Dr. Carvalho 'screens' sediment for fossils in a New Jersey streambed.

Most people tend to think of elasmobranchs (sharks and rays) as primitive animals, or a lower form of vertebrates. There is an unfortunate assumption that these animals are not as advanced as bony fishes or more recent animals, simply because they have existed for somewhere between 420 million and 450 million years. The more we examine their anatomy, however, the more we find that elasmobranchs are actually very specialized animals. For example, the particular calcification of their skeletal cartilage is an evolutionary novelty, rather than a primitive or unevolved character. Their longevity is proof of their evolutionary success.

Little is known about sharks, not only in terms of taxonomy and biology, but also in terms of their biomedical potential. There are only about a dozen people in the entire world who study the taxonomy and systematics of these animals. Marcelo refutes the common attitude toward sharks that they are terrifying predators of the sea that should be eliminated; instead he is a great advocate for the view that sharks and rays are very important to humans. There remains a wealth of information that we have yet to learn about them.