Genus: Eopolycotylus ALBRIGHT, GILLETTE & TITUS, 2007a
Etymology: Greek, eos, "dawn" + Polycotylus; earliest oldest Polycotylus.

Species: rankini ALBRIGHT, GILLETTE & TITUS, 2007a
Etymology: In honor of David O. Rankin of Big Water, Utah, discoverer of this and several other important specimens from the Tropic Shale.

Holotype: MNA V9945

Locality: MNA LOC 1496, Glen Canyon National Recreation Area, Kane County, Utah.

Horizon: Tropic Shale, approximately 48 m above local top of Dakota Formation, 42.7 m above top of Bentonite A, 14.8 m above top of Bentonite D.

Biostratigraphy: 16.5m below LO of Mammites; occurs with Mytiloides mytiloides and Morrowites subdepressus, but not with Collignoiceras.

Age: Late Early Turonian Stage, Uppermost Gallic Subepoch, Lower Gulf Epoch, Late Cretaceous.

Material: Anterior part of rostrum, anterior part of mandible, right and left clavicle wiht fused interclavicle, right and left scapula, right and left coracoid, right humerus, right and left ilium, right and left pubis, right and left ischium, right and left femur, most of right rear paddle, most of left rear paddle, 3 cervical vertebrae, 29 dorsal vertebrae (including 3 sacrals), 1 caudal vertebra and several ribs.