Nannolytoceras

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Nannolytoceras
Temporal range: Bajocian–Bathonian[1]
Lytoceratidae - Nannolytoceras tripartitum.JPG
Fossil shells of Nannolytoceras tripartitum from Alpes-de-Haute-Provence, on display at Galerie de paléontologie et d'anatomie comparée in Paris
Scientific classification
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Nannolytoceras

Buckman, 1905

Nannolytoceras is an extinct genus of lytoceratid ammonite, family Lytoceratidae, with a stratigraphic range extending from the Bajocian age to Bathonian age (Medium Jurassic).[1]

Description[edit]

Shells of Nannolytoceras species reach a diameter of about 46–75 millimetres (1.8–3.0 in).[2][3] The shell is evolute, smooth, tubular to compressed, with a variable number of more or less regularly spaced deep constrictions.[3] The very thin ribs crossing the ventral region are barely visible. Umbilicus is relatively large. The suture line is of ammonitic type.[4] These cephalopods were fast-moving nektonic carnivores.[5]

Distribution[edit]

Fossils of species within this genus have been found in the Jurassic rocks of Italy, Spain[5] and Slovakia.[6]

References[edit]

  1. ^ a b Sepkoski, Jack (2002). "A compendium of fossil marine animal genera (Cephalopoda entry)". Bulletins of American Paleontology. 363: 1–560. Retrieved 2017-10-18.
  2. ^ Ammonites Nannolytoceras - Nannolytoceras tripartitum
  3. ^ a b Ammonites.fr
  4. ^ Redjaen
  5. ^ a b Paleobiology Database - Nannolytoceras. 2017-10-19.
  6. ^ Schlögl Ján (2001). Sedimentológia a biostratigrafia červených hľuznatých vápencov čorštýnskeho súvrstvia ("Ammonitico Rosso") v pieninskom bradlovom pásme.