EOCENE SELACHIAN FAUNA FROM NEARSHORE MARINE DEPOSITS, AMPAZONY, NORTHWESTERN MADAGASCAR
A new fossil-bearing locality near the northwestern Malagasy town of Ampazony yielded fossils of several selachian genera during the summer field seasons of 2001 and 2003. The sedimentology of the site and the temporal range of selachians recovered suggest that this site is Eocene in age. This designation places the locality within a large gap in Madagascar s Cenozoic fossil record. Extremely few studies have previously been done in this area of Malagasy paleontology, making each new contribution particularly significant. Identification of the Ampazony collection indicates the presence of rays of the family Rhinopteridae and a variety of sharks. These include a species of Carcharhinus, Galeocerdo latidens, and Rhizoprionodon terraenove. This study explored the identification and distribution of Madagascar s Eocene sharks and rays, with particular emphasis on their tooth size, shape, and abundance. The resulting fauna was then compared to selachian distributions throughout the Indian Ocean basin and in other biogeographically significant zones during the Paleocene and Eocene. This research contributes the first significant glimpse into the 80 million year period of Madagascar s marine paleontological record, and helps place into context the selachian faunas collected from the Ampazony region.