Palaeocarpinus

Description

Palaeocarpinus is an extinct genus of plants placed in the Betulaceae subfamily Coryloideae. The genus had a wide spread circumboreal distribution, with species found in North America, Europe, and Asia. The first appearance dates to the Early Paleocene and species are spread through the Paleocene and Eocene with the youngest species occurring at the Eocene-Oligocene boundary. A total of thirteen species have been named with a small grouping of referred specimens that have not been redescribed in the modern literature. Three species have been named from Asia, in 1996, 1998, and 2000. The type species and the first described species are both from Europe, being named in 1981 and 1859, though a North American species is reported in Northern Europe as well. North America has the largest diversity of the genus, with two groups of species known and several outliers. The first species was reported from the Okanagan Highlands in Canada and two additional species were named from the Highlands in 2003. A series of species is known from sites across the Great Plains-Rocky Mountains, with species named in 1992, 1996, 2004, and 2021. An additional species was described in 2021 from Oregon, and an undescribed fossil was reported from the Yukon but subsequently lost in transport. The first two species to be described were placed into several unrelated genera or into a form taxon for fruits before being moved into the genus. Palaeocarpinus is now placed basally into Coryloideae, with an unresolved relationship to the two modern coryloid tribes Coryleae and Carpinieae. The Palaeocarpinus plant was likely wind pollinated as with other Betulaceae species, while the fruits were possibly being wind or animal dispersed at maturity.