Lecture 8: Ornithischian Dinosaurs, Pterosaurs, and the K-Pg Extinction

Flashcards covering key vocabulary and concepts from Lecture 8, including Ornithischian dinosaurs (ornithopods, ceratopsians, stegosaurs, ankylosaurs), pterosaurs, and the K-Pg extinction event.

Ornithischian Dinosaurs

Dinosaurs with a 'bird hip' pelvic bone pattern, first appearing in the late Triassic. They are herbivores comprising ornithopods, ceratopsians, stegosaurs, and ankylosaurs.

Ornithopod Features

From Jurassic to the latest Cretaceous, these dinosaurs featured bipedal locomotion, fused pubis and ischium, an efficient chewing mechanism, and probable cheeks.

Hadrosaurs

Abundant in the late Cretaceous, these dinosaurs had a modification of the maxilla and premaxilla to form a ‘bill’ and tooth ‘batteries’ for tough vegetation.

Ceratopsians

Dinosaurs that were firstly bipedal, latterly quadrupedal, with huge modified skulls featuring pronounced beaks and head frills/horns in late Cretaceous species. They also had neural spines for muscle attachments.

Thyreophora

Armoured ornithischians from the Mid Jurassic to late Cretaceous, divided into stegosaurs and ankylosaurs.

Stegosaurs

Armored dinosaurs known for bony dermal plates and tiny tubular skulls.

Ankylosaurs

Armored dinosaurs known for a huge amount of dermal bone, some with tail clubs.

Pterosaurs

Diapsids with uncertain origins among the Triassic archosaurs, considered the sister group to the dinosaurs. They consist of two groups: Rhamphorhynchoids and Pterodactyloids.

Rhamphorhynchoids

Pterosaurs from the late Triassic to latest Jurassic, characterized by long tails and teeth.

Pterodactyloids

Pterosaurs from the late Jurassic to latest Cretaceous, characterized by short tails and some toothless species.

Cretaceous-Paleogene (K-Pg) extinction event

The extinction event at the boundary of the Cretaceous and Paleogene periods, which led to the extinction of non-avian dinosaurs and pterosaurs.

K-Pg Extinction Event: Extinctions and Survivors

Non-avian dinosaurs, pterosaurs, plesiosaurs, and ammonites became extinct. Crocodiles, turtles, lizards, snakes, amphibians, placental mammals, most fish, and most plants and invertebrates survived.