This classical Tethyan Mediterranean specimen is very well preserved, showing much of his delicate suturing in intricate detail. Phylloceras were primitive ammonites with involute, laterally flattened shells.
They were smooth, with very little ornamentation, which led researchers to think of them resembling plant leaves and gave rise to their name, which means "leaf-horn."
They can be found in three regions that I know of. In the Jurassic of Italy near western Sicily's Rosso Ammonitico Formation, Lower Kimmeridgian fossiliferous beds of Monte Inici East and Castello Inici (38.0° N, 12.9° E: 26.7° N, 15.4° E) and in the Armine area, southeastern Toyama Prefecture, northern central Japan, roughly (36.5° N, 137.5° E: 43.6° N, 140.6° E).
