Curious Minds Did You Know? Megalodon fossils have been found in the state of Utah in the USA. This tells scientists that the middle of North America was probably entirely under water.
Trilobites meaning three lobes are a well-known fossil group of extinct marine arthropods that form the class Trilobita. The earliest trilobites known from the fossil records are dated to some 520 to 540 million years ago.
The largest Trilobites may have been 45 centimetres long and weighed 4.5 kilograms. They had many different lifestyles over their 300 million years on the planet – some moved across the seabed as predators, scavengers, or filter feeders whereas some swam, feeding on plankton and some even crawled on land!