![\"bosque-neotropical-hace-64-millones-de-a\u00f1os\"](\"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-content\/blogs.dir\/42\/files\/396\/bosque-neotropical-hace-64-millones-de-anos.jpg\")
<\/p>\nEn el L\u00edmite K-T, es decir tras la extinci\u00f3n de los dinosaurios, comenzaron a constituirse r\u00e1pidamente los bosques neotropicales, es decir semejantes a los actuales. Con anterioridad al impacto del probable meteorito que acab\u00f3 con aquellos gigantescos animales, la estructura y composici\u00f3n de estas\u00a0formaciones boscosas calido-h\u00famedas fue muy distinta de la actual, seg\u00fan se desprende de los an\u00e1lisis pol\u00ednicos. Sin embargo, tras la enorme cat\u00e1strofe surgieron, a gran velocidad, formaciones arb\u00f3reas tropicales-h\u00famedas semejantes a las actuales, tanto en lo que respecta a su composici\u00f3n flor\u00edstica, como a la estructura de vuelo y suelo. La primera evidencia que da cuenta de estos ecosistemas se remonta al Paleoceno. Sin embargo, al parecer, atesoraban menos biodiversidad que los actuales.<\/p>\n
\u00a0<\/p>\n
Recreaci\u00f3n de un Bosque tropical tras el l\u00edmite K-T de 64 m. a. Fuente: Denver Museum of Nature and Science<\/a><\/p>\n <\/p>\n El primer yacimiento de estas caracter\u00edsticas analizado intensivamente, tras el l\u00edmite K-T, se remonta a 58 millones de a\u00f1os atr\u00e1s. Las condiciones clim\u00e1ticas eran m\u00e1s c\u00e1lidas que las actuales en 3 y 5 \u00ba C., es decir entre 30 y 32 grados de media anual, y una pluviosidad \u00a0superior a los 2,500 mm.<\/p>\n \u00a0Sin embargo, los an\u00e1lisis realizados constatan una diferencia de consideraci\u00f3n entre aquellos bosques tropicales \u201cneo-primigenios\u201d y los actuales. De acuerdo a la noticia, que abajo reproducimos de Sciencedaily<\/strong>, eran mucho menos biodiversos que los que podemos disfrutar hoy en d\u00eda<\/strong>, en aquellos escasos lugares en donde el hombre no ha metido sus manazas. Los investigadores implicados, apuntan que los f\u00f3siles de las hojas muestran hojas da\u00f1adas que \u201csugieren\u201d una herbivor\u00eda por parte de insectos generalistas, en lugar de las complejas y espec\u00edficas relaciones que pueden observarse en nuestros tiempos, \u00a0entre especies vegetales y especies m\u00e1s especialistas que viven en una estrecha interacci\u00f3n mutua.<\/p>\n Por tanto, todo parece apuntar a que, con el tiempo, aquellos \u201cescasos\u201d taxa generalistas, fueron sufriendo un proceso de especiaci\u00f3n hacia otras formas m\u00e1s especializadas, fragmentando los nichos ecol\u00f3gicos, conforme aumentaba la biodiversidad de los ecosistemas. \u00a0Se trata de un proceso l\u00f3gico, al menos si nos atenemos a los conocimientos actuales.<\/p>\n \u00a0 Recreaci\u00f3n del primer bosque del Eoceno. Fuente: The Resilient Earth<\/a><\/p>\n La nota de prensa acaba con la desiderata al uso sobre el cambio clim\u00e1tico y bla, bla, que omito aqu\u00ed, debido a que se trata de m\u00e1s de lo mismo: hip\u00f3tesis muy generales en base a precarias evidencias emp\u00edricas.<\/p>\n Debe tenerse en cuenta que, como reconocen los investigadores implicados, se trata del primer yacimiento de esta naturaleza seriamente analizado con las tecnolog\u00edas m\u00e1s novedosas. As\u00ed pues, ser\u00e1n necesarios estudios en otros lugares con vistas a averiguar si es posible que lo aqu\u00ed descrito resulta ser un patr\u00f3n general.<\/p>\n En otro post ya os informaremos sobre los primeros bosques tropicales ancestrales, es decir, previos al gran impacto meteor\u00edtico. Tiempo al tiempo, ya que hay que editar noticias para todos los gustos.\u00a0\u00a0<\/p>\n \u00a0<\/strong><\/p>\n ScienceDaily (<\/strong>Oct. 13, 2009<\/strong><\/span>)<\/span> <\/strong>\u2014 Smithsonian researchers working in Colombia’s Cerrej\u00f3n coal mine have unearthed the first megafossil evidence of a neotropical rainforest<\/strong>. Titanoboa, the world’s biggest snake, lived in this forest 58 million years ago at temperatures 3-5 C warmer than in rainforests today, indicating that rainforests flourished during warm periods<\/strong>.<\/p>\n \u00abModern neotropical rainforests, with their palms and spectacular flowering-plant diversity, seem to have come into existence in the Paleocene epoch<\/strong>, shortly after the extinction of the dinosaurs 65 million years ago,\u00bb <\/strong>said Carlos Jaramillo, staff scientist at the Smithsonian Tropical Research Institute. \u00abPollen evidence tells us that forests before the mass extinction were quite different <\/strong>from our fossil rainforest at Cerrej\u00f3n. We find new plant families, large, smooth-margined leaves and a three-tiered structure of forest floor, understory shrubs and high canopy<\/strong>.\u00bb<\/p>\n Historically, good rock exposures and concentrated efforts by paleontologists to understand the evolution of neotropical rainforests<\/strong>\u2014one of the most awe-inspiring assemblages of plant and animal life on the planet\u2014have been lacking. \u00abThe Cerrej\u00f3n mining operation is the first clear window we have to see back in time to the Paleocene, when the neotropical rainforest was first developing<\/strong>,\u00bb said Scott Wing, a paleontologist from the Smithsonian’s National Museum of Natural History.