Gerhardodon
Scientific classification
Kingdom: Animalia
Therapsida
Class: Mammalia
Order: Multituberculata
Family: Pinheirodontidae
Genus: Gerhardodon
Species
  G. purbeckensis
Ref.

Gerhardodon is an extinct mammal from the Lower Cretaceous rocks of southern England. It was a member of the also extinct order of Multituberculata, and lived with such dinosaurs as Iguanodon.
(For the technically minded, suborder "Plagiaulacida", family Pinheirodontidae.)

Genus: Gerhardodon Kielan-Jaworowska Z & Ensom PC, 1992
'Gerhard’s tooth'

Species: Gerhardodon purbeckensis Kielan-Jaworowska Z & Ensom PC, 1992
Place: Durlston Bay, Dorset
Country: England
Age: Berriasian, Lower Cretaceous
Remarks: A multituberculate mammal (Multituberculata) from the Isle of Purbeck, Dorset. This formation is sometimes considered to be partly Upper Jurassic.
Reference: Kielan-Jaworowska & Ensom (1992), Multituberculate Mammals from the Upper Jurassic Purbeck Limestone Formation of southern England. Paleontology, 35, p.95-126.

Page reference: Kielan-Jaworowska Z & Hurum JH (2001), Phylogeny and Systematics of multituberculate mammals. Paleontology 44, p.389-429.

(This information has been derived from [1] MESOZOIC MAMMALS; Basal Multituberculata, an internet directory. As that's my webpage, there are no issues of copyright. Trevor Dykes)