Porpoceras, Buckman, 1911
publication ID |
https://doi.org/ 10.5252/g2016n4a3 |
publication LSID |
urn:lsid:zoobank.org:pub:BC8394F4-9DF1-458A-B9A1-4293D82962EE |
persistent identifier |
https://treatment.plazi.org/id/504C4F13-FFC8-FFDB-7DA2-9F33FD54FB20 |
treatment provided by |
Felipe |
scientific name |
Porpoceras |
status |
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Porpoceras View in CoL gr. vortex ( Simpson, 1855) - verticosum Buckman, 1914
( Figs 4 View FIG B-H; 5)
Ammonites vortex Simpson, 1855: 60 View in CoL .
Porpoceras vortex View in CoL – Buckman 1911: pl. 29A. — Géczy & Szente 2007: pl. 8, fig. 4.
Porpoceras verticosum Buckman, 1914 : pl. 91.
Porpoceras gr. vortex - verticosum – Rulleau et al. 2013: 101, pl. 29, fig. 2; pl. 30, figs 1, 2; pl. 31, figs 1, 3, 5; pl. 32, figs 1, 3-6; pl. 33, figs 1, 2; pl. 34, fig. 1.
Porpoceras vortex View in CoL – Kovàcs 2014: 50, pl. 2, figs 2, 7; pl. 4, fig. 5. DESCRIPTION
Very evolute shell with a cadicone whorl section on inner whorls, becoming quadratic to depressed on mature whorls. Every two, three or four primary ribs, one primary rib bears a ventro-lateral tubercle. Ribs are often grouped by two on the same tubercle. This ornamentation is constant throughout ontogeny. Each tubercle bears a very developed spine leaning on the following whorl and not visible on internal molds. Suture lines not visible on the specimens from the Airvault quarry.
MEASUREMENTS
See Table 1. View TABLE
STRATIGRAPHIC AND PALAEOGEOGRAPHICAL OCCURRENCES From the uppermost part of the Serpentinum Zone (?) to the Variabilis Subzone; found in NW Europe, Siberia, Spitsbergen, North and South America.
DISCUSSION
According to Rulleau et al. (2013), it is extremely difficult to distinguish P. vortex from P. verticosum , even with a large number of specimens. They therefore decided to include these two species within the same group and we concur with this taxonomic opinion. Porpoceras differs from Catacoeloceras and Mucrodactylites by its well-developed ventro-lateral tubercles and ribs generally grouped by two on the same tubercle. The resembling genus Peronoceras is older and does not exhibit tubercles on inner whorls ( Rulleau et al. 2013).
Genus | Species | Specimen | D | H | W | U | H/D | U/D | Remarks |
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Porpoceras | vortex-verticosum | UBGD 279076 | 59 | 13.3 | – | 34.8 | 0.23 | 0.59 | – |
Porpoceras | vortex-verticosum | UBGD 279077 | 57.3 | 11.5 | – | 35.2 | 0.20 | 0.61 | – |
Porpoceras | vortex-verticosum | UBGD 279075 | 74.7 | 18.7 | – | 43.5 | 0.25 | 0.58 | – |
Porpoceras | vortex-verticosum | 1665 F-2; Rulleau et al. (2013: pl. 32, fig. 1) | 78 | 17 | 20.5 | 47 | 0.22 | 0.60 | – |
Porpoceras | vortex | WM 153a; Buckman (1911: pl. 29A) | 83 | 15 | 26 | 53 | 0.18 | 0.64 | Holotype |
Porpoceras | verticosum | WM 220a; Buckman (1914: pl. 91) | 71 | 15 | 18.5 | 43 | 0.21 | 0.61 | Holotype |
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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Porpoceras
Jattiot, Romain, Fara, Emmanuel, Brayard, Arnaud & Vennin, Emmanuelle 2016 |
Porpoceras vortex
KOVACS A. 2014: 50 |
vortex
SIMPSON M. 1855: 60 |