Sayimys, WOOD, 1937

Hartman, Julian, Van De Weerd, Andrew A., Bruijn, Hans De & Wessels, Wilma, 2019, An Exceptional Large Sample Of The Early Miocene Ctenodactyline Rodent Sayimys Giganteus, Specific Variation And Taxonomic Implications, Fossil Imprint 75 (3 - 4), pp. 359-382 : 372

Sayimys baskini LÓPEZ- ANTOÑANZAS et SEN, 2003

H o l o t y p e. An isolated right P4.

Ty p e l o c a l i t y. Y747, Potwar Plateau, Pakistan; age of the site: 18.3 Ma.

Additional material from the type locality.

52 cheek teeth, representing all tooth positions except DP3.

O t h e r l o c a l i t i e s w i t h S a y i m y s b a s k i n i. According to López-Antoñanzas and Sen (2003): site Y721 Potwar Plateau, Pakistan and site H.- GSP116 (Banda Daud Shah, the type locality of S. minor) .

D i s c u s s i o n. The collections from the type locality Y747 and from Y721 were studied by Baskin (1996). He concluded that the specimens from these two sites may represent a new species, but refrained from naming it because awaiting additional material of Sayimys minor from its type locality in the Murree Formation at Banda Daud Shah. However, López-Antoñanzas and Sen (2003) did not have this restraint, and described the species S. baskini with type locality Y747, and included specimens from Y721. Not having studied the collection from Pakistan themselves, López-Antoñanzas and Sen (2003) refer to Baskin (1996) for figures, description and measurements. The selection of the P4 as holotype is unfortunate, as it is morphologically the most variable element in large Sayimys populations. Regrettably, the published figures in Baskin (1996) are simplified line drawings, inadequate for a good evaluation of dental morphology. Baskin writes that the single unworn dp4 has a short mesolophid, its hypolophid is transversely directed, lower molars lack a mesolophid, the “M1–2 lack an anteroloph”, thus the paraflexus is absent and proto- and anteroloph are fused. Unfortunately, the only M1–2 of S. minor is rather worn, so the anteroloph is completely fused with the protoloph. We conclude that without more material from the type locality of S. minor that can ascertain the specific difference, S. baskini is a junior synonym of S. minor.