The study of fossilized footprints. Ichthyosaurs Sea-dwelling, prehistoric reptiles. A geological period of the Mesozoic Era, between about 200 and 135 million years ago. Dinosaurs flourished during this time. The highest group of like-organisms in scientific classification.
Dinosaurs are part of the Animal Kingdom.
The mass extinction that marked the end of the Cretaceous period, about 65 million years ago. L Lava Molten rock which reaches the Earth's surface through erupting volcanoes. Living Fossil A living fossil is an organism that lived during ancient times and still live today, relatively unchanged, like the horseshoe crab. The Earth's magnetic field is aligned with the north and south poles, and has reversed many times during geologic history. A fossil's magnetic orientation can give clues to its date.