- Project title
- Inside the head of the first jawed vertebrates
- Description of the project
- In 1992, a fieldtrip organized by the Bureau des Ressources Géologiques et Minières and Muséum National d'Histoire Naturelle de Paris, allowed the collect of roughly two hundred specimens of placoderm (first jawed vertebrates) from Saudi Arabia. Those remains, found in deposits of 405 million years, are extremely well preserved and represent early unknown representatives of placoderm.
The extant jawed vertebrates, i.e. cartilaginous fishes, bony fishes and four-limbed vertebrates, display contrasting characters. The polarities - in a phylogenetic framework - of these differences, and the morphology of the last common ancestor of extant jawed vertebrates, are the subject of continuing debate. Placoderms are at the basis of the jawed vertebrate tree and, for several years, they appear as the key to understand the early evolution of vertebrate. Early representatives of placoderms could help us in the understanding of the vertebrate relationships. Unfortunately, they are quite scarce in the fossil record. The Saudi fauna offers us access to such a material and could therefore be useful in the deciphering of those relationships.
The occurrence of placoderms in elderly Saudi deposits of 405 million years raises also interesting paleobiogeographic issues that this project offers to resolve.
Works done by the platform AST-RX