Mixoxylon australe gen. et sp. nov., a unique homoxylous wood with non-angiosperm affinity from the Lower Cretaceous of Antarctica (Albian, James Ross Island)

Abstract

AbstractA unique homoxylous wood is described from the Albian Lewis Hill Member of the Whisky Bay Formation on James Ross Island as Mixoxylon australe Chernomorets & Sakala, gen. et sp. nov. This fossil taxon shows an unusual combination of features in having indistinct growth rings with a significantly wider earlywood zone than latewood zone, tracheids with scalariform to araucarian pitting, exclusively uniseriate rays with distinctly pitted both tangential and horizontal walls and araucarioid to podocarpoid cross-field pits. Its characteristics are intermediate between Phoroxylon Sze and Sahnioxylon Bose & Sah, so a new genus is proposed. Its systematic affinities are dubious, but it represents the southernmost evidence of the homoxylous Mesozoic wood with scalariform pitting described so far.