Origin and diversification of the Otophysi clade during the Mesozoic: a case of mosaic evolution?

Abstract

Almost all distributed today in freshwater, except by few taxa that inhabited coastal marine waters, the Otophysi clade is a group of teleostean with a formerly worldwide distribution in all continents. The Otophysi fossil record is well known by complete species since the Paleocene However the description of some species in marine sediments from the Cretaceous of Europe, Africa and South America led to a heated debate since the 80’s years about the origin and diversification of the Otophysi clade. The aim of this work is to compare the typical outline of the Weberian Apparatus of extant species, which display the transformation series in the first four occipital vertebrae, with some fossil species otophysan-like. Its presence is an otophysan character, but its morphology and anatomy vary depending on the taxa. The observed species present some modifications in the first four vertebrae.

Keywords

• otophysi
• anatomy
• mosaic evolution
• weberian apparatus