Fossilized Remains of Former Life

Fossilized Remains of Former Life
Fossils are remains or imprints of organisms, preserved in rocks. (a) Ammonites, members of a group of shelled animals related to modern squid and octopi, survived for some 350 million years. The one who left these remains
floated in the ocean about 200 million years ago. (b) These fossilized bones belonged to a relative of the famous T. rex. Dinosaurs of this group lived from 170
to 65 million years ago. (c) Seed plants like the ones that left these impressions grew in Europe and North America some 280–300 million years ago