Described basal vertebrates include freshwater hybodont sharks, coelacanths, and lungfish. The living non-tetrapod sarcopterygians include two species of coelacanths and six species of lungfish. In 1987 the Coelacanth Conservation Council advocated the conservation of coelacanths. In coelacanths and early tetrapods the bone is relatively large. Familiar examples of ovoviviparous fish include guppies, angel sharks, and coelacanths. These include mosasaurs such as "Globidens timorensis", lamniforme sharks, coelacanths and the choristodere "Champsosaurus". Included are species such as Atlantic cod, Devil's Hole pupfish, coelacanths, and great white sharks. Modern coelacanths appear larger than those found as fossils. Apart from the coelacanths and the lungfishes, lobe-finned fishes are now extinct. Most extant coelacanths have been found in the Comoros. Several internal traits also aid in differentiating coelacanths from other lobe-finned fish. Anjouan Island and the Grande Comore provide ideal underwater cave habitats for coelacanths. This site preserved abundant remains of Early Jurassic fish like semionotids, palaeoniscids, and coelacanths. A 46-year-old diver, Rehan Bouwer, lost his life searching for coelacanths in June 1998. Pseudomaxillary folds surround the mouth and replace the maxilla, a structure absent in coelacanths.