Structure and ontogeny of Vertebraria from silicified Permian sediments in East Antarctica

Abstract

Silicified peat of Permian age from Amery Group sediments near Beaver Lake, East Antarctica represents a swamp dominated by Glossopteris, with little other floristic diversity. Exceptional preservation of small Verterbraria axes has allowed detailed investigations into their structure and early ontogeny. Vertebraria axes have an exarch actinostele, and are clearly roots. The similarity in tracheid anatomy between Vertebraria and abundantly co-occuriing Araucarioxylon wood is confirmed, further supporting the generally accepted link with the Glossopteris plant. Two intergrading types of Vertebraria are described: "polyarch" Vertebraria and "solid cylinder" Vertebraria. These two forms may be ..