In 1911, Russian paleontologist Mikhail Dimitrievich Zalessky described a new type of petrified wood from the Donets Basin in modern Ukraine.

In the 1960s, paleontologist Charles B. Beck was able to demonstrate that the fossil wood known as Callixylon and the leaves known as Archaeopteris were actually part of the same plant.

Archaeopteris is a member of a group of free-sporing woody plants called the progymnosperms that are interpreted as distant ancestors of the gymnosperms.

The conifers or Pinophyta are one of four divisions of extant gymnosperms that arose from the seed ferns during the Carboniferous period.

There is evidence[citation needed] that whole fronds were shed together as single units, perhaps seasonally like modern deciduous foliage or like trees in the cypress family Cupressaceae.

The plant had nodal zones that would have been important sites for the subsequent development of lateral roots and branches.

Evidence indicates that Archaeopteris preferred wet soils, growing close to river systems and in floodplain woodlands.

[6] One species, Archaeopteris notosaria, has even been reported from within what was then the Antarctic Circle: leaves and fertile structures were identified from the Waterloo Farm lagerstätte in what is now South Africa.