A new Cenozoic cyclostome bryozoan genus from Argentina and New Zealand: strengthening the biogeographical links between South America and Australasia

Abstract

Taylor, P.D. & Brezina, S., February 2018. A new Cenozoic cyclostome bryozoan genus from Argentina and New Zealand: strengthening the biogeographical links between South America and Australasia. Alcheringa XX, xx–xx. ISSN 0311-5518.Uniserial encrusting cyclostome bryozoans (‘stomatoporiforms’) are especially challenging to study taxonomically because of the paucity of their morphological characters. Here we introduce Axilosoecia gen. nov. for two previously undescribed species characterized by gonozooidal brood chambers located in the axils of branch bifurcations. The type species, Axilosoecia giselae sp. nov., comes from the upper, Danian part of the Roca Formation of La Pampa, Argentina; the second species, Axilosoecia mediorubiensis sp. nov., is from the lower Miocene of Southland, New Zealand. On account of its basal gonozooids, Axilosoecia is assigned to the family Oncousoeciidae despite similarities in colony form with Stomatoporidae. The two known occurrences of this new genus support previously suggested biogeographical links between southern South America and Australasia.Paul D. Taylor, Department of Earth Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK [p.taylor@nhm.ac.uk]; Soledad Brezina, Instituto de Investigación en Paleobiología y Geología, Unidad de doble dependencia, Universidad Nacional de Río Negro—Consejo Nacional de Investigaciones Científicas y Técnicas, Av. Roca 1242, R8332FDJ, General Roca, Río Negro, Argentina [sbrezina@unrn.edu.ar].