Didelphoidea

Dear Friends
if with Hemiacodon it was possible to reach the Middle Eocene about forty Mio years ago, with Didelphoidea it is possible to jump far more deep in time and life up to about 100 Mio years ago in the Upper Cretaceous http://en.wikipedia.org/wiki/Cretaceous time in which Pterosaurs http://en.wikipedia.org/wiki/Pterosaur , Ceratopsids http://en.wikipedia.org/wiki/Ceratopsidae
and Tyrannosaurids http://en.wikipedia.org/wiki/Tyrannosauridae populated sky and land. It was certainly a difficult period in which survive for this Didelphoidea small mammal herb-insectivore. Of interest is the black fossilisation of this tooth, his only remain, with the cuspids perfectly preserved and roots seriously degraded. Any comment from you is welcomed
Salutations
Giancarlo