GEOL 008 Lecture Notes - Lecture 2: Iguanodon, Ankylosauria, Yolk Sac
Document Summary
Walked on four legs or sprint on two (strategy of survival) First appear in the late middle jurassic and persist until the end of the cretaceous. Clades (all lineage of said dinosaurs, branch on the tree) Are the most numerous clade of ornithischians. First (basal;very first ancestor) ornithopod- hypsilophodon hypsilopho-tooth . Ornithopoda (divided into two main branches: iguanodontia, styracostema. Split took place shortly after the hypsilophodon (mid-jurassic) Iguanodontia (closer related to the original or basil hypsilophodon) Mid jurassic to end of the cretaceous. Most abundant large animals in the cretaceous (displacing sauropods;long necks) Much larger size: 6m or more (48+ feet) Metacarpals ii-iv turned into metatarsals (hoof-like) fingers turned stronger . Metacarpal v opposable (turned thumb to spike) Europe, north america, asia, and northern africa. Syracosterna: iguanodon (the first dinosaur ever found in late 1840"s) Found in asia, europe, and north america: hadrosauridae. Range: europe, south america, asia, north america, and antarctica.
