Placental and embryonic tissues exhibit aromatase activity in the viviparous lizard Niveoscincus metallicus.

•We measured aromatase in maternal and embryonic tissues in a viviparous lizard.•Placental aromatase activity decreases at from early to late gestation.•Aromatase activity in embryonic brains peaks in mid-development.•Aromatase activity in embryonic gonads rises significantly in mid-development.•Aromatase is important in gestation and development in viviparous lizards.