Collectable Fossil Horseshoe Crab ancient artifacts educational tool kids love For Sale

Ancient artifacts …we think a Horse Shoe Crab. To big for a Trilobite. Truth is I know nothing about this field. It’s been a loved collectors item for our home. Picked up on a momentous family trek to see this Great countries beautifull caves and caverns. She was purchased for $400 8 years ago out side a cave in Virginia? Tennessee? Missouri? Kentucky? Indiana? It’s colors change with the surroundings. It’s unclear if authentic due to conflicting info. It’s been loved and displayed at schools for years as the real deal. Borrowed many many times. Displayed and enjoyed as the coolest one. I am Hoping to find a new home to appreciate her as she has been loved and has represented all fossils beautifully. She out lived her box and credentials but she still rocks. 🤫please don’t tell her she’s not real. She would be so crushed. Thank you❤️