Gymnosperm Axes

Anatomically preserved gymnosperm axes are relatively abundant in several Permian localities of Antarctica, but their anatomy has rarely been studied in detail, which limits comparison with other Gondwanan plants.

A silicified trunk growing in situ in the Upper Permian Buckley Formation at Coalsack Bluff, in the central Transantarctic Mountains, Antarctica. The trunk has a small heterogeneous pith approximately 4 mm in diameter that contains conspicuous sclerotic nests, shows endarch primary xylem maturation, paired leaf traces, and secondary xylem of the Araucarioxylon-type.

Comparison with contemporaneous gymnosperm axes from Gondwana indicates that the Coalsack Bluff trunk represents a new Permian plant. The anatomical characters of the pith and secondary xylem suggest an affinity with the genus Kaokoxylon Kräusel, previously reported from Permian and Triassic localities of Southern Africa, South America, India, and Australia.