Did you know that Maggy Horvath found a fossil from a plesiosaur that was covered in sediment? She found it in Alberta in the oil sands while she was digging for oil. A plesiosaur is a 20 metre long reptile with a mouth full of sharp teeth so it could hunt fish. It lived 100 million years ago. Sediment is a layer of sand,stone,dirt etc. that settles to the bottom of the ocean. Now that's a great discovery!