DINOSAURS

Introduction

Dinosaur means “terrible lizard”

Characteristics of dinosaurs:Very diverse

Herbivores and carnivores

Bipedal or quadrupedal

Terrestrial

Built nests and laid eggs

Varied skin types including scales, armor, feathers

Probably warm blooded

Dinosaurs

Lived 230 to 65 mya during the late Triassic to early Cretaceous Periods (including Jurassic)

Fossils have been found on every continent

Kingdom Animalia, Phylum Chordata, Class Reptilia

Flora and Fuana

Other animals alive at this time included: small shrew like mammals, insects, amphibians, reptiles, crocodiles, turtles, sharks, fish.

Plants: conifers, cycads, ginkgos, ferns

Orders of Dinosaurs

Saurischia and Ornithischia

Saurischia

Saurischia: “lizard hipped” survivors evolved into birds

Saurischia: Therapods

Therapods: Tyrannosaurus Rex and Velociraptor – bipedal, carnivorous, scales and feathers, includes modern birds

Saurischia: Sauropods

Sauropods: long necks, herbivores, quadrupedal, very large, weak teeth – Apatasaurous, Brachiosauris

Ornithischia

Ornithischia: “Bird hipped” (all died during extinction, no living descendents)

Ornithischia: Thyreophora

Thyreophora: “armored dinosaurs,” plates and spikes, herbivores, early Jurassic to Cretaceous, Ankylosaurus, Stegasaurus

Ornithischia: Ornithopods

Ornithopods: bipedal & quadrupedal, could chew, running grazers, herbivores of N. America - Iguanodon, Maiasaura

Ornithischia: Ceratopsians

Ceratopsians: horned-face, herbivores, beaked, large quadrupeds – Triceratops, Psittacosaurs

Pterosaurs

PterosaursAre not dinosaurs

Flying reptiles

First flying vertebrates

220 to 65 mya

Ranged in size from small to large

Many had hair, did not have feathers

Leathery wings

Marine ReptilesNot dinosaurs

PlesiosaurLong necksMarine predatorAir breather

MosasaurFierce aquatic predatorsBreathed airRelatives of snakes and monitor lizards

Marine Reptiles

IchthyosaurResembled dolphins

Air breathers

Phylogenic Tree

What happened to the dinosaurs?

Cretaceous Extinction65 mya

Mass extinction of plants and animals

Comet landed in Gulf of Mexico

All terrestrial (non-avian) dinosaurs died due to climate change and lack of food

Mammals, amphibians, and birds survived and thrived

Cold blooded reptiles survived

Birds evolved from dinosaurs

Prior to the Cretaceous Extinction, a small, light-weight Jurassic therapod began adapting to its environment

This animal survived the extinction, one early species was called Archaeopteryx