Abstract Detail

Paleobotany

Jud, Nathan A [1], GANDOLFO, MARIA A [2], Iglesias, Ari [3], WILF, PETER [4].

Early Paleocene flowers confirm a deep history for Cunoniaceae in South America.

Cunoniaceae comprises 27 extant genera and roughly 300 species of tropical and southern-temperate plants. The current distribution of this family is thought to have resulted from a combination of Gondwanan vicariance and long distance dispersal, but a sparse fossil record limits our ability to test alternate hypotheses. Herein, we report the discovery of two types of cunoniaceous flowers from the early Paleocene (Danian) Salamanca and Peñas Coloradas formations in southern Chubut Province, Argentina. The first has synapomorphies of extant Schizomerieae, including the presence of narrow, incised petals and a nectary disk; however, the fossils are unusual in having a perianth that is 8-10-merous, whereas in extant species the perianth is typically 4-5(6)-merous. The second flower type has features that are typical of the core-Cunoniaceae, including Caldcluvia, Weinmannia, and several other genera. The oldest evidence of Cunoniaceae comes from the Upper Cretaceous of Antarctica, but these represent the oldest Cunoniaceae known flowers and they add to our knowledge of the diversity of Gondwanan floras right after the end-Cretaceous extinction. Together with the recently described Ceratopetalum fruits from the early Eocene of northwest Chubut, these occurrences strengthen the biogeographic connection among Patagonia, Antarctica, and Australasia during the Paleogene.

1 - Cornell University, School of Integrative Plant Sciences, Mann Library, Ithaca, NY, 14850, USA
2 - Cornell University, L. H. BAILEY HORTORIUM, 410 Mann Library Building, ITHACA, NY, 14853-4301, USA
3 - Universidad Nacional del Comahue, Instituto de Investigaciones en Biodiversidad y Ambiente INIBIOMA-CONICET, San Carlos de Bariloche, Rio Negro, Argentina
4 - Penn State Univ., 537 Deike Bldg., UNIVERSITY PARK, PA, 16802, USA

Keywords:
Cunoniaceae
Schizomerieae
Gondwana
Patagonia
Paleocene
Salamanca Formation
Peñas Coloradas Formation.

Presentation Type: Oral Paper
Session: 7, Cookson/Moseley award presentations
Location: Sundance 4/Omni Hotel
Date: Monday, June 26th, 2017
Time: 10:15 AM
Number: 7001
Abstract ID:253
Candidate for Awards:Isabel Cookson Award