Miocene aged (~23 million year old) sand dollars collected in the D'Angers Region of France. They are still embedded in their original limestone matrix. A sand dollar is a highly flattened form of urchin. They live in shallow marine environments just below the low tide line, buried in the sand or mud. Living, they are covered with velvety looking spines that they use to move. The most diagnostic indicator of fossil sand dollars is the five ovate form on the top side of the skeleton. These are part of the respiratory system and leave an easily identified “flower” on the skeleton. They are active predators, feeding on crustacean larvae, small copepods diatoms and algae. #fyp #foryoupage #desertbloomcrystals #sanddollar