Description

Thyrsopteris murrayana
Fern
Late Jurassic
Myrtle Formation
Buck Mountain, Oregon, USA

74mm frond on 125mm slab.

Thyrsopteris is a tree fern genus known from the Triassic of Italy with specimens documented in the Cretaceous of North America and even Antarctica.  It still lives today – just a single species native to the Juan Fernandez Islands off the coast of Chile.