Cricetulus

Cricetulus is a genus of rodent in the family Cricetidae ; it has seven member species that inhabit arid or semi-arid regions in Eurasia.
They tend to be more ratlike in appearance than typical hamsters, hence the common name ratlike hamster. Many of the species are considered dwarf hamsters. However, members of the genera Allocricetulus, Tscherskia, and Cansumys are often called ratlike hamsters, and so are considered to be members of the genus Cricetulus by many authorities.

Species

Three species are universally accepted in this genus:

Cricetulus barabensis — Chinese striped hamster
Cricetulus longicaudatus — long-tailed dwarf hamster
Cricetulus sokolovi — Sokolov's dwarf hamster

Two species were moved to the genus Urocricetus in 2018, but have historically been included in this genus:

Urocricetus alticola — Tibetan dwarf hamster
Urocricetus kamensis — Kam dwarf hamster

Other species are sometimes recognized, but further research is likely needed to consider them valid:

Cricetulus griseus — usually considered a synonym of Cricetulus barabensis
Cricetulus lama — considered a synonym of Urocricetus kamensis by the American Society of Mammalogists, but considered valid by the IUCN
Cricetulus tibetanus — considered a synonym of Urocricetus kamensis by the American Society of Mammalogists, but considered valid by the IUCN

Additionally, the grey dwarf hamster Nothocricetulus migratorius was included in this genus until 2018.