Nannolytoceras
| Nannolytoceras Temporal range: Medium Jurassic, 171.6–168.4 Ma | |
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| Fossil shells of Nannolytoceras tripartitum from Alpes-de-Haute-Provence, on display at Galerie de paléontologie et d'anatomie comparée in Paris | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | Ammonoidea |
| Order: | Lytoceratida |
| Suborder: | Lytoceratina |
| Family: | Nannolytoceratidae |
| Genus: | 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).[2]
Description
Shells of Nannolytoceras species reach a diameter of about 46–75 millimetres (1.8–3.0 in).[3][4] The shell is evolute, smooth, tubular to compressed, with a variable number of more or less regularly spaced deep constrictions.[4] The very thin ribs crossing the ventral region are barely visible. Umbilicus is relatively large. The suture line is of ammonitic type.[5] These cephalopods were fast-moving nektonic carnivores.[1]
Distribution
Fossils of species within this genus have been found in the Jurassic rocks of Italy and Spain.[1]
References
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