
|
Frécambault Sands formation H. benettianus zone, L. lyelli subzone Middle Albian |
Yonne France |
Description. Fully septate large specimen preserved in sandstone, with test remains on the figured face. Compressed and involute discoid shape, with whorls two-thirds covered and a narrow umbilicus with a subvertical low wall. Very high whorls, with flanks diverging slightly to the inner third, then converging towards a narrowly arched venter. On the view of aperture, it appears even higher due to oblique breakage. The internal mold is smooth. The test bears only falciform growth lines. The adjacent photo, with mouth direction on the right, shows the sutures except S and L1: the auxiliary elements are subrectangular, and almost aligned, giving a crenulated appearance.
Remarks. Personal discovery. Beudanticeras with the least incised suture. The macroconch sometimes has falciform constrictions on the internal mold, filled by weak ribs on the test: CP-635, a 205 mm half-turn from the same site, shows 7 of these appearing around 150 mm. Smaller, thicker forms with an identical suture are presumed microconchs, see their entry. Due to its compressed and smooth shape, this species from the subhilli, steinmanni, and benettianus zones was long confused with the later B. beudanti (cristatum and pricei zones), but the latter has a much more incised suture. B. laevigatum also resembles B. newtoni, known from the basal Albian to the steinmanni zone, which has a more complex suture. The two species coexist in the subhilli and steinmanni zones. A smooth Beudanticeras associated with Hoplites benettianus is always a laevigatum.