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					| Mesozoic Terrestrial Life |  
					| Lecture 24 5/6/98
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					| |  | We continue our discussion of the Mesozoic by examining the terrestrian communities at the time. | 
 |  | The Mesozoic is a time of major changes on land. | 
 |  | Plant communities change from the mesophytic to cenophytic. | 
 |  | Reptiles groups radiate to form all of the modern land vertebrates, plus the dinosuars. | 
 |  | These changes in floras also affected the fauna. | 
 |  | Increased diversity in dinosaur communities may result from flora change. | 
 |  | Triassic and Jurassic floras (mesophytic) | 
 |  | Cretaceous flora (cenophytic) | 
 |  | Jurassic and Cretaceous (205-65 Ma) | 
 |  | Ornithischians (bird-hip dinosaurs) | 
 |  | Iguanodonts (early Cretaceous) | 
 |  | Hadrosaurs (mid-late Cretaceous) | 
 |  | Ankylosaurs (mid Cretaceous) | 
 |  | Ceratopsians (late Cretaceous) | 
 |  | Tyrannosaurus (late Cretaceous) | 
 |  | Archaeopteryx (late Jurassic) | 
 |  | Apatosaurus (Brontosaurus) | 
 |  | probably over 40 m (130 ft) long | 
 |  | Changes in Dinosaur communities | 
 |  | Iguanodonts, Hadrosarus, Ceratopsians | 
 |  | May reflect changes from Mesophytic to Cenophytic floras | 
 |  | evolved around the start of the Jurassic | 
 
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