Named By: George Gaylord Simpson - 1927.
Classification: Chordata, Mammalia, Marsupialia, Ameridelphia, Didelphimorphia.
Species: A. marshi (type), A. attaragos, A. austrinum, A. clemensi, A. eatoni, A. halleyi, A. jasoni, A. lillegraveni, A. marshi, A. perexiguus, A. sahnii, A. wilsoni.
Size: Estimated about 30 centimetres long.
Known locations: Canada, USA.
Time period: Campanian to Maastrichtian of the Cretaceous.
Fossil representation: Teeth.
Although Alphadon is only named from teeth, these are very similar to possums. Combined with our current knowledge of other late Cretaceous mammals, palaeontologists have concluded that Alphadon was probably a possum-like mammal that fed upon a variety of insects and fruits. Additionally Alphadon is classed as a marsupial which means that young would have been kept in a body pouch. Late Cretaceous North America was a dangerous time for the early mammals and smaller ones like Alphadon would have been easy prey for dinosaurs like Troodon. With this in mind it likely stayed amongst the undergrowth or high in trees where it could either not be seen or simply out of the way of the dinosaurs.