Pseudobornia

Pseudobornia is a genus of plants known only from fossils found from the Upper Devonian.^[1] It contains a single species Pseudobornia ursina, and is the earliest fossil assigned with certainty to the Equisetopsida.

Pseudobornia Temporal range: Late Devonian[1] PreꞒ Ꞓ O S D C P T J K Pg N ↓
Pseudobornia ursina
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Division:	Polypodiophyta
Class:	Polypodiopsida
Subclass:	Equisetidae
Order:	†Pseudoborniales
Genus:	†Pseudobornia Nathorst.
Species:	†P. ursina
Binomial name
†Pseudobornia ursina Nathorst.

The first fossils of Pseudobornia were collected by Johan Gunnar Andersson on Bear Island in the 1890s.^[2] Hans-Joachim Schweitzer, a paleobotanist, was the first to interpret the fossils as belonging to a large tree, based on additional fossils discovered in Alaska in the 1960s.^[3][4]

The probable relationships within Equisetidae are shown in the cladogram below. The position where Ibyka would be has been added.^[5]

	†Ibyka(?) †Pseudobornia ursina †Sphenophyllales †Archaeocalamitaceae †Calamitaceae Equisetaceae