Franconiasaurus is an extinct genus of basal plesiosauroid plesiosaurs from the Early Jurassic of Germany. The genus contains a single species, F. brevispinus, known from two well-preserved three-dime

Microcleididae is an extinct family of basal plesiosauroid plesiosaurs from the Early Jurassic of France, Germany, Portugal and the United Kingdom. Currently, the oldest and the most known microcleidi