ARCHOSAURS

Dominant land vertebrates during the Mesozoic

Display a trend towards bipedalism – 2 footed locomotion

Forelimbs tend to be reduced and hindlimbs are drawn under the body to become the major weight bearing and locomotor appendages

Skull is diapsidThere is an additional fenestra – antorbital fenestra – large mandibular foramen opening in the skull in front of the eye that distinguishes archosaurs

THECODONT

Gave rise to all later archosaurs Named because their teeth are set in deep

sockets Stem archosaurs

PTEROSAURIAThe Winged Reptile

PTEROSAURS!

More commonly known as PTERODACTYLS

First vertebrate to evolve powered flight

ACTIVE AERIAL LOCOMOTIONPterosaurs, birds and bats

RHAMPHORHYNCHOIDSLong tails and teeth

LATER PTERODACTYLOIDS Lacked a tail and teeth. Had projecting crest

at the back of the head.

TWO TEMPORAL FOSSAE/POST ORBITAL FENESTRAE

I BELIEVE I CAN FLY

Like birds, Pterosaurs had pneumatic bones

Wings were more bat-likeSupported by an elongated 4th finger

Long, hollow bonesConvergent evolution

DINOSAURSRAAWRRR!

DINOSAURS!One of the most successful groups of

animals (in terms of longevity) that have ever lived, evolved into many diverse sizes and shapes, with many equally diverse modes of living.

Contains two major groups of dinosaurs: the Ornithischia, or "bird-hipped" dinosaurs, and the Saurischia, or "lizard-hipped" dinosaurs.

SAURISCHIAReptilian pelvisSwift predatory carnivoresThe three bones of the pelvis – ilium, ischium, pubis– radiate outward from the center of the pelvis

ORNITHISCHIANSPelvis similar of that of birdsHerbivores. Lack teethSome had horny beaksSome small unidentified bipedal

ornithischian is thought to have given rise to birds

The ischium and part of the pubis lie parallel and project backward toward the tail