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.
U Should've Known Better successful on "Billboard"´s component charts. It reached number 6 on the Hot R&B/Hip-Hop Singles & Tracks—Monica's tenth non-consecutive top ten entry on that particular chart—as well as the top ten on the Hot R&B/Hip-Hop Airplay and the top twenty on the Hot 100 Airplay chart. It also appeared on the Rhythmic Top 40 at number 20. The song was ranked 72nd on the Hot R&B/Hip-Hop Singles 2004 year-end chart. The music video for "U Should've Known Better" was shot by director Benny Boom, and produced by Joyce Washington for FM Rocks. It was filmed in various locations throughout Mexico, in