The type and sole accepted species of Kentrosaurus is Kentrosaurus aethiopicus, named by Hennig in 1915. Fragmentary fossil material from Wyoming, named Stegosaurus longispinus by Charles Gilmore in 1914, was in 1993 classified as a North American species of Kentrosaurus, as K. longispinus. However, this action was not accepted by the paleontological community, and S. longispinus has been assigned to its own genus, Alcovasaurus, differing from Kentrosaurus in having more elongated tail spikes and the structure of the pelvis and vertebrae.Ulansky, R. E., 2014. Evolution of the stegosaurs (Dinosauria; Ornithischia). Dinologia, 35 pp. [in Russian]. [DOWNLOAD PDF] http://dinoweb.narod.ru/Ulansky_2014_Stegosaurs_evolution.pdf.Ulansky, RE, 2014. Natronasaurus longispinus, 100 years with another name. Dinologia, 10 pp. [In Russian]. Cladogram of the phylogenetic analysis of Stegosauridae conducted by Maidment et al (2019), which recovers a distinct Alcovasaurus:
