Breviconoteuthis Rieber, 1973
publication ID |
https://doi.org/ 10.1186/s13358-024-00316-7 |
DOI |
https://doi.org/10.5281/zenodo.12800835 |
persistent identifier |
https://treatment.plazi.org/id/03C16916-A344-FFFD-FF55-F8CCFAF2F9B5 |
treatment provided by |
Felipe |
scientific name |
Breviconoteuthis Rieber, 1973 |
status |
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Genus Breviconoteuthis Rieber, 1973
Type species: Atractites breviconus Reis, 1907 ; p. 148, pl. 3. fig. 3 by monotypy.
Diagnosis (after Fuchs & Donovan, 2018): Phragmocone very small to small, brevi- to slightly cyrtoconic, circular in cross section, apical angle 38°–40°; ratio of chamber length to diameter about 0.15; pro-ostracum three-lobed, longer than phragmocone, anterior median field rounded; siphuncle marginal; rostrum unknown.
Diagnosis (emended): Phragmocone very small to small sized, brevi- to slightly cyrtoconic, circular in cross section, apical angle 30–40°; ratio of chamber length to diameter between 0.15–0.25; pro-ostracum three-lobed, longer than phragmocone, anterior median field rounded; siphuncle marginal; rostrum unknown.
Stratigraphic and geographic occurrences: So far known only from the upper Anisian (Wettersteinkalk) of Austria (Tyrol), Switzerland ( Fuchs & Donovan, 2018) and Slovakia (Anisian—lower Illyrian; this paper).
Remarks: Breviconoteuthis and the slightly younger genus Phragmoteuthis Mojsisovics, 1882 (Carnian), the eponym of the order Phragmoteuthida , share a three-lobed proostracum morphology. Therefore, both genera can presently be distinguished only by phragmocone characters. The phragmocone of Breviconoteuthis displays a ventral curvature that is so far unknown in Phragmoteuthis .
The genus Zugmontites Reis, 1907 (upper Anisian) is based on a single specimen whose phragmocone parameters are close to those of Breviconoteuthis . Fuchs and Donovan (2018) interpreted Zugmontites as a putative phragmoteuthid owing to the absence of a proostracum. Due to the lack of available specimens, it can be presently not excluded that Zugmontites mojsisovicsi Reis, 1907 , the type spieces of Zugmontites , is identical to Breviconoteuthis breviconus . One feature delimiting the two type species might be the ventral curvature that seems to be more distinct in Breviconoteuthis than in Zugmontites .
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