Dino Notes #4     GEL 113

Theropods

Evolutionary Novelties:

1) broad exposure of the lachrymal bone on the skull roof

2) an extra fenestra in front of the antorbital fenestra

3) a sacrum comprising at least 5 vertebrae

4) a clawed hand

5) a bowed femur

6) a hind foot that was:

a) functional and long

b) compact, narrow and long

c) had three functional digits and a first digit separated from the rest of the foot

Other Theropod features:

Teeth - large, curved, compressed and serrated.

Large eyes

Largest and most sophisticated brains of any known dinosaurs

Possible kinetic skull

Ceratosaurs

Evolutionary Novelties:

Adapted for running.

a) sacrum totally fused and fused to ilium.

b) ankles and foot bones (tarsals, metatarsals ) fused

Gap between pre-maxillary and maxillary to fit large tooth from dentary bone (like sabretooth tiger).

Tetenurae "fused tails"

Includes all non-ceratosaurian theropods.

Evolutionary novelties:

1) reduction of teeth so that all are in front of orbit

2) No fang-like tooth in dentary ( and no notch between premaxillary and maxillary)

3) a second fenestra opened in front of eye

4) Modifications of hip for fast running

5) large "boot" on end of pubis in some

Carnosaurs

Evolutionary novelties:

1) an opening in lachyrymal bone

2) low spines on vertebrae of shoulder region

3) upwardly inclined head of femur

4) prongs on chevrons