Revision of some problematic Early Cretaceous ammonite species described by H. Coquand (1880)

The finding and analysis of the type specimens of some Barremian ammonite species described, but not depicted by Coquand (1880, Bull. de l’Acad. d’Hippone 15, 1-449), has led us to the revise their current interpretation. The purpose of the manuscript is to re-describe the three most commonly used Early Cretaceous species described by Coquand (1880, Bull. de l’Acad. d’Hippone 15, 1-449) and is to consider one species as a nomen dubium. The original type material of Holcodiscus diversecostatus, Holcodiscus metamorphicus and Heinzia heinzi shows that these species have been usually misidentified in the literature. We designate lectotypes for these species, thus amending some previous invalid designations, and fully discuss their actual status and synonymy. In addition, we conclude that the use of the nominal species “Ammonites mazuca” should be fully avoided, it is considered as a nomen dubium. The type material is apparently seems to be lost so its application is very doubtful.