Creania lacyae gen. nov et sp nov and Synedropsis cheethamii sp nov., fossil indicators of Antarctic sea ice?

• Main Authors: Olney, Matthew P., Bohaty, Steven M., Harwood, David M., Scherer, Reed P.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2009
• Subjects: Antarctic; Victoria Land; Antarc*; Antarctica; Sea ice
• Online Access: https://eprints.soton.ac.uk/71751/

A new fossil araphid genus and species, Creania lacyae, and a new fossil araphid species, Synedropsis cheethamii are described from Oligocene to lower Miocene sediments recovered from the Victoria Land Basin, Antarctica. The new genus Creania possesses round, uniseriate areolae, a central sternum and apical fields composed of a row of short rectangular openings. Presence of two distinctive rimoportulae per valve, and the shape and number of apical field openings are the primary features that distinguish the genus. The genus is (at present) monospecific. The new species Synedropsis cheethamii is closely related to the modern species Synedropsis lata and S. lato var. angustata but is distinguished by its less dense stria, the shape and position of the rimoportula and the shape and structure of the apical slit field. The presence of Synedropsis in upper Oligocene sediments marks the earliest Occurrence of this genus which is commonly associated with sea-ice. We Postulate that both Synedropsis cheethamii and Creania lacyae may be utilized as paleo sea-ice indicators. New taxa formally proposed here are: Synedropsis cheethamii Olney sp. nov., Creania Olney gen. nov. and Creania lacyae Olney sp. nov.