The Hadrosaur-Ceratopsian Empire
The Hadrosaur-Ceratopsian empire was marked by a great animals every bit as impressive as those of the Sauropod-Stegosaur empire - the mighty Tyrannosaurus, formidable Triceratops, tank-like Ankylosaurus, and others. But geographically it was even more limited than the preceeding Iguanodont-Nodosaur empire, being restricted to a single large island, dubbed "Asiamerica" which incorporated what is now east Asia to which the long island of western North America was connected vuia a a land-bridge. All up, the Hadrosaur-Ceratopsian empire lasted some 25 million years - a respectable period of time, but the most impressive animals lived in only the second half of that time. The magafauna was dominated by ornithopods and, later, ceratopsids, both of whicgh lived in vast herds. Tyrannosaurids were the only big carnivores. Alongside these large animals there lived a great diversity of medium- and smaller-sized herbivors, carniovores, and omnivores. In fact teh biota in general was probably richer than teh preceeding ones. perhaps due to increasing opportunities presented by athe angiosperm radiation, and teh new abundance of angiosperm-eating or symbiotic insects. Small Mesozoic mammals as well as lizards and amphibains much like those of today dominated the microvertebrate fauna. This was a time of revolution of plants, which saw teh classic Mesozoic staples of conifers, ferns, cycads, and 
bennettitales progressively replaced by high growth rate angiosperms. This ecosystem probably therefore had a higher primary productivity and population density of large herbivores than the suceeding ones, but not as high as teh age of mammals that was to follow.
Sphenodonta | Squamata | Hypsilophodontidae | Triconodonta | Multituberculata | Symmetrodonta | Eupantotheria
Conifers | Cycads | Ginkgos | Bennettitales |
Isoetales | Lycopodiales | Selaginellales | Equisitales | Ferns | Bennettitales | Gnetophyta
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Links | |
Time of the Titans - the late Jurassic terrestrial megafauna, from the superb BBC series.
The Jurassic Period - 140 Million Years Ago - from American Museum of Natural History - Timelines Exhibit
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