Trochodendron is a genus of flowering plants with one living species, Trochodendron aralioides, and six extinct species known from the fossil record. It was often considered the sole genus in the family Trochodendraceae, though botanists now also include the distinct genus Tetracentron in the family.
Tetracentron is a genus of flowering plant with a sole living species being Tetracentron sinense and several extinct species. It was formerly considered the sole genus in the family Tetracentraceae, though it is now included in the family Trochodendraceae together with the genus Trochodendron.
Trochodendraceae is the only family of flowering plants in the order Trochodendrales. It comprises two extant genera, each with a single species along with up to five additional extinct genera and a number of extinct species. The living species are native to south east Asia. The two living species both have secondary xylem without vessel elements, which is quite rare in angiosperms. As the vessel-free wood suggests primitiveness, these two species have attracted much taxonomic attention.
Trochodendron nastae is an extinct species of flowering plant in the family Trochodendraceae known from fossil leaves found in the early Eocene Ypresian stage Klondike Mountain Formation deposits of northern Washington state. T. nastae is one of the oldest members of the genus Trochodendron, which includes the living species T. aralioides, native to Japan, southern Korea and Taiwan and the coeval extinct species T. drachukii from the McAbee Fossil Beds near Cache Creek, British Columbia.
Dillhoffia is an extinct monotypic genus of flowering plant with a single species, Dillhoffia cachensis known from Ypresian age Eocene fossils found in British Columbia, Canada, and Washington, USA. The genus and species were described from fifteen specimens found in an unnamed formation belonging to the Kamloops group shales; and two specimens from the Klondike Mountain Formation. The unnamed formation outcrops at the McAbee Fossil Beds near Cache Creek, BC, which is designated the type locality while the two U.S. specimens were recovered from the Tom Thumb Tuff member of the Klondike Mountain Formation in Republic, Washington. It is of interest to note that of the Okanagan highlands fossil sites Dillhoffia is only known from two locations, and is absent or has not been identified from the others.
Neviusia dunthornei is an extinct species of flowering plants in the family Rosaceae. The species is solely known from the early Eocene, Ypresian stage, Allenby Formation Lacustrine deposits near the town of Princeton, British Columbia.
Neoephemera antiqua is an extinct species of square-gill mayfly in the family Neoephemeridae that is known from early Eocene, Ypresian stage, lake deposits near the small community of Republic in Ferry County, Washington, USA.
The Klondike Mountain Formation is an Early Eocene (Ypresian) geological formation located in the northeast central area of Washington state. The formation, named for the type location designated in 1962, Klondike Mountain north of Republic, Washington, is composed of volcanic rocks in the upper unit and volcanics plus lacustrine (lakebed) sedimentation in which a lagerstätte with exceptionally well-preserved plant and insect fossils has been found, along with fossil epithermal hot springs.
The McAbee Fossil Beds is a Heritage Site that protects an Eocene Epoch fossil locality east of Cache Creek, British Columbia, Canada, just north of and visible from Provincial Highway 97 / the Trans-Canada Highway. The McAbee Fossil Beds, comprising 548.23 hectares, were officially designated a Provincial Heritage Site under British Columbia's Heritage Conservation Act on July 19, 2012. The site is part of an old lake bed which was deposited about 52 million years ago and is internationally recognised for the diversity of plant, insect, and fish fossils found there. Similar fossil beds in Eocene lake sediments, also known for their well preserved plant, insect and fish fossils, are found at Driftwood Canyon Provincial Park near Smithers in northern British Columbia, on the Horsefly River near Quesnel in central British Columbia, and at Republic in Washington, United States. The Princeton Chert fossil beds in southern British Columbia are also Eocene, but primarily preserve an aquatic plant community. A 2016 review of the early Eocene fossil sites from the interior of British Columbia discusses the history of paleobotanical research at McAbee, the Princeton Chert, Driftwood Canyon, and related Eocene fossil sites such as at Republic.
The Allenby formation is a sedimentary rock formation in British Columbia which was deposited during the Ypresian stage of the Early Eocene. It consists of conglomerates, sandstones with interbedded with shales and coal. The shales contain an abundance of insect, fish and plant fossils known from 1877 and onward, while the Princeton Chert was first indented in the 1950's and is known from anatomically preserved plants.
Rhus malloryi is an extinct species of flowering plant in the sumac family Anacardiaceae. The species is known from fossil leaves found in the early Eocene deposits of northern Washington state, United States. The species was first described from a series of isolated fossil leaves in shale. R. malloryi is one of four sumac species to be described from the Klondike Mountain Formation, and forms a hybrid complex with the other three species.
Tsukada is an extinct genus of flowering plant in the family Nyssaceae related to the modern "dove-tree", Davidia involucrata, containing the single species Tsukada davidiifolia. The genus is known from fossil leaves found in the early Eocene deposits of northern Washington state, United States and a similar aged formation in British Columbia, Canada.
Nuphar carlquistii is an extinct species of flowering plant in the family Nymphaeaceae related to the modern spatterdock, Nuphar advena. The species is known from fossil seeds and fruits found in the early Eocene deposits of northern Washington state, United States, and a similar aged formation in British Columbia, Canada.
Rhus boothillensis is an extinct species of flowering plant in the sumac family Anacardiaceae. The species is known from fossil leaves found in the early Eocene deposits of northern Washington State, United States. The species was first described from fossil leaves found in the Klondike Mountain Formation. Rhus boothillensis likely hybridized with the other Klondike Mountain formation sumac species Rhus garwellii, Rhus malloryi, and Rhus republicensis.
Concavistylon is an extinct genus of flowering plant in the family Trochodendraceae comprising a single species Concavistylon kvacekii. The genus is known from fossils found in Middle Miocene deposits of central Oregon. A second species "Concavistylon" wehrii was originally placed in Concavistylon, but subsequently moved to a new genus Paraconcavistylon in 2020.
Pentacentron is an extinct genus of flowering plant in the family Trochodendraceae, consisting of the single species Pentacentron sternhartae. The genus is known from fossil fruits found in the early Eocene deposits of northern Washington state, United States. P. sternhartae are possibly the fruits belonging to the extinct trochodendraceous leaves Tetracentron hopkinsii.
Tetracentron hopkinsii is an extinct species of flowering plant in the family Trochodendraceae. The species is known from fossil leaves found in the early Eocene deposits of northern Washington state, United States and south Central British Columbia. The species was first described from fossil leaves found in the Allenby Formation. T. hopkinsii are possibly the leaves belonging to the extinct trochodendraceous fruits Pentacentron sternhartae.
Trochodendron postnastae is an extinct species of flowering plant in the family Trochodendraceae. The species is known from fossils found in Middle Miocene deposits of central Oregon. T. postnastae are possibly the leaves belonging to the extinct trochodendraceous fruits Trochodendron rosayi.
Trochodendron rosayi is an extinct species of flowering plant in the family Trochodendraceae. The species is known from fossils found in Middle Miocene deposits of central Oregon. T. rosayi are possibly the fruits belonging to the extinct trochodendraceous leaf species Trochodendron postnastae.
Paraconcavistylon is an extinct genus of flowering plant in the family Trochodendraceae comprises a single species, Paraconcavistylon wehrii. The genus is known from fossil fruits and leaves found in the early Eocene deposits of northern Washington state, United States, and southern British Columbia, Canada. The species was initially described as a member of the related extinct genus Concavistylon as "Concavistylon" wehrii, but subsequently moved to the new genus Paraconcavistylon in 2020 after additional study.
