Birthday of the Armadillo) is the debut studio album by Brazilian music duo Sandy & Junior, released by Philips and PolyGram on 1991.

[2] The title of the album refers to a joke with the social relations between the animals of the forest and its themes allude to the harmony of nature and the teachings that the life in the field propitiates.

[1] The biggest hits of the album were "Aniversário do Tatu" and "Maria Chiquinha" (a re-reading of the song originally released by Sonia Mamed and Evaldo Gouveia in 1961).

[5] After winning a national screening at the end of 1989, during a "Maria Chiquinha" performance on the Som Brasil TV series, the brothers were invited by the label PolyGram to sign a three-album contract, which began the professional career of the young duo.

Aniversário do Tatu was recorded in 1990 and its sound was influenced by the father of the pair, the sertanejo singer Xororó; he produced the album and also wrote some material for the record; some in tandem with Noely, his wife and mother of the duo.