A multidisciplinary study of Iberian Chalcolithic dogs

•This research employed a multidisciplinary approach to study ancient dogs.•We aimed to understand humans’ interest in the maintenance and breeding of dogs.•Iberian Chalcolithic dogs already exhibited signs of body size variation.•Dental analyses revealed that dogs died young without signs of periodontitis.•We detected mitogenomic variability through the presence of clades A and C.•Molecular sex inference allowed the identification of one female and two males.