New evidence indicates the presence of barracuda (Sphyraenidae) and supports a tropical marine environment in the Miocene of Madagascar.

Abstract

Recent exploration of Miocene-age deposits at Nosy Makamby, a small island ~50 km southwest of Mahajanga city in northwestern Madagascar, has led to the recovery of a large sample [82] of isolated barracuda teeth (Sphyraena sp.). in a tropical marine fauna that also includes diverse marine invertebrates, chondrichthyans, bony fishes, turtles, crocodylians, and sirenians. Characteristically for barracudas, the teeth are labiolingually flattened and fang-like with a broadly triangular and blade-like acuminate outline and sharply edged but unserrated cutting margins. These barracudas inhabited an environment that included coral reefs (based on fossil scleractinians) and seagrass beds (evidenced by the epiphytic benthic foraminifera Elphidium sp.). The relatively common occurrence of Miocene barracuda at Nosy Makamby corroborates the presence of a tropical marine ecosystem encircling Madagascar by the Miocene, likely similar overall to the environment found there today.