Publication Search Results

ID: 159226
Type: article
Authors: Carrillo-Briceño, Jorge D.; Sánchez, Rodolfo; Scheyer, Torsten M.; Carrillo, Juan D.; Delfino, Massimo; Georgalis, Georgios L.; Kerber, Leonardo; Ruiz-Ramoni, Dami; Birindelli, José L. O.; Cadena, Edwin-Alberto; Rincón, Aldo F.; Chavez-Hoffmeister, Martin; Carlini, Alfredo A.; Carvalho, Mónica R.; Trejos-Tamayo, Ra; Vallejo, Felipe; Jaramillo, Carlos; Jones, Douglas S.; Sánchez-Villagra, Marcelo R.
Abstract: The Pliocene–Pleistocene transition in the Neotropics is poorly understood despite the major climatic changes that occurred at the onset of the Quaternary. The San Gregorio Formation, the younger unit of the Urumaco Sequence, preserves a fauna that documents this critical transition. We report stingrays, freshwater bony fishes, amphibians, crocodiles, lizards, snakes, aquatic and terrestrial turtles, and mammals. A total of 49 taxa are reported from the Vergel Member (late Pliocene) and nine taxa from the Cocuiza Member (Early Pleistocene), with 28 and 18 taxa reported for the first time in the Urumaco sequence and Venezuela, respectively. Our findings include the first fossil record of the freshwater fishes Megaleporinus , Schizodon , Amblydoras , Scorpiodoras , and the pipesnake Anilius scytale , all from Pliocene strata. The late Pliocene and Early Pleistocene ages proposed here for the Vergel and Cocuiza members, respectively, are supported by their stratigraphic position, palynology, nannoplankton, and 86 Sr/ 88 Sr dating. Mammals from the Vergel Member are associated with the first major pulse of the Great American Biotic Interchange. In contrast to the dry conditions prevailing today, the San Gregorio Formation documents mixed open grassland/forest areas surrounding permanent freshwater systems, following the isolation of the northern South American basin from western Amazonia. These findings support the hypothesis that range contraction of many taxa to their current distribution in northern South America occurred rapidly during at least the last 1.5 million years.

ID: 159244
Type: article
Authors: Carvalho, Monica R.; Herrera, Fabiany; Gomez Marulanda, Sebastian; Martinez, Camila; Jaramillo, Carlos
Abstract: Premise of research. Melastomataceae are a diverse and primarily tropical family with a particularly sparse fossil record. Various biogeographic interpretations based on phylogenies, extant distribution, and a limited fossil record have placed the origin of the family in either Laurasia or Gondwana (eastern or western). Methodology. We describe Xystonia simonae M. Carvalho gen. et sp. nov. on the basis of fossil leaves from middle-late Paleocene deposits of the Bogota Formation in central Colombia. These leaves have a characteristic acrodromous venation pattern common among subfamily Melastomatoideae. The leaves are compared with various acrodromously veined fossils and living angiosperms to assess their natural affinities. Pivotal results. The fossil leaves described predate the earliest known occurrence of Melastomatoideae by 5-7 Myr and conflict with previous interpretations that considered Melastomatoideae as Laurasian in origin. In revising the fossil record of Melastomataceae, we reevaluated the age of Melastomaephyllum danielis Huert. to be Miocene (previously Eocene/Oligocene) using pollen obtained from the rock that contained the type specimen. Conclusions. Our findings contribute to the scant early records of Melastomataceae and show that Melastomatoideae was part of a tropical rain forest assemblage by the middle-late Paleocene. Leaf galls and other leaf damage on X. simonae evidence intense and specialized biotic interactions in the early evolution of this lineage.

