Introduction

Introduction

Why are horseshoe crabs often called "living fossils"?

Specimen from the Lapworth Museum of Geology, the University of Birmingham, UK and photo by Dr Lyall I. Anderson, National Museums of Scotland, Edinburgh An "ancient" and a "modern" horseshoe crab

Horseshoe crabs have been on earth for over 300 million years, long before the dinosaurs appeared. According to the fossil records, the basic body form of horseshoe crabs has remained almost unchanged in the past millions of years. Therefore they are often called "living fossils".