Cheirolepidiaceae

Cheirolepidiaceae is a family of extinct coniferous plants that had a global distribution 259.0 to 61.7 Ma.[1]

Cheirolepidiaceae Temporal range: Late Triassic to Late Cretaceous PreꞒ Ꞓ O S D C P T J K Pg N
Cheirolepidiaceae in a Danian landscape (reconstruction by F. Guillén)
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Division:	Pinophyta
Class:	Pinopsida
Order:	Pinales
Family:	†Cheirolepidiaceae Turutanova-Ketova 1963
Genera
†Brachyoxylon †Classopollis †Classostrobus †Cupressinocladus †Dicheiropollis †Frenelopsis †Hirmeriella †Pararaucaria †Pseudofrenelopsis †Watsoniocladus

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.[2] 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. The leaf morphology has been noted as being similar to that of halophyte Salicornia. Several members of the family appear to have been adapted for semi-arid and coastal settings.[3]

Some species are thought to have been the first plants to be insect pollinated as they occur in association with extinct pollinating scorpionflies.[4]

The family name Hirmeriellaceae is a junior synonym of Cheirolepidiaceae.[5] In 2020, it was suggested that Hirmeriellaceae was the valid name for the family, with Cheirolepidiaceae being invalid.[6]