Genus: Russellosaurus POLCYN & BELL, 2005
Etymology: In honor of Dale Russell for his landmark work on mosasaur morphology and systematics and his numerous contributions to paleontology, and Greek, sauros, "lizard."

Species: coheni POLCYN & BELL, 2005
Etymology: In honour of Mark Cohen of the Dallas Paleontological Society, who discovered and generously donated the specimen.

Holotype: SMU 73056

Locality: SMU locality number 259 (= TMM locality 43209), Cedar Hill, Dallas County, Texas.

Horizon: Arcadia Park Shale, approximately 15 cm above the Kamp Ranch Limestone.

Biostratigraphy: Probably the upper part of the Collignoniceras woollgari zone.

Age: Middle Turonian Stage, Upper Gallic Subepoch, Lower Gulf Epoch, Upper Middle Cretaceous.

Material: Nearly complete disarticulated skull.