Synura cronbergiae sp. nov., a new species described from two paleogene maar lakes in northern Canada

Abstract

A new species representing the genus Synura, S. cronbergiae, is described from two Paleogene maar lakes situated near the Arctic Circle in northern Canada. The new taxon is characterized by long, slender, siliceous scales each bearing a small forward projecting spine, a base plate with evenly spaced pores and a secondary layer consisting of hexagonal chambers. Each chamber encloses a base plate pore, opens dorsally via a small pore, and collectively the chambers fuse to form a continuous secondary layer. Although S. cronbergiae is believed most closely related to species in the Sectio Synura due to the presence of a distal spine and lack of a median keel, scales superficially resemble those from a rare species in the Sectio Petersenianae, Synura longisquama. The potential evolutionary history, in the context of the genus, is discussed.