Answer: Dinosaurs
Many forms of plants, invertebrates, and fishes evolved during the Mesozoic Era. Since the dinosaurs were the dominant animals on land then, the Mesozoic Era is called the Age of Reptiles. Dinosaurs, however, became extinct even before the end of the Era.
Possession of flagellum is not a taxonomic feature. many different unrelated organisms have flagellum. euglena, zooflagellates but also some fungi or even human sperm cells.
Explanation:
The valence electrons determine the group the elements belong in the periodic table. For example, the element sodium, Na, has a valence electron of one and so it belongs to Group 1 in the periodic table. Another example is Aluminium, Al, which has a valence electron of three and therefore it belongs to Group 3 in the periodic table.
Increases the rate of reaction