Life in the Mesozoic and Cenozoic eras
The Mesozoic era lasted from about 252 to 66 million years ago (about 186 million years) and consists of the Triassic, Jurassic and Cretaceous periods. On land gymnosperms (conifers, cycads) dominated; in the Cretaceous angiosperms (flowering plants) appeared and spread fast, evolving together with insects as pollinators. Among animals, reptiles, especially dinosaurs, dominated; ichthyosaurs and other marine reptiles lived in the seas and pterosaurs flew in the sky. About 225 million years ago the first small mammals appeared; at the end of the Jurassic (about 150 million years ago) there were feathered, toothed, long-tailed bird-like dinosaurs such as Archaeopteryx. Modern birds are a living group of dinosaurs (descended from theropods). At the start of the era the land was a single supercontinent, Pangaea; during the Jurassic and Cretaceous it broke up and the continents slowly drifted apart. At the end of the Mesozoic, about 66 million years ago, a large asteroid struck near what is now Mexico (Chicxulub) and, together with volcanic activity, caused a mass extinction: all dinosaurs except birds, the pterosaurs and the marine reptiles disappeared. The Cenozoic era began 66 million years ago and continues today; it has the Palaeogene, Neogene and Quaternary periods (the name “Tertiary” in older textbooks is no longer used). After the dinosaurs vanished, mammals and birds diversified and filled many ecological niches (adaptive radiation): horses, whales, carnivores, primates. In the Neogene grasslands and savannas spread. The Quaternary (which began about 2.6 million years ago) has alternating glacial and warm periods; humans appeared in it. Today species are being lost very fast because of human activity, which is why nature protection is necessary.
“Find the era”: cards with names of animals and plants (trilobite, dinosaur, fern forest, mammoth, Archaeopteryx); groups place them in the correct era and period column.