Roger Widenlocher was born in Bône, Algeria. He published his early cartoons and illustrations in magazines like Le Hérisson, Ici Paris and Marius between 1972 and 1975. His name popped up again in 1982, when his comic strip 'Josu Livingroom le Gabian' appeared in the papers through a press agency. This was followed by 'Une Couleur d'Avance', a comic book in commission of Essilor, a French company of ophthalmic equipment, with Xavier Séguin in 1985.
He co-founded the humorous comic magazine La Blatte with Herlé, of which 5 issues appeared. He also started a cooperation with Je Bouquine, for which he made several comic adaptations of novels ('Reynert the Fox', 'Jungle Book', 'La Fontaine's Fables'), as well as the series 'Nabuchodinosaure'. The latter was based on a prehistoric character he had created back in the 1970s, and it turned out to become his longest running serial. Book collections have been published by Widenlocher's regular publisher Dargaud since 1991. In 1993, Widenlocher and Herlé, who writes the scripts, were given the Alph Art Jeunesse award for the series in Angoulême.
Widenlocher and Herlé additionally created the one shot 'Coyote Bill' for Dargaud in 1996