Biology and conservation of horseshoe crabs edited by dr john t tanacredi dr mark l botton and dr david r smith offers proceedings from a ground breaking 2007 international symposium at dowling college on the science and conservation of the horseshoe crab horseshoe crabs are well known as living fossils with a geological history covering hundreds of millions of years and an ancestry reaching back 455 million years to the doorstep of the cambrian. Biology and conservation of horseshoe crabs edited by dr john t tanacredi dr mark l botton and dr david r smith offers proceedings from a ground breaking 2007 international symposium at. Biology and conservation of horseshoe crabs edited by dr john t tanacredi dr mark l botton and dr david r smith offers proceedings from a ground breaking 2007 international symposium at dowling college on the science and conservation of the horseshoe crab horseshoe crabs are well known as living fossils with a geological history covering hundreds of millions of years and an ancestry reaching back 455 million years to the doorstep of the cambrian. Biology and conservation of horseshoe crabs edited by dr john t tanacredi dr mark l botton and dr david r smith offers proceedings from a ground breaking 2007 international symposium at dowling college on the science and conservation of the horseshoe crab