'Kazaklambia convincens' comb. nov., a primitive juvenile lambeosaurine from the Santonian of Kazakhstan

Abstract

The holotype of 'Procheneosaurus convincens', a juvenile lambeosaurine, is the most complete hadrosaurid known from Kazakhstan. North American species of 'Procheneosaurus' are considered juveniles of 'Corythosaurus', 'Hypacrosaurus', and 'Lambeosaurus', rendering the generic name unusable. A replacement name, 'Kazaklambia convincens' comb. nov., is herein proposed as this specimen is morphologically distinct from other Eurasian taxa and known juvenile lambeosaurines at a similar ontogenetic stage in having a prefrontal process of the postorbital with a dorsal thickening forming a dome lateral to the frontal dome, doming of the nasal anterodorsal to the orbit, and a frontal length/width ratio <1. The juvenile status of 'Kazaklambia' makes phylogenetic placement difficult; however, morphometric and morphological information (particularly in relation to the hollow cranial crest and the length of the frontal) suggest a close affiliation with the basal lambeosaurines 'Amurosaurus' and 'Tsintaosaurus', and support the hypothesis for an Asian origin for Lambeosaurinae.