Recently excavated from the legendary Los Pedos amber mines of northern Mexico, an 80 Kg solid block of nearly transparent resin dating from the Oligo-Miocene (ca 25 Myr) contained an astonishing discovery. Entombed within the amber, the perfectly preserved intact head of a small canine, resembling an ancestral relative of the present-day Chihuahua breed of domesticated dog, was revealed to a group of geologists and amber specialists from the Universidad del Perro. Despite the highly suspect nature of the find, gas pyrolysis and infrared spectroscopic analysis of the resin unequivocally confirmed its authenticity. Removal of a tiny tissue sample was undertaken using extreme precautions and new archival methods to prevent tissue degradation and to protect the precious sample within. Sequence analysis of PCR-amplified extracted DNA fragments revealed that it belongs to a now-extinct small mammalian canine species that once roamed the tropical forests of Southern Mexico and Central America. Modern wild chihuahua breeds in Mexico are insectivorous hunters; their ancient ancestors may have hunted insects that congregated on amber resin-exuding Hymenaea trees in the extensive forests that covered Mexico millions of years ago.