Chapter 15 Outline
GEOGRAPHIC DISTRIBUTION
- DINOSAURS HAVE BEEN FOUND ON ALL CONTINENTS
- LATE TRIASSIC THROUGH LATE CRETACEOUS DISTRIBUTION FOR ALL CONTINENTS
EXCEPT AUSTRALIA AND ANTARCTICA
- Early Jurassic and Late Jurassic dinosaurs have yet to be found
in Australia
- Only Early Jurassic and Late Cretaceous dinosaurs have been found
in Antarctica so far
- ENDEMISM
- DISTINCTIVE CHARACTERISTICS RESULTING FROM ISOLATION
- A region populated by distinct faunas unique to it shows high endemism
- Low endemism results when faunal interchange is high, as early in
the Mesozoic Era when Pangea was in existence
- THE LATE TRIASSIC AND EARLY JURASSIC WERE TIMES OF LOW ENDEMISM
- THE LATE JURASSIC AND EARLY CRETACEOUS WERE TIMES OF INCREASING ENDEMISM
- DINOSAUR ENDEMISM REACHED AN ALL-TIME HIGH DURING THE LATE CRETACEOUS
- Continents widely separated
- Strong similarities between North American and Asian dinosaur families
- Co-evolution of dinosaurs and plants, particularly flowering
plants (angiosperms) during the Late Cretaceous
- TEMPORAL DISTRIBUTION
- MANY DINOSAUR GENERA LIVED 4-8 MILLION YEARS
- PRESENTING FAUNAS IN TIME INTERVALS LASTING FROM 13 MILLION YEARS (LATE
JURASSIC) TO 47 MILLION YEARS (EARLY CRETACEOUS) [AVERAGE = 27 MILLION
YEARS] COMBINES ANIMALS THAT DID NOT LIVE TOGETHER
- Allows large scale evolutionary patterns to be disserned
- FIVE DINOSAUR FAUNAL ASSEMBLAGES CHARACTERIZE THE MESOZOIC - SEE HANDOUT