I don’t know how I missed this yesterday. National Geographic has an article on an interesting fossil, dating to about 290 MYA (basically, the beginning of the Permian) , that provides some interesting information on food chains.
About the time I bought my sailboat I started having some really nasty nightmares about sharks. In my dream the would jump out of the water like whales (one even winked at me, but we won’t go there)! Everybody I talked to about it said it was impossible, sharks don’t do that! Below are some pictures of great whites off the coast of South Africa. Clearly, they do! As I understand it they eat seals and attack their prey from below. Since great whites are such powerful swimmers the force of their attack propels them out of the water. Now if I could just find a picture of one winking I would be fully vindicated!
…and really, this has nothing to do with Yttrium!