Diploporus
Extinct conifer genus of the yew family from the Eocene and Paleocene.
Diploporus, a conifer genus within the yew family Taxaceae, is extinct. Its sole species, Diploporus torreyoides, is known only from isolated fossil seeds found in chert. These fossils date to the middle Eocene in north central Oregon and the Late Paleocene in south central North Dakota.
Quick Facts
- Species
- torreyoides
Facts from the source article.
History and classification
Diploporus torreyoides is known solely from the Clarno nut beds, which serve as the type locality for both the species and the Clarno Formation. These beds are located roughly 3 kilometers east of Clarno, Oregon, an unincorporated community. Their middle Eocene age, between 45 and 43 million years old, comes from averaging results of zircon fission track dating (43.6 and 43.7 ± 10 million years ago) and argon-argon dating (36.38 ± 1.31 to 46.8 ± 3.36 million years ago). The rock layers consist of tuffaceous sandstones, siltstones, and conglomerates cemented by silica and calcium carbonate. They preserve evidence of either a lake delta environment or periodic floods and volcanic mudflows linked to hot spring activity. An unidentified Diploporus species has also been found in the Sentinel Butte Formation near Almont and Beicegal Creek, North Dakota, where the age is determined by late Tiffanian mammals and associated plant and pollen fossils. The species description relied on seventy-five type specimens. The holotype, UF8542, is housed in the University of Florida’s paleobotanical collections, while the seventy-four paratypes are spread among the National Museum of Natural History, the University of Florida, and the Oregon Museum of Science and Industry. These fossils came from a larger group of about 20,000 specimens gathered between 1942 and 1989 by Thomas Bones, A. W. Hancock, R. A. Scott, Steven R. Manchester, and several high school students. Paleobotanist Steven R. Manchester published the formal description in 1994 in Palaeontographica Americana. He derived the genus name from Greek words meaning “twofold” and “passage,” referencing the paired vascular scars. The species name torreyoides highlights its resemblance to the living genus Torreya.
Description
The seeds of Diploporus are subovoid and bilaterally symmetrical, with a slightly pointed tip and round base, ranging from 6.7 to 8.0 mm in length and 5.4 to 8.0 mm in width. A sharp crest runs along the upper third of the seed, formed by the dorsal and ventral faces. Like other Taxaceae, Diploporus has a pair of vascular scars at the widest point. The seeds differ from Taxus and Torreya in base shape and size, being larger than Taxus seeds but smaller than Torreya seeds.
More in Prehistoric Plants of North America
Spotted an error? Know more?
Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced