Phylloceras is an extinct genus of ammonoid cephalopods belonging to the family Phylloceratidae. These nektonic carnivores lived from Early Jurassic (Hettangian age) to Late Cretaceous (Maastrichtian age) (from 201.30 to 66.043 Ma). Description Shells of Phylloceras can reach a diameter of about , with a maximum of about . These primitive ammonites had an involute, laterally flattened shell with a regular shell opening. They were almost smooth and the ornamentation was virtually absent or, at most, represented by simple growth lines barely visible. The striking sinuous suture lines were characteristic of this genus. They are reminiscent, in some ways, of the leaves of plants (hence the name Phylloceras, which means " leaf-horn"). Distribution Fossils of species within this genus have been found all over the world, particularly in Western Europe. References Cyril Walker & David Ward (1993) - Fossielen: Sesam Natuur Handboeken, Bosch & Keuning, Baarn. Jurassic ammonites Cretaceous ammonites Ammonites of Europe Hettangian genus first appearances Sinemurian genera Pliensbachian genera Toarcian genera Aalenian genera Bajocian genera Bathonian genera Callovian genera Oxfordian genera Kimmeridgian genera Tithonian genera Berriasian genera Valanginian genera Hauterivian genera Barremian genera Aptian genera Albian genera Cenomanian genera Turonian genera Coniacian genera Santonian genera Campanian genera Maastrichtian genus extinctions Ammonites of South America Paja Formation Hasle Formation