Late Cretaceous
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Late Cretaceous (also called the Upper Cretaceous) refers toe the second half of the Cretaceous period, named after the famous white chalk cliffs of southern England, which date from this time.
This was a period of great success for dinosaurs, with many new types appearing and diversifying, such as the Tyrannosaurs, duck bills, Ankylosauridae, and horned dinosaurs in Asiamerica (Western North America and eastern Asia), and Titanosaurs and Abelisaurs in Gondwana.
Birds become increasingly common and diverse, replacing the pterosaurs which retreat to incraesingly specialised ecological niches.
In the seas, mosasaurs suddenly appear and undergo a spectacular evolutionary radiation. Modern sharks also appear, and giant-penguin-like Polycotylidae|plolycotylid]] pliosaurs (3 meters long) and huge long-necked elasmosaurs (13 meters long) also diversify. These predators feed on the numerous teleost fishes, which in turn evolve into new advanced and modern forms (Neoteleostei).
Near the end of the Cretaceous, flowering plants diversify, and didelphid marsupials and primitive placental mammals were also common.