Fig. 1

Phylogenetic relationship between sex determination systems and ambient temperature in reptiles. Relationships for 213 species with known breeding season (GSD = 112 species, TSD = 101 species). Light and dark green represent genotypic and temperature-dependent sex determination, respectively. Squares with colour gradient yellow-red indicate ambient temperatures over breeding seasons: very cold (0–15 °C), cold (16–19 °C), mild (20–23 °C), warm (24–25 °C), and very warm (26–29 °C), respectively. Squares with colour gradient turquoise-black indicate temperature variation during breeding seasons (seasonality). Squares with colour gradient grey-black indicate interannual temperature fluctuation over breeding seasons. Names in the phylogenetic tree correspond to reptile orders or infraorders