<\/p>\n Some of the more than 2,000 fossil leaves, including the compound leaves and pods of plants in the bean family and leaves of the hibiscus family are among the oldest, reliable evidence of these groups. <\/strong>This was the first time that the plant families<\/strong> Araceae, Arecaceae, Fabaceae, Lauraceae, Malvaceae and Menispermaceae, which are still among the most common neotropical rainforest families, all occurred together<\/strong>.<\/p>\n Many newcomers to modern rainforests remark that the leaves all look the same, a reasonable observation given that most have smooth margins and long \u00abdrip-tips\u00bb thought to prevent water from accumulating on the leaf surface.<\/p>\n S. Joseph Wright, senior scientist at STRI, has noted that all of the areas in the world today with average yearly temperatures greater than 28 C are too dry to support tropical rainforests. <\/strong>If tropical temperatures increase by 3 C by the end of this century as predicted in the 2007 <\/strong>report of the Intergovernmental Panel on Climate Change<\/strong>, \u00abWe’re going to have a novel climate where it is very hot and very wet<\/strong>. How tropical forest species will respond to this novel climate, we don’t know,\u00bb said Wright.<\/p>\n Based on leaf shape and the size of the cold-blooded Titanoboa, Cerrej\u00f3n rainforest existed at temperatures up to 30-32 C and rainfall averages exceeded 2500 mm per year<\/strong>.<\/p>\n But Titanoboa’s rainforest was not as diverse as modern rainforests<\/strong>. Comparison of the diversity of this fossil flora to modern Amazon forest diversity and to the diversity of pollen from other Paleocene rainforests revealed that there are fewer species<\/strong> at Cerrej\u00f3n than one would expect. Insect-feeding damage on leaves indicated that they could have been eaten by herbivores with a very general diet rather than insects specific to certain host plants<\/strong>.<\/p>\n \u00abWe were very surprised by the low plant diversity of this rainforest.<\/strong> Either we are looking at a new type of plant community that still hadn’t had time to diversify, or this forest was still recovering from the events that caused the mass extinction 65 million years ago<\/strong>,\u00bb said Wing. \u00abOur next steps are to collect and analyze more sites of the same age from elsewhere in Colombia to see if the patterns at Cerrej\u00f3n hold, and study additional sites that bracket the Cretaceous mass extinction, in order to really understand how the phenomenal interactions that typify modern rainforests came to be.\u00bb<\/p>\n This work is scheduled to be published online in the Proceedings of the <\/strong>National<\/strong> <\/strong>Academy<\/strong> of Sciences during the week of Oct. 12-16<\/strong>.<\/p>\n Adapted from materials provided by Smithsonian Tropical Research Institute<\/a>, via EurekAlert!<\/a><\/p>\n","protected":false},"excerpt":{"rendered":" En el L\u00edmite K-T, es decir tras la extinci\u00f3n de los dinosaurios, comenzaron a constituirse r\u00e1pidamente los bosques neotropicales, es decir semejantes a los actuales. Con anterioridad al impacto del probable meteorito que acab\u00f3 con aquellos gigantescos animales, la estructura y composici\u00f3n de estas\u00a0formaciones boscosas calido-h\u00famedas fue muy distinta de la actual, seg\u00fan se desprende de los an\u00e1lisis pol\u00ednicos. Sin embargo, tras la enorme cat\u00e1strofe surgieron, a gran velocidad, formaciones arb\u00f3reas tropicales-h\u00famedas semejantes a las actuales, tanto en lo que respecta a su composici\u00f3n flor\u00edstica, como a la estructura de vuelo y suelo. La primera evidencia que da cuenta de\u2026<\/p>\n","protected":false},"author":26,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0},"categories":[618,607,600],"tags":[46736,1512,46737,46654,1513,46735],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":4}},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/135759"}],"collection":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/users\/26"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/comments?post=135759"}],"version-history":[{"count":9,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/135759\/revisions"}],"predecessor-version":[{"id":135956,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/135759\/revisions\/135956"}],"wp:attachment":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/media?parent=135759"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/categories?post=135759"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/tags?post=135759"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"bosque-tropical-humedo-eoceno-fuente-the-resilient-earth\"](\"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-content\/blogs.dir\/42\/files\/396\/bosque-tropical-humedo-eoceno-fuente-the-resilient-earth.jpg\")
<\/p>\nJuan Jos\u00e9 Ib\u00e1\u00f1ez \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span><\/h3>\n
First Neotropical Rainforest Was Home Of The Titanoboa — World’s Biggest Snake<\/a><\/h2>\n