[1] Smilesaurus was a large gorgonopsian, with a skull length of up to 31 centimeters.

[2][1] Unlike other gorgonopsians, which probably hunted similarly to predatory reptiles, Smilesaurus probably was a true saber-toothed predator which hunted using similar tactics to saber-toothed cats.

[1] It can be distinguished by other rubidgeines by its lack of cranial pachyostosis and rugosoties, and by its relatively small orbits.

[1] Instead, it may be more closely related to Arctops,[3] a position supported by a phylogenetic analysis in 2018.

[4] Below is a cladogram of Gorgonopsia from Bendel et al., 2018:[5] Nochnitsa Viatkogorgon Suchogorgon Sauroctonus Pravoslavlevia Inostrancevia Eriphostoma Gorgonops Cynariops Lycaenops Smilesaurus Arctops Arctognathus Aelurognathus Ruhuhucerberus Sycosaurus Leontosaurus Dinogorgon Clelandina Rubidgea