AMERICAN JOURNAL OF BotanyDecember 2011 ◆ Volume 98 ◆ Number 12 Vol. 98, No. 12, 1911–xxxx—AMERICAN JOURNAL OF BOTANY—DECEMBER 2011 12, 1911–xxxx—AMERICAN JOURNAL OF BOTANY—DECEMBER 98, No. Vol. Offi cial Publication of the Botanical Society of America, Inc. www.amjbot.org American Journal of Botany 98(12): 2004–2017. 2011. P HYTOGEOGRAPHIC IMPLICATIONS OF FOSSIL ENDOCARPS OF MENISPERMACEAE FROM THE PALEOCENE OF COLOMBIA 1 Fabiany Herrera 2,3,6 , Steven R. Manchester2 , Sara B. Hoot 4 , Keir M. Wefferling 4 , M ó nica R. Carvalho 3,5 , and Carlos Jaramillo 3 2 Department of Biology – Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611 USA; 3 Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Balboa, Anc ó n, Rep ú blica de Panam á ; 4 Department of Biological Sciences, P. O. Box 413, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201 USA; and 5 Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania 16802 USA • Premise of the study: Fossil leaves of Menispermaceae were previously described from the Paleocene of Colombia. Because of strong homoplasy of leaf characters, the fossils could not be placed more specifi cally within recognized clades, and additional data were needed to specify intrafamilial and paleogeographic relationships during the Paleocene. • Methods: Fossil endocarps of Menispermaceae were collected from the Cerrej ó n Formation, the recently discovered Bogot á fl ora, and Wyoming (~60 Ma). We surveyed the endocarp morphology of almost all extant genera, conducted character optimization, a molecular scaffold analysis, and critically reviewed the related fossil genera. • Key results: Parallel syndromes of fruit characters have appeared in unrelated clades of the family according to current phylo- genetic reconstructions. However, mapping selected endocarp characters across those clades that contain horseshoe-shaped endocarps facilitates identifi cation and phylogenetic assessment of the fossils. Three fossil species are recognized. One of them belongs to the extant genus Stephania , which today grows only in Africa and Australasia. Palaeoluna gen. nov. is placed within the pantropical clade composed of extant Stephania , Cissampelos , and Cyclea ; this morphogenus is also recognized from the Paleocene of Wyoming. Menispina gen. nov. shows similarity with several unrelated clades. • Conclusions: The new fossils from Colombia reveal a complex paleobiogeographic history of the recognized clades within Menispermaceae, suggesting a more active exchange among neotropical, paleotropical, North American, and European paleo- forests than previously recognized. In addition, the new fossils indicate that neotropical forests were an important biome for the radiation and dispersal of derived lineages in Menispermaceae after the Cretaceous – Paleogene boundary. Key words: Cissampelos ; Colombia; endocarps; fossils; paleobiogeography; Paleocene; rainforest; Stephania . Menispermaceae are a pantropical angiosperm family within family include liana or vine growth habit, fl owers unisexual, Ranunculales with approximately 71 genera and 450 – 500 spe- plants usually dioecious, petioles often swollen at the base, cies ( Thanikaimoni, 1984 ; Kessler, 1993 ). Species of the family ovules two (but one aborting), fruits in aggregates of drupes, are most common in tropical lowland rainforests although sev- endocarps with a condyle and seeds with a large, usually curved eral genera have species adapted to cooler or drier biomes. embryo ( Diels, 1910 ; Kessler, 1993 ; Ortiz et al., 2007 ; Hoot Some of the morphological synapomorphies recognized for the et al., 2009 ; Jacques, 2009a ). Historically, Menispermaceae were divided into fi ve or eight tribes based largely on endocarp and seed characters ( Miers, 1 Manuscript received 15 November 2010; revision accepted 12 September 1851 ; Diels, 1910 ; Kessler, 1993 ). However, the recent boom in 2011. molecular analyses has resulted in revised hypotheses of tribal This research was made possible through support from the Evolving relationships, morphological evolution, and classifi cation for Earth Foundation, the Geological Society of America Foundation, the this family ( Jacques et al., 2007 , 2011 ; Ortiz et al., 2007 ; Wang Asociaci ó n Colombiana de Ge ó logos y Geof í sicos del Petroleo-ARES, et al., 2007 ; Jacques and Bertolino, 2008 ; Hoot et al., 2009 ). The The Smithsonian Institution, the Gary S. Morgan Student Research Award, endocarp types (i.e., boat-shaped, horseshoe-shaped, hairpin- and the Lewis & Clark Foundation-American Philosophical Society to F.H., National Science Foundation (NSF) grants EF-0431266 and BSR- shaped) that were used for the traditional classifi cation within 0743474 to S.R.M., NSF DEB-0919071 to M.R.C., NSF DEB-0733725 to the family appear to be highly homoplasious, and several tradi- C.J., and NSF DEB-0542679 to S.B.H. The authors thank L. Teicher, F. tional tribes and genera based on these characters are poly- Chavez, and the geology team at Minas Cerrej ó n. J. Moreno, E. Cadena, A. phyletic or paraphyletic when superimposed on a molecular Rincon, S. Moron, G. Bayona, S. L. Wing, J. Bloch, M. I. Barreto, G. phylogeny ( Jacques et al., 2007 ; Ortiz et al., 2007 ; Hoot et al., Doria, and A. Rojas for their assistance with the Bogot á and Cerrej ó n fi eld 2009 ). These new hypotheses of intrafamilial relationships trips; C. A. Mu ñ oz for his hospitality during fi eldwork in Bogot á . D. Bell in Menispermaceae indicate the need for caution in identifying (US) granted access to modern Menispermaceae collections, R. C. Ortiz affi nities for fossil taxa. Nonetheless, fossil endocarps are in- and F. Jacques provided helpful discussions about the systematics of the valuable for understanding the evolution and paleobiogeography fossils, and G. Bedoya provided nomenclatural suggestions. Two of the family. Furthermore, their identifi cation to the tribe or ge- anonymous reviewers and T. Lott provided helpful reviews of the manuscript. F.H. thanks B. Himschoot for support. nus level will require a combination of fruit characters instead of 6 Author for correspondence (e-mail: fherrera@fl mnh.ufl .edu) relying on the historical endocarp types ( Jacques et al., 2011 ). As recently listed in Doria et al. (2008) and Jacques (2009b) , doi:10.3732/ajb.1000461 dozens of leaf, wood, fl ower, pollen, and endocarp fossils American Journal of Botany 98(12): 2004–2017, 2011; http://www.amjbot.org/ © 2011 Botanical Society of America 2004 December 2011] Herrera et al. — Fossil endocarps of Menispermaceae from South America 2005 have been attributed to Menispermaceae ranging from the Formation had accumulated in the lowlands ( Bayona et al., 2008 ). Pollen as- lower Cretaceous to the Pliocene. In South America, Paleo- semblages from the Bogot á Formation belong to the zone T-03b- Foveotricol- pites perforatus of Jaramillo et al. (2011) , indicating a middle to late Paleocene gene fossil leaves have been attributed to Menispermaceae age. The formation varies from extensive and thick siltstones, claystones, and from the Paleocene of Colombia and Argentina ( Iglesias et al., paleosols to interbedded sandstones and sporadic conglomerates and breccias. 2007 ; Doria et al., 2008 ) and the Eocene of Brazil ( Dolianiti, Contrary to the Cerrej ó n Formation, the Bogot á sequence lacks coal deposits. 1949 ; Mello et al., 2000 ). Of these fossil records, just those Initial sedimentological analyses from the Bogot á Formation indicate deposi- reported from the Paleocene of Colombia ( Doria et al., 2008 ) tion in fl uvial environments. The specimen BF18-ING-0017 was found in a have been fully described and compared with extant leaves of massive yellowish lacustrine claystone bed, about 40 cm thick underneath a thick red paleosol. The specimens BF19-ING-0012-0016 and BF18-ING-0023 the family; the remaining reports of Menispermaceae in South are from grayish, laminated, and fi ne-grained sandstones that suggest deposi- America still require a detailed examination to confi rm their tion in overbank deposits. The specimens BF20-ING-0019-0020, BF20- affi nity. Because of the homoplasy found in leaf characters in ING-0024, and BF20-ING-0026 were found along with abundant crocodile Menispermaceae (see Hoot et al., 2009 ), the four Paleocene teeth and turtle shells in an ~20 cm reddish breccia with very angular grains and fossil species from the Cerrej ó n Formation of Colombia could iron oxide cementing material. This bed may have been deposited during an not be placed more specifi cally within recognized clades of aqueous debris fl ow. Some of the plant families and genera already identifi ed from the Bogot á fl ora include Annonaceae, Arecaceae, Fabaceae, Lauraceae, the family ( Doria et al., 2008 ). Future comparative studies on Malvaceae, Salicaceae, Theaceae, and the fl oating-aquatic fern Salvinia . cuticle and leaf architectural patterns among living Menisper- The Colombian fossils are stored at the paleontological collections of the maceae might provide stronger evidence for placing such Colombian Geological Institute (INGEOMINAS) in Bogot á , Colombia. fossils. The specimen from Linch, Wyoming (UF18257-21872; Fig. 17 ) was recov- Jacques et al. (2011) recently used a molecular scaffold ered from a Paleocene (Tiffanian) locality of the Fort Union Formation (Pow- analysis for the placement of 26 taxa of fossil menisperma- der River Basin), exposed at the west side of the highway 192 at the southern end of the road