lunes, 15 de mayo de 2017

Los primeros "Homo" habitaron zonas áridas y de pastizales

Científicos en EE.UU. han constatado que los antepasados más antiguos del hombre actual habitaron una zona árida y de extensas llanuras cubiertas de pastizales, según revela un estudio que publica la revista Nature Ecology and Evolution.

La investigación, desarrollada por la Arizona State University (ASU), aporta los primeros datos sobre el contexto ecológico de la época en que tuvo lugar el proceso de transición del Australopiteco al Homo.

Esa evaluación arroja luz sobre el entorno del fósil del homínido hallado en 2013 por expertos de la ASU en el yacimiento Ledi-Geraru en el estado regional de Afar, en Etiopía, que, con 2,8 millones de años de antigüedad, se convirtió en el más antiguo encontrado hasta ahora del género Homo, al que pertenece el hombre actual.

El análisis de ese fósil apuntó entonces a que la divergencia de nuestro género ocurrió casi medio millón de años antes de lo que se había concluido anteriormente.

Reconstruir el medioambiente para explicar por qué

Después de este descubrimiento, expertos de la ASU han centrado su atención en la reconstrucción del medioambiente de este antepasado para tratar de explicar por qué y cuándo apareció en esa zona del continente africano.

Para ello, los paleoantropólogos usaron fósiles como si fueran “máquinas del tiempo” para recrear aquellos entornos, de manera que si los restos de animales pertenecían a jirafas o monos podían deducir que estos se alimentaban de hojas de árboles, lo que, a su vez, indicaba que esa zona era boscosa y con precipitaciones de lluvia abundantes.

Si, por el contrario, los fósiles de animales apuntaban a que pastaban hierba, como hacen, por ejemplo, los antílopes, aquellos paisajes hubiesen sido extensas áridas planicies cubiertas de hierba.

En este sentido, la comunidad científica ha sostenido desde hace tiempo que el enfriamiento global y la expansión de ambientes herbáceos sentaron las bases para los comienzos del Homo. [...]
efefuturo.com


Grassy beginning for earliest Homo | EurekAlert! 

1/2. This wildebeest fossil skull was excavated at the Ledi-Geraru research site, Ethiopia. Credit: Josh Robinson
 
Arizona State University. In 2013, an ASU research team found the oldest known evidence of our own genus, Homo, at Ledi-Geraru in the lower Awash Valley of Ethiopia. A jawbone with teeth was dated to 2.8 million years ago, about 400,000 years earlier than previously known fossils of Homo. After the discovery, attention turned to reconstructing the environment of this ancient human ancestor to understand why there and why then.

But how do you re-create specific environments from millions of years ago to understand where our ancient ancestors lived?

Paleoanthropologists use animal fossils like proxy time machines to re-create what past environments were like. If animal fossils indicate browsing on tree leaves, like giraffes and monkeys do, then they know that the environment was characterized by woody trees and significant rainfall. If the fossils suggest grazing on grass, as many antelopes do, then the environments would have been open and arid with grassy plains.

Scientists have long suggested that global cooling and the spread of grassy environments set the stage for the beginnings of Homo...

Cave fossil offers new clues about the huge hyenas that once roamed Europe


3/3. A drawing of a cave hyena near Los Aprendices cave, shown feeding on the carcass of a Spanish Ibex, inspired by the fossils found nearby the new cave hyena skeleton. Image: Saurqué et al. 2017

Nestled in the mountain slopes of northern Spain is a cave called Los Aprendices, which has been collecting bones and sediment for hundreds of thousands of years. A few years ago, scientists discovered the ancient skeleton of one of Europe's most famous Ice Age carnivores