Sigogneau-Russell, Hooker & Ensom 2001. The oldest tribosphenic mammal from Laurasia (Purbeck Limestone Group, Berriasian, Cretaceous, UK) and its bearing on the 'dual origin' of Tribosphenida. Comptes Rendus de l'Academie des Sciences Serie II A Sciences de la Terre et des Planetes, 333(2), 30 Juillet 2001: 141-147