Species: haysomi ENSOM & SIGOGNEAU-RUSSELL, 1998
Etymology: In hour of W. T. Hayson, a quarry owner of the Isle of Purbeck,
who drew the attention of the senior author to the Sunnydown site.
Holotye: DORCM GS 433
Locality: Sunnydown Farm Quarry, Langton Matravers, Dorset County, England, Southern United Kingdom.
Horizon: Cherry Freshwater Member, Lulworth Formation, Purbeck Limestone Group.
Biostratigraphy:
Age: ?Berriasian Stage, Lower Neocomian Subepoch, Lower Early Cretaceous Epoch, Early Cretaceous.
Material: Right lower molar.
Referred material:
DORCM GS 376: Right lower molar.
DORCM GS 502: Right lower molar.
DORCM GS 438: Left lower molar.
DORCM GS 501: left lower molar.
DORCM GS 625: Left lower molar.
DORCM GS 747: Right lower molar.