Cheirolepidiaceae is a family of extinct coniferous plants. This family of conifers, superficially similar to Cupressaceae, was a significant part of the flora of the Mesozoic, around 252 to 66 million years ago (Axsmith et al., 2004). They are united by the possession of a distinctive pollen type assigned to the form genus Classopollis. The name Frenelopsidaceae (as a separate family) or "frenelopsids" has been used for a group of Cheirolepidiaceae with jointed stems, thick internode cuticles, sheathing leaf bases and reduced free leaf tips.