Lemur of mouse lemurs, the gray mouse lemur ("M. murinus"), golden-brown mouse lemur ("M. ravelobensis"), and Goodman's mouse lemur ("M. lehilahytsara") were considered the same species until recently, when genetic tests identified them as cryptic species. The lemur dentition is heterodont (having multiple tooth morphologies) and derives from an ancestral primate permanent dentition of . Indriids, sportive lemurs, the aye-aye, and the extinct sloth lemurs, monkey lemurs, and koala lemurs have reduced dentitions, having lost incisors, canines, or premolars. The ancestral deciduous dentition is , but young indriids, aye-ayes, koala lemurs, sloth lemurs, and probably monkey lemurs have fewer deciduous teeth.
I Should Have Known Better scene of "A Hard Day's Night". It was in fact filmed in a van, with crew members rocking the vehicle to fake the action of a train in motion. Paul McCartney is seen lip-syncing in the song in both the train scene and in the live performance at the end of the film, despite not singing in the actual recording. I Should Have Known Better "I Should Have Known Better" is a song by English rock band the Beatles composed by John Lennon (credited to Lennon–McCartney), and originally issued on "A Hard Day's Night", their soundtrack for the film of