Raw Landmarks for describe head shape in two spiny lizards from central Mexico

Geometric morphometric techniques offer valuable insights into the developmental processes underlying morphological variation. This dataset includes two-dimensional raw and procrustes coordinates (X and Y) for 22 cranial landmarks digitized on dorsal images of two lizard species: Sceloporus grammicus and Sceloporus aeneus. These species differ in their reproductive mode—viviparous and oviparous, respectively. Landmark data were collected from adult males and females to test whether developmental instability, inferred from fluctuating asymmetry in head shape, exhibits sex-specific patterns within each species. Landmarks were digitized using TPSDig and subsequently visualized and analyzed in MorphoJ. The dataset is accompanied by an image file ("Landmarks.jpg") illustrating the anatomical location of each landmark. All data were collected under the scientific collecting permit SGPA/DGVS/10352/21 issued by SEMARNAT (Mexico). The resulting analyses found no evidence of sex-specific developmental instability in either species. These data can be reused for further morphometric investigations, comparative analyses across squamate taxa, or as a reference for studies in evolutionary developmental biology.