Priscagamidae is an extinct family of iguanian lizards[1] known from the Late Cretaceous of Mongolia and China and the Eocene of India,[3] spanning a range from 75 to 54 million years ago. It includes the genera Heterodontagama, Mimeosaurus, Phrynosomimus, Priscagama, and possibly Pleurodontagama.[4] The first fossils of priscagamids were found in the Djadochta and Khermeen Tsav formations of Mongolia.[2] More recently they have been found in the Cambay Formation in India, leading to the naming of Heterodontagama in 2013.[5] Priscagamidae was originally described as a subfamily of Agamidae called Priscagaminae in 1984,[2] but it was reclassified as a distinct family in 1989.[1] Most phylogenetic analyses (analyses of evolutionary relationships) still find a close relationship between Priscagamidae and Agamidae (both have been grouped under a clade called Chamaeleontiformes[6]), although a 2015 study found it to be basal to all other iguanian clades, warranting its removal from Iguania and placement in a larger clade called Iguanomorpha.[7]