Did you know that until the 16th century, mariners and seamen referred to sharks as "sea dogs"? Sharks have actually been around for a long time--many scientists think a variation of the shark existed from over 420 million years ago! Sharks belong to a large group of fish that have a skeleton made of cartilage instead of bone. Because of this, the only fossilized remains of ancient sharks are their teeth.The teeth of sharks grow in constantly to replace older ones that wear out. It is estimated that sharks can lose up to 20,000 teeth in their lifetime. In fact, some ancient sharks had teeth that grew as long as 4 inches.
Want a great example of a shark tooth fossil? Invest in this inexpensive, authentic shark tooth fossil specimen to spruce up your science classroom! Also makes a unique gift, stocking stuffer, or party favor for adults and children alike!
This science kit is an essential introduction to physics knowledge!
Head into the lab for an in-depth investigation of genetics and DNA!
Ever wonder how to survive in the wilderness? These cards can help!
Make the coolest 3D pin art on your desk with this amazing desk toy.
This classic device is used to demonstrate the conservation of mechanical energy.
Build an electromagnet, an electrical catapult, a doorbell chime, a telegraph, and more with this kit!