New findings of rhyncholites in the Middle and Upper Jurassic of Crimea

Abstract

Until now thefindingsof rhyncholites from the Jurassic marine sediments of Crimea were very scarce. In both the Oxfordian and Kimmeridgian of Crimea, rhyncholites were never found despite the fact that in Western and Central Europe they are very numerous in Middle and Upper Jurassic marine sediments. We have described five new findings of rhyncholites from Crimea whose age ranges from the Upper Callovian to the Kimmeridgian. They belong to the five different species (including three new ones) of the genus Gonatocheilus Till, 1907, which was never previously described in Crimea. We also discuss the taxonomy of rhyncholites and argue that the genus Palaeotheutis Till, 1906 is unavailable according to article 33 of International code of zoological nomenclature and the genus Gonatocheilus Till, 1907 should be used instead of it.