An evidence-based 3D reconstruction of Asteroxylon mackiei, the most complex plant preserved from the Rhynie chert

Three-dimensional reconstructions of the approximately 407 Ma Rhynie-chert lycopsid Asteroxylon mackiei distinguish leafy shoot, root-bearing and rooting axes and show rooting axes arising at anisotomous branch points; this is a species-level body-plan exemplar, not a trait assertion for all Lycophyta.

Lycopodiophyta is profiled at clade level, while Asteroxylon mackiei is used only as a species-level anatomical exemplar and not as a direct ancestor.

The Rhynie-chert exemplar comes from Scotland; it does not define the global distribution or origin centre of Lycopodiophyta.

Asteroxylon’s rooting architecture supports terrestrial anchorage and uptake in that plant, but habitat and growth form vary widely across living and fossil lycophytes.

Three-dimensional reconstruction distinguishes leafy shoot, root-bearing and rooting axes in Asteroxylon, with rooting axes arising at anisotomous branch points.

The 425–0 Ma atlas envelope remains a rounded clade navigation range; the cited 407 Ma Asteroxylon anatomy does not by itself establish a global lycophyte FAD.