Nannolytoceras

{{Short description|Genus of molluscs (fossil)}}

{{italic title}}

{{Taxobox

| name = Nannolytoceras

| fossil_range = {{fossil range|Bajocian|Bathonian|ref=}}

| image = Lytoceratidae - Nannolytoceras tripartitum.JPG

| image_caption = Fossil shells of Nannolytoceras tripartitum from Alpes-de-Haute-Provence, on display at Galerie de paléontologie et d'anatomie comparée in Paris

| regnum = Animalia

| phylum = Mollusca

| classis = Cephalopoda

| subclassis = Ammonoidea

| ordo = Lytoceratida

| subordo = Lytoceratina

| familia = Nannolytoceratidae

| genus = Nannolytoceras

| genus_authority = 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).{{cite journal |last=Sepkoski |first=Jack |title=A compendium of fossil marine animal genera (Cephalopoda entry) |journal=Bulletins of American Paleontology |volume = 363 |pages = 1–560 |year=2002 |url=http://strata.geology.wisc.edu/jack/showgenera.php?taxon=231&rank=class | accessdate=2017-10-18}}

Description

Shells of Nannolytoceras species reach a diameter of about {{convert|46|-|75|mm}}.[http://jsdammonites.fr/381.html Ammonites Nannolytoceras - Nannolytoceras tripartitum][http://www.ammonites.fr/Fiches/0620.htm Ammonites.fr] The shell is evolute, smooth, tubular to compressed, with a variable number of more or less regularly spaced deep constrictions. The very thin ribs crossing the ventral region are barely visible. Umbilicus is relatively large. The suture line is of ammonitic type.[http://www.redjaen.es/francis/?m=c&o=29577 Redjaen] These cephalopods were fast-moving nektonic carnivores.[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=15222 Paleobiology Database - Nannolytoceras]. 2017-10-19.

Distribution

Fossils of species within this genus have been found in the Jurassic rocks of Italy, Spain, Slovakia,Schlögl Ján (2001). Sedimentológia a biostratigrafia červených hľuznatých vápencov čorštýnskeho súvrstvia ("Ammonitico Rosso") v pieninskom bradlovom pásme.

and France.{{Cite journal|last=Pavia|first=Giulio|last2=Fernández-López|first2=Sixto|last3=Mangold|first3=Charles|date=2008-07-01|title=Ammonoid succession at the Bajocian-Bathonian transition in the Bas Auran area, Digne District, South-East France|url=https://www.researchgate.net/publication/236620505_Ammonoid_succession_at_the_Bajocian-Bathonian_transition_in_the_Bas_Auran_area_Digne_District_South-East_France|journal=Rivista Italiana di Paleontologia e Stratigrafia|volume=114|pages=287–311.|doi=10.13130/2039-4942/5903}}

References