ID: 159210
Type: article
Authors: Carvalho, Mónica R.; Jaramillo, Carlos; de La Parra, Felipe; Caballero-Rodríguez, Dayenari; Herrera, Fabiany; Wing, Scott; Turner, Benjamin L.; D'Apolito, Carlos; Romero-Báez, Millerlandy; Narváez, Paula; Martínez, Camila; Gutierrez, Mauricio; Labandeira, Conrad C.; Bayona, German; Rueda, Milton; Paez-Reyes, Manuel; Cárdenas, Dairon; Duque, Álvaro; Crowley, James L.; Santos, Carlos; Silvestro, Daniele
Abstract: The end-Cretaceous event was catastrophic for terrestrial communities worldwide, yet its long-lasting effect on tropical forests remains largely unknown. We quantified plant extinction and ecological change in tropical forests resulting from the end-Cretaceous event using fossil pollen (>50,000 occurrences) and leaves (>6000 specimens) from localities in Colombia. Late Cretaceous (Maastrichtian) rainforests were characterized by an open canopy and diverse plant–insect interactions. Plant diversity declined by 45% at the Cretaceous–Paleogene boundary and did not recover for ~6 million years. Paleocene forests resembled modern Neotropical rainforests, with a closed canopy and multistratal structure dominated by angiosperms. The end-Cretaceous event triggered a long interval of low plant diversity in the Neotropics and the evolutionary assembly of today's most diverse terrestrial ecosystem.

ID: 159221
Type: article
Authors: Giraldo, Alejandro; Labandeira, Conrad C.; Herrera, Fabiany; Carvalho, Mónica

ID: 151473
Type: article
Authors: Herrera, Fabiany; Carvalho, Mónica; Jaramillo, Carlos; Manchester, Steven R.
Abstract: Premise of research. Recent classifications of Anacardiaceae recognize two subfamilies, Anacardioideae and Spondioideae. Most genera within Spondioideae are still recognized for having drupes with sclerified stones that vary in locule number and germination mechanisms. Spondioid fruits have been recognized in the Cenozoic fossil record of Europe, Asia, and North America. However, they have remained elusive in the Neotropics, where today they are an important component of tropical rain forests and seasonally dry tropical forests. Here, we describe three new species of fossil endocarps related to Spondias, Dracontomelon, and Antrocaryon.Methodology. Fossil endocarps were collected from the 19–18.5 Ma (early Miocene) Cucaracha Formation, Panama Canal. The fossils were studied by physical sections, acetate peels, and X-ray microtomography. The fossil endocarps were exhaustively compared with all extant genera of Spondioideae.Pivotal results. Spondias rothwellii sp. nov. and Antrocaryon panamaensis sp. nov. are so far the earliest and best evidence of these genera in the Neotropics. Dracontomelon montesii sp. nov. extends the occurrence of this genus to the early Miocene in Central America.Conclusions. The new Cucaracha fossils reveal that Spondioideae were a significant part of the early Miocene forests in Panama. The extant natural habitats and occurrences of the newly recognized genera suggest multistratified rain forests and active biogeographical patterns for Spondioideae approximately 19 million years ago in southern Central America.

ID: 152642
Type: article
Authors: Herrera, Fabiany; Carvalho, Mónica; Wing, Scott L.; Jaramillo, Carlos; Herendeen, Patrick S.
Abstract: Leguminosae are one of the most diverse flowering-plant groups today, but the evolutionary history of the family remains obscure because of the scarce early fossil record, particularly from lowland tropics. Here, we report ~500 compression or impression specimens with distinctive legume features collected from the Cerrejón and Bogotá Formations, Middle to Late Paleocene of Colombia. The specimens were segregated into eight fruit and six leaf morphotypes. Two bipinnate leaf morphotypes are confidently placed in the Caesalpinioideae and are the earliest record of this subfamily. Two of the fruit morphotypes are placed in the Detarioideae and Dialioideae. All other fruit and leaf morphotypes show similarities with more than one subfamily or their affinities remain uncertain. The abundant fossil fruits and leaves described here show that Leguminosae was the most important component of the earliest rainforests in northern South America c. 60–58 million years ago.

ID: 148511
Type: article
Authors: Carvalho, Mónica; Losada, Juan M.; Niklas, Karl J.
Abstract: The survival of all vascular plants depends on phloem and xylem, which comprise a hydraulically coupled tissue system that transports photosynthates, water, and a variety of other molecules and ions. Although xylem hydraulics has been extensively studied, until recently, comparatively little is known quantitatively about the phloem hydraulic network and how it is functionally coupled to the xylem network, particularly in photosynthetic leaves. Here, we summarize recent advances in quantifying phloem hydraulics in fully expanded mature leaves with different vascular architectures and show that (1) the size of phloem conducting cells across phylogenetically different taxa scales isometrically with respect to xylem conducting cell size, (2) cell transport areas and lengths increase along phloem transport pathways in a manner that can be used to model Münch's pressure-flow hypothesis, and (3) report observations that invalidate da Vinci's and Murray's hydraulic models as plausible constructs for understanding photosynthate transport in the leaf lamina.

