Huehuecuetzpalli mixtecus is an extinct lizard from the Early Cretaceous (specifically the middle to late Aptian stage) Tlayúa Formation in Tepexi de Rodríguez, Central Mexico. Although it is not the oldest known lizard, Huehuecuetzpalli may be the most basal member of Squamata (the group that includes lizards and snakes), making it an important taxon in understanding the origins of squamates. It may or may not be a basal member of Iguania, a large clade of lizards that traditionally includes the iguanas and their close relatives, chameleons, and agamids: if it is an iguanian, H. mixtecus represents the earliest major offshoot of the squamate evolutionary tree.