He soon joined the layout department and quickly advanced to crew chief, and ultimately to head of layout, thereby having a hand in every Hanna-Barbera show that was produced in those years, including Richie Rich and The Smurfs.
His success at that effort led to more directing assignments, including some of the first long form (an hour or more) animated shows, beginning with The Good, the Bad, and Huckleberry Hound.
[1][2][3][4] When Hanna-Barbera was absorbed by Warner Bros., Grosvenor moved to MGM, where he directed yet another incarnation of The Pink Panther as well as an animated feature based on Babes in Toyland.
In 1997, he joined Universal Cartoon Studios (later renamed Universal Animation Studios), taking over the highly successful The Land Before Time direct-to-video series,[1] beginning with The Land Before Time V: The Mysterious Island.
While critical reception of the series has varied (many of the first sequels received lukewarm to negative reviews, while the latter sequels received more positive reviews), the series has gained a loyal fanbase.