Cretaceous mammals (Meniscoessus intermedius, new species, and Alphadon sp.) from the lowermost Oldman Formation, Alberta

Abstract

The 1st mammals discovered in the Upper Cretaceous Oldman Formation, Alberta [Canada] at horizons below the upper part of the unit, can be referred to a new species of the taeniolabidoid multituberculate Meniscoessus Cope and a species of the didelphid marsupial Alphadon Simpson. The new species of Meniscoessus, M. intermedius, appears to have been the direct ancestor of M. major (Russell) from the upper Oldman and Judith River formations, and could have been directly descended from M. ferox Fox, from the Upper Milk Formation, Alberta. The species of Alphadon most closely resembles A. wilsoni Lillegraven, from the Upper Edmonton Formation, Alberta.