''Pseudobornia'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclu ...

s known only from fossils found from the Upper Devonian. It contains a single species ''Pseudobornia ursina'', and is the earliest fossil assigned with certainty to the

Equisetopsida Equisetidae is one of the four subclasses of Polypodiopsida (ferns), a group of vascular plants with a fossil record going back to the Devonian. They are commonly known as horsetails. They typically grow in wet areas, with whorls of needle-like ...

. The first fossils of ''Pseudobornia'' were collected by

Johan Gunnar Andersson Johan Gunnar Andersson (3 July 1874 – 29 October 1960)"Andersson, Johan Gunnar" in ''The New Encyclopædia Britannica''. Chicago: Encyclopædia Britannica Inc., 15th edn., 1992, Vol. 1, p. 385. was a Swedish archaeologist, paleontologist and ge ...

on Bear Island in the 1890s. Hans-Joachim Schweitzer, a paleobotanist, was the first to interpret the fossils as belonging to a large

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

, based on additional fossils discovered in

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S. ...

in the 1960s. The probable relationships within

Equisetidae Equisetidae is one of the four subclasses of Polypodiopsida (ferns), a group of vascular plants with a fossil record going back to the Devonian. They are commonly known as horsetails. They typically grow in wet areas, with whorls of needle-lik ...

are shown in the cladogram below. The position where ''Ibyka'' would be has been added.

References

Horsetails Late Devonian plants Prehistoric plant genera Late Devonian first appearances Late Devonian genus extinctions Prehistoric plants of North America {{devonian-plant-stub