Nannopterygius finds in the West Kazakhstan region of the Republic of Kazakhstan

Abstract

This article describes the skeletal fragments of new species of ichthyosaurus Nannopterygius mikhailovi sp. nov. and Nannopterygius yakimenkae sp. nov. from the Upper Volga sublayer of the Upper Jurassic of the West Kazakhstan region of the Republic of Kazakhstan (Shchuchkino section). The species are assigned to the genus Nannopterygius. As studies show fragments of skeletons of representatives of the genus Nannopterygius are often found in Late Jurassic sediments at the location of the village of Shchuchkino in the Krasnovsky rural district of the Bayterek district of theWest Kazakhstanregion. Theselection of newspecies is based on thestructure of the forelimbwith awider diaphysis and a large base of the first finger, the two-facet structure of the femurs which make up 2/3 of the forelimb and the peculiar structure of the main occipital bone and the main sphenoid bone, reinforced by outgrowths along the lateral edges, an enlarged area of the humerus indicating an increase in the area of the forelimbs, the interclavicle having a triangular distal shield.