The species was first described in 1863 from fossils found in the outcrops of the Late
Paleocene-Middle
Eocene Chuckanut Formation around
Birch Bay, Washington. The species was originally described as
Taxodium occidentale by
John Strong Newberry. Fossilized
Metasequoia-like remains were noted in Europe and North America from the 1800s on, but were assigned to the
cupressaceous genera
Sequoia (redwoods) and
Taxodium (
bald cypresses). It was not until the living species
Metasequoia glyptostroboides was discovered and described from a remote area of China during the 1940s, that the affinity of many of the
fossils became apparent. In 1951, the species was reassigned to
Metasequoia as
M. occidentalis by
Ralph Works Chaney based on the close resemblance to living
Metasequoia. With a few notable exceptions, it has been claimed that the majority of the fossils documented in the literature show that
M. occidentalis was indistigushable from living
M. glyptostroboides. ==Description==