Are Horseshoe Crabs Older Than Fish?
Are Horseshoe Crabs Older Than Fish? They evolved in the shallow seas of the Paleozoic Era (540-248 million years ago) with other primitive arthropods called trilobites, a long extinct close relative of the horseshoe crab. Are horseshoe crabs the oldest crabs? Horseshoe crabs have been around for more than 300 million years, making them even