In Depth
Although Nikkasaurus is a therapsid, the skull bears a superficial resemblance to varanopid pelycosaurs in terms of overall proportions and shape. Nikkasaurus lived in Russia during the Permian.
Further Reading
– The Nikkasauridae-Problematic Primitive Therapsids from the Late Permian of the Mezen Localities. – Paleontol. J.34 (Suppl. 2), 179–186. – M. F. Ivakhnenko – 2000.