Miocene Shark and Batoid Fauna from Nosy Makamby (Mahajanga Basin, Northwestern Madagascar)

PLoS One. 2015 Jun 15;10(6):e0129444. doi: 10.1371/journal.pone.0129444. eCollection 2015.

Abstract

Madagascar is well known for producing exceptional fossils. However, the record for selachians remains relatively poorly known. Paleontological reconnaissance on the island of Nosy Makamby, off northwest Madagascar, has produced a previously undescribed assemblage of Miocene fossils. Based on isolated teeth, ten taxonomic groups are identified: Otodus, Carcharhinus, Galeocerdo, Rhizoprionodon, Sphyrna, Hemipristis, Squatina, Rostroraja, Himantura and Myliobatidae. Six are newly described from Madagascar for the Cenozoic (Galeocerdo, Rhizoprionodon, Sphyrna, Squatina, Rostroraja and Himantura). In association with these specimens, remains of both invertebrates (e.g., corals, gastropods, bivalves) and vertebrates (e.g., bony fish, turtles, crocodylians, and sirenian mammals) were also recovered. The sedimentary facies are highly suggestive of a near-shore/coastal plain depositional environment. This faunal association shares similarities to contemporaneous sites reported from North America and Europe and gives a glimpse into the paleoenvironment of Madagascar's Miocene, suggesting that this region was warm, tropical shallow-water marine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Fossils
  • Madagascar
  • Sharks* / anatomy & histology
  • Spiders* / anatomy & histology

Grants and funding

National Geographic supported fieldwork in 2010 and 2013; in 2011 it was funded by the University of Queensland, and in 2014 by Northern Illinois University.