TY - JOUR
T1 - Oldest record of the scale-leaved clade of Podocarpaceae, early Paleocene of Patagonia, Argentina
AU - Andruchow-Colombo, Ana
AU - Escapa, Ignacio H.
AU - Carpenter, Raymond J.
AU - Hill, Robert S.
AU - Iglesias, Ari
AU - Abarzua, Ana M.
AU - Wilf, Peter
N1 - Funding Information:
The authors thank L. Reiner and E. Ruigomez for helping with the curation of the fossil specimens, A. Vilela for the curation of the L. fonkii specimens at PBP Herbarium, I. Davie for his help in cuticle preparation, Aluar Aluminio Argentino SAIC and Servicio de Microscopía de Barrido del Museo de La Plata for providing access to the SEM, and M. Luquet and P. Sarmiento for technical support. Thanks to the Secretaría de Cultura and Secretaría de Turismo y Áreas Protegidas from Chubut Province, to A. Balercia, Bochatey Family, and H. Visser for facilitating land access, and to P. Puerta, K. R. Johnson, M. Caffa, L. Canessa and many others for help in the field. We are indebted to M. Gandolfo, K. Nixon, A. Stalter and P. Fraissinet for providing access to the herbarium and plant anatomy collection of the L.H. Bailey Hortorium at Cornell University; to M. Pole, who kindly provided images of New Zealand fossil material; to L. Aagesen, N.B. Degiani, I. Schonberger, and M. Tomescu for providing podocarp material; and to M. Krause and W. Clyde for their help with the geology. We are indebted to C. Mays and two anonymous reviewers for their remarks and suggestions that greatly improved the quality of the manuscript. Recent support for this research came from National Science Foundation (NSF) grant DEB-1556666, and prior support came from NSF grants DEB-0919071 and DEB-0345750. We also thank the Argentinean National Scientific and Technical Research Council (CONICET) for research funding.
PY - 2019/1/2
Y1 - 2019/1/2
N2 - A new podocarpaceous conifer is described from the early Danian Salamanca Formation (southern Chubut, Patagonia, Argentina) based on compressions of leafy branches with cuticular remains. Kirketapel salamanquensis gen. et sp. nov. has amphistomatic, scale-like leaves with marginal frills distinguishable at the apex; stomata oriented randomly in relation to the major axis of the leaf with four to five subsidiary cells and extremely reduced Florin rings; and irregularly shaped epidermal cells. We compare K. salamanquensis with extant and extinct members of the imbricate-leaved podocarps, among which it closely resembles Florin’s Dacrydium group C genera (i.e., Lagarostrobos, Manoao, Lepidothamnus and Halocarpus). Among these genera, only Lepidothamnus has a living representative in South America, the Chilean L. fonkii, whose leaf macro- and micromorphological characters are described in detail for comparison. Overall, the Patagonian fossil species is most similar to the extant and extinct members of Lagarostrobos in its cuticular micromorphology; however, macromorphological characters, such as the leaf size, apex curvature and mode of flattening, clearly differentiate it from all four genera of Dacrydium group C. We include Kirketapel salamanquensis in a combined molecular and morphological phylogenetic analysis conducted under the maximum parsimony criterion. The new, early Paleocene fossil taxon is confidently recovered as part of the scale-leaved clade as defined herein, which also includes Halocarpus, Phyllocladus, Lepidothamnus, Parasitaxus, Lagarostrobos and Manoao, and it constitutes the oldest record known for the group by at least 17 million years as well as its first fossil occurrence outside Australasia, establishing a widespread Gondwanan history. Furthermore, based on its oldest locality of occurrence, K. salamanquensis shows that the divergence of the total group of the scale-leaved podocarps occurred by at least 65 million years ago, adding to the growing systematic knowledge of earliest Cenozoic macrofloras in the Southern Hemisphere. Ana Andruchow-Colombo [[email protected]] and Ignacio Escapa [[email protected]] CONICET, Museo Paleontológico Egidio Feruglio Av. Fontana 140, Trelew 9100, Chubut, Argentina; Raymond J. Carpenter* [[email protected]] School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tas. 7001, Australia; Robert S. Hill [[email protected]] School of Biological Sciences and Environment Institute, University of Adelaide, Adelaide, SA 5005, Australia; Ari Iglesias [[email protected]] CONICET, Instituto de Investigaciones en Biodiversidad y Medioambiente INIBIOMA-CONICET, Universidad Nacional del COMAHUE, Quintral 1250, San Carlos de Bariloche 8400, Río Negro, Argentina; Ana Abarzua [[email protected]] Instituto de Ciencias de la Tierra, Facultad de Ciencias, Universidad Austral de Chile, Av. Rector Eduardo Morales Miranda 23, Valdivia 5090000, Región de los Ríos, Chile; Peter Wilf [[email protected]] Department of Geosciences, Pennsylvania State University, University Park, PA 16802, USA. *Also affiliated with: School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia. Received 28.2.2018; revised 22.8.2018; accepted 24.8.2018.
AB - A new podocarpaceous conifer is described from the early Danian Salamanca Formation (southern Chubut, Patagonia, Argentina) based on compressions of leafy branches with cuticular remains. Kirketapel salamanquensis gen. et sp. nov. has amphistomatic, scale-like leaves with marginal frills distinguishable at the apex; stomata oriented randomly in relation to the major axis of the leaf with four to five subsidiary cells and extremely reduced Florin rings; and irregularly shaped epidermal cells. We compare K. salamanquensis with extant and extinct members of the imbricate-leaved podocarps, among which it closely resembles Florin’s Dacrydium group C genera (i.e., Lagarostrobos, Manoao, Lepidothamnus and Halocarpus). Among these genera, only Lepidothamnus has a living representative in South America, the Chilean L. fonkii, whose leaf macro- and micromorphological characters are described in detail for comparison. Overall, the Patagonian fossil species is most similar to the extant and extinct members of Lagarostrobos in its cuticular micromorphology; however, macromorphological characters, such as the leaf size, apex curvature and mode of flattening, clearly differentiate it from all four genera of Dacrydium group C. We include Kirketapel salamanquensis in a combined molecular and morphological phylogenetic analysis conducted under the maximum parsimony criterion. The new, early Paleocene fossil taxon is confidently recovered as part of the scale-leaved clade as defined herein, which also includes Halocarpus, Phyllocladus, Lepidothamnus, Parasitaxus, Lagarostrobos and Manoao, and it constitutes the oldest record known for the group by at least 17 million years as well as its first fossil occurrence outside Australasia, establishing a widespread Gondwanan history. Furthermore, based on its oldest locality of occurrence, K. salamanquensis shows that the divergence of the total group of the scale-leaved podocarps occurred by at least 65 million years ago, adding to the growing systematic knowledge of earliest Cenozoic macrofloras in the Southern Hemisphere. Ana Andruchow-Colombo [[email protected]] and Ignacio Escapa [[email protected]] CONICET, Museo Paleontológico Egidio Feruglio Av. Fontana 140, Trelew 9100, Chubut, Argentina; Raymond J. Carpenter* [[email protected]] School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tas. 7001, Australia; Robert S. Hill [[email protected]] School of Biological Sciences and Environment Institute, University of Adelaide, Adelaide, SA 5005, Australia; Ari Iglesias [[email protected]] CONICET, Instituto de Investigaciones en Biodiversidad y Medioambiente INIBIOMA-CONICET, Universidad Nacional del COMAHUE, Quintral 1250, San Carlos de Bariloche 8400, Río Negro, Argentina; Ana Abarzua [[email protected]] Instituto de Ciencias de la Tierra, Facultad de Ciencias, Universidad Austral de Chile, Av. Rector Eduardo Morales Miranda 23, Valdivia 5090000, Región de los Ríos, Chile; Peter Wilf [[email protected]] Department of Geosciences, Pennsylvania State University, University Park, PA 16802, USA. *Also affiliated with: School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia. Received 28.2.2018; revised 22.8.2018; accepted 24.8.2018.
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U2 - 10.1080/03115518.2018.1517222
DO - 10.1080/03115518.2018.1517222
M3 - Article
AN - SCOPUS:85057309462
SN - 0311-5518
VL - 43
SP - 127
EP - 145
JO - Alcheringa
JF - Alcheringa
IS - 1
ER -