An Early Devonian permineralized rhyniopsid from the Battery Point Formation of Gaspé (Canada)

Abstract

The Emsian deposits of the Battery Point Formation (Gaspé, Canada) host the most diverse Early Devonian flora in North America. Most of this diversity has been described from plant compressions, but the permineralized component of the flora is incompletely explored. Based on > 15 axes studied in serial sections, we describe a new anatomically preserved rhyniopsid from the Battery Point Formation, Eddianna gaspiana gen. & sp. nov. Eddianna axes are up to 2 mm in diameter and have a well-developed terete xylem strand with potential centrarch maturation (comprising 80% of the cross-sectional surface area) that features Sennicaulis-type tracheid wall thickenings. A thin layer interpreted as phloem is preserved around the central xylem and an irregular sclerenchymatous cortex forms longitudinal anastomosing ridges on the outside of the axes. The anatomy of Eddianna axes suggests that they represent lower portions, specialized in efficient water transfer, of a larger plant, distal regions of which have yet to be discovered. Eddianna, the first permineralized rhyniopsid described from the Battery Point Formation, is one of only four anatomically preserved plants reported from this unit. These fossils reiterate the potential for additional discoveries of anatomically preserved plants in the Battery Point Formation.