1. ARCHOSAURS

2. 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

3. Skull is diapsid
There is an additional
fenestra – antorbital
fenestra – large
mandibular foramen
opening in the skull in
front of the eye that
distinguishes archosaurs

4. THECODONT
 Gave rise to all later archosaurs
 Named because their teeth are set in deep
sockets
 Stem archosaurs

5. PTEROSAURIA
The Winged Reptile

6. PTEROSAURS!
More commonly known as
PTERODACTYLS
First vertebrate to evolve
powered flight
ACTIVE AERIAL
LOCOMOTION
 Pterosaurs, birds and bats

7. RHAMPHORHYNCHOIDS
 Long tails and teeth

8. LATER PTERODACTYLOIDS
 Lacked a tail and teeth. Had projecting crest at
the back of the head.

9. TWO TEMPORAL FOSSAE/POST
ORBITAL FENESTRAE

10. I BELIEVE I CAN FLY 
Like birds, Pterosaurs had
pneumatic bones
Wings were more bat-like
Supported by an elongated 4th
finger
Long, hollow bones
Convergent evolution

12. DINOSAURS
RAAWRRR!

13. 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.

15. SAURISCHIA
Reptilian pelvis
Swift predatory carnivores
The three bones of the pelvis
– ilium, ischium, pubis–
radiate outward from the
center of the pelvis

18. ORNITHISCHIANS
 Pelvis similar of that of birds
 Herbivores. Lack teeth
 Some had horny beaks
 Some 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