Sonninia (Euhoploceras) Buckman 1913
Bibliographic record
Abstract
Subgenus Sonninia (Euhoploceras)Buckman, 1913 [M] & [m] Sonninia (Euhoploceras) Buckman, 1913: 4. ? Stiphromorphites Buckman, 1923 [M]: pl. 398. — Type species: S. nodatipinguis Buckman, 1923 (OD). Sherbonites Buckman, 1923 [M]: pl. 411. — Type species: S. projectifer Buckman, 1923 (OD). Nannoceras Buckman, 1923 [m]: pl. 445, n. syn. — Type species: N. nannomorphum Buckman, 1923 (OD). TYPE SPECIES. — Sonninia acanthodes Buckman, 1889 (Buckman 1889: 658 [OD]); HT figured in Buckman (1892: pl. 60, pl. 63, fig. 1). DESCRIPTION Macroconchs evolute to moderately involute with rectangular (sometimes almost square) to ovate, slightly compressed whorl sections. The venter is subtabulate, often slightly bisulcate and possesses a low hollow keel persisting to end of the BC. The inner whorls have weak primary ribs and many shells have well-developed tubercles or spines. The length of the spinose/ tuberculate stage varies widely and it is not uncommon to find specimens that retain strong ribbing beyond the end of the PH. The BC commonly has single or, more rarely, some bifurcate ribs, which extend as far as the peristome. In others, tubercles give way to ribs, which progressively fade, the BC becoming striated or completely smooth. Conversely, many lack strong ornamentation throughout ontogeny occasionally with tiny spines present only on the earliest inner whorls. Secondary ribs range from strong to weak. The septal suture is relatively complex, with a ramified deep L, and slightly retracted U2-U5 lobes. Complete macroconchs have simple, only very slightly constricted peristomes, which appear to be rather weak and are consequently rarely preserved. The microconchs (Nannoceras) are much smaller, with more persistent ribbing and spatulate lateral lappets. REMARKS According to some authors (Buckman 1928, T.A. 7: 13; Fernández-López 1985: 94), Nannoceras probably represents the dimorphous microconch of S. (Euhoploceras). Actually, other authors (Dietze et al. 2005: 59; Dietze et al. 2007: 16, 2011a: 217; Chandler et al. 2006: 370; Howarth 2013 in the Treatise) have suggested that Fontannesia Buckman [M] and the lappeted Nannoceras Buckman [m] constitute a dimorphous pair, which in turn are the most plausible ancestors of Witchellia [M] – Pelekodites [m]. Chandler (2019: 181, fig. 8e-g) figured three specimens of S. (Euhoploceras) [m], which are lappeted and have strong ribbing, and two have tuberculate inner whorls, which undoubtedly correspond to “ Nannoceras ”. Dr. R.B. Chandler confirmed to me (personal communication, March 2021) that, as Fernández-López (1985) had indicated, Nannoceras [m] is the dimorphic pair of S. (Euploceras) [M] and he generously sent me some plaster casts and photographs of typical Nannoceras from the upper Aalenian (Concavum Zone, Limitatum Subzone) and Lower Bajocian (Discites Zone) of Dorset (S England), which stratigraphically coexist with S. (Euhoploceras). DISTRIBUTION In agreement with the Treatise by Howarth (2013: 116), the present study concludes that the stratigraphic range of S. (Euhoploceras) extends throughout the upper Aalenian (Concavum Zone) to the lower Bajocian (Laeviuscula Zone) of Europe, North Africa (Atlas Ranges), Arabian Peninsula, China (Tibet), western Australia, Canada (British Columbia, Alberta), United States (Alaska, Oregon, California), Chile, and Argentina.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.017 | 0.005 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".