ID: 144440
Type: article
Authors: Carvalho, Mónica R.; Turgeon, Robert; Owens, Thomas; Niklas, Karl J.

ID: 134028
Type: article
Authors: Martínez, Camila; Carvalho, Mónica R.; Madriñán, Santiago; Jaramillo, Carlos A.
Abstract: • Premise of the study: Documented fossil floras in the neotropics are sparse, yet their records provide evidence on the spatial and temporal occurrence of taxa, allowing for testing of biogeographical and diversification scenarios on individual lineages. A new fossil Piper from the Late Cretaceous of Colombia is described here, and its importance for assessing diversification patterns in the genus is addressed. • Methods: Leaf architecture of 32 fossil leaf compressions from the Guaduas Formation was compared with that of 294 extant angiosperm species. The phylogenetic position of the fossil named Piper margaritae sp. nov. was established based on leaf traits and a molecular scaffold of Piper. The age of the fossil was independently used as a calibration point for divergence time estimations. • Key results: Natural affinities of P. margaritae to the Schilleria clade of Piper indicate that the genus occurred in tropical America by the Late Cretaceous. Estimates of age divergence and lineage accumulation reveal that most of the extant diversity of the genus accrued during the last ∼30 Myr. • Conclusions: The recent radiation of Piper is coeval with both the Andean uplift and the emergence of Central America, which have been proposed as important drivers of diversity. This pattern could exemplify a recurrent theme among many neotropical plant lineages.

ID: 120922
Type: article
Authors: Carvalho, Mónica R.; Wilf, Peter; Barrios, Hector; Windsor, Donald M.; Currano, Ellen D.; Labandeira, Conrad C.; Jaramillo, Carlos A.

ID: 133124
Type: article
Authors: Herrera, Fabiany; Manchester, Steven R.; Carvalho, Mónica R.; Jaramillo, Carlos A.; Wing, Scott L.

ID: 116840
Type: article
Authors: Carvalho, Mónica R.; Wilf, Peter; Hermsen, Elizabeth J.; Gandolfo, Maria A.; Cúneo, N. Rubén; Johnson, Kirk R.
Abstract: o Premise of the Study: The early Eocene Laguna del Hunco caldera-lake paleoflora (ca. 52 Ma) from Chubut Province, Argentina, is notably diverse and includes many conifer and angiosperm lineages that are extinct in South America but extant in Australasian rainforests. No ferns have been previously described from Laguna del Hunco. We describe and interpret a new species of fossil Osmundaceae based on fertile and sterile pinnae. o Methods: The fossil specimens were compared with other extant and fossil Osmundaceae based on living and herbarium material and published descriptions. A morphological matrix based on 29 characters was constructed for 17 living species in Osmundaceae, four species assigned to the fossil genus Todites, and the new fossil species. Phylogenetic analyses were conducted under parsimony using morphology and total evidence matrices. o Key Results: Both the new fossil and the Todites species were consistently resolved within the leptopteroid clade of Osmundaceae, and the new species resolved in a clade with the two living Todea species, which are now restricted to Australia, New Guinea, New Zealand, and southern Africa. o Conclusions: Todea amissa sp. nov. is the first record of Todea, living or fossil, in South America and only the second fossil record worldwide. The distribution of extant Todea on Gondwanan continents other than South America is broadly shared with other taxa from Laguna del Hunco, further indicating that a large component of this flora represents a Gondwanic biome that is no longer found on the South American continent.

ID: 111450
Type: article
Authors: Guisande, Cástor; Pelayo-Villamil, Patricia; Vera, Manuel; Manjarrés-Hernández, Ana; Carvalho, Mónica R.; Vari, Richard P.; Jiménez, Lus F.; Fernández, Carlos; Martínez, Paulino; Preto-Piraquive, Edgar; Granado-Lorencio, Carlos

ID: 101916
Type: article
Authors: Carvalho, Mónica R.; Herrera, Fabiany; Jaramillo, Carlos A.; Wing, Scott L.; Callejas, Ricardo

ID: 108670
Type: article
Authors: Herrera, Fabiany; Manchester, Steven R.; Hoot, Sara B.; Wefferling, Keir M.; Carvalho, Mónica R.; Jaramillo, Carlos A.