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

• Published in: Antarctic Science
• Main Authors: Chernomorets, Oleksandra, Sakala, Jakub
• Other Authors: Czech Geological Survey
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2021
• Subjects: Antarc*; Antarctic Science; Antarctica; James Ross Island; Ross Island
• Online Access: http://dx.doi.org/10.1017/s0954102021000389; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102021000389

Abstract A 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.