Barroisiceras
{{Short description|Genus of molluscs (fossil)}}
{{Automatic taxobox
|fossil_range = {{fossil range|Coniacian|ref=}}
|image = Collignoniceratidae - Barroisiceras species.JPG
|image_caption = Fossil of Barroisiceras species. Coniacian of Madagascar
|taxon = Barroisiceras
|authority = de Grossouvre, 1894
|subdivision_ranks = Subgenera
|subdivision =
- Barroisiceras (Alstadenites)
- Barroisiceras (Barroisiceras)
- Barroisiceras (Texasia)
}}
Barroisiceras is an acanthoceratacean ammonite from the Upper Cretaceous, Coniacian,{{cite web
| last = Sepkoski| first = Jack| title= Sepkoski's Online Genus Database|author-link =| year = 2002| url = http://strata.geology.wisc.edu/jack/showgenera.php?taxon=231&rank=class| accessdate = 2014-05-28 }} included in the family Collignoniceratidae.
Diagnosis
The shell of Barroisiceras is rather involute, coiled such that the outer whorl embraces much of the previous, and is generally compressed. Whorls are high with a strong crenulate keel and sparse umbilical tubercles that develop into pairs of commonly flat ribs.
Taxonomy
Barroisiceras is divided two subgenera, Barroisiceras (Barroisiceras) and Barroisiceras (Texasia),with Alstadenites sometimes added as a third, Barroisiceras (Alstadenites).
B. (Barroiciceras) is moderately involute and the suture is rather simple. B. (Texasia) is more evolute and has a distinctly eccentric umbilicus and more complex suture.
Distribution
References
;Notes
{{Reflist}}
;Bibliography
- Arkell et al., 1957. Mesozoic Ammonoidea Treatise on Invertebrate Paleontology part L, Ammonoidea.
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