Porpoceras

Porpoceras
Temporal range: Toarcian

[1]

Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: †Ammonoidea
Order: †Ammonitida
Family: †Dactylioceratidae
Subfamily: †Dactylioceratinae
Genus: †Porpoceras
Buckman, 1911
Type species
Ammonites vortex
Simpson, 1855
Species
  • P. vortex Simpson, 1855
  • P. verticosum Simpson, 1855
  • P. vorticellum Simpson, 1855
  • P. polare Frebold, 1929
  • P. spinatum Frebold, 1958
  • P. gigas Guex, 1973
  • P. planiventer Guex, 1972
  • P. pseudodesplacei Guex, 1972
  • P. crassicostatum Guex, 1972
  • P. beurleni Monestier, 1931
  • P. tenellissimum Monestier, 1931
Synonyms
  • Telodactylites Pinna & Levi-Setti, 1971
  • Platystrophites Levi-Setti & Pinna, 1971

Porpoceras is genus of ammonite that lived during the early and midde Toarcian stage of early Jurassic. Members of this genus existed from uppermost part of Serpentinum Zone to Variabilis Subzone.[2] Their fossils were found in Europe, Asia, North America and South America.[1]

Description

Ammonites belonging to this genus have evolute shells, with compressed to depressed whorl section. Flanks were slightly convex and venter has been low. Whorl section is subrectangular. Prorsiradiate ribs are strong and fibulate on inner whorls and tuberculate to spined on the place of ventrolateral shoulder.[3] It differs from Peronoceras by not having compressed whorl section and regular fibulation. Catacoeloceras is also similar, but it has regular ventrolateral tubercules and is missing fibulation.[1]

References

  1. 1 2 3 M. K. Howarth 2013. Treatise on Invertebrate Paleontology, Part L, Revised, Volume 3B, Chapter 4: Psiloceratoidea, Eoderoceratoidea, Hildoceratoidea.
  2. ↑ Jattiot, R., Fara, E., Brayard, A., & Vennin, E. (2016). Revised stratigraphic range of the Toarcian ammonite genus Porpoceras Buckman, 1911. Geodiversitas, 38(4), 505-513.
  3. ↑ KOVÁCS, Z. (2014). Toarcian Dactylioceratidae (Ammonitina) from the Gerecse Mts (Hungary). Hantkeniana, 9, 45-77.


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