Fossil and life reconstruction of Syllipsimopodi bideni （Image source：Christopher D. Whalen & Neil H. Landman， CC BY-SA 4.0 ） Age Carboniferous（Serpukhovian） 330 Ma Taxonomy Kingdom: Animalia Phylum: Mollusca Class: Cephalopoda Genus: Syllipsimopodi Species: Syllipsimopodi bideni Morphological description Syllipsimopodi bideni was a small cephalopod, measuring approximately 12 cm in total length. Its body was torpedo-shaped, with a roughly triangular gladius-like internal

Reconstruction of Hexameroceras panderi （Image source：Nix Illustration， CC BY-NC 4.0 ） Age Silurian（Gorstian-Ludfordian） 425-423 Ma Taxonomy Kingdom: Animalia Phylum: Mollusca Class: Cephalopoda Subclass: Nautiloidea Order: Oncocerida Family: Hemiphragmoceratidae Genus: Hexameroceras Species: Hexameroceras panderi Morphological description Hexameroceras panderi possessed a downward-curving, teardrop-shaped shell, reaching approximately 5 cm in length. Some fossil specimens

Lateral and frontal views of Gryphaea arcuata （Image source：H. Zell， CC BY-SA 3.0 ） Age Jurassic（Hettangian-Pliensbachian） 119.6-33.9 Ma Taxonomy Kingdom: Animalia Phylum: Mollusca Class: Bivalvia Order: Ostreida Family: Gryphaeidae Genus: Gryphaea Species: Gryphaea arcuata Morphological description The left valve (the larger shell) of Gryphaea arcuata is strongly curved and coils inward, resembling a crescent or an arched "long toenail." The right valve is smaller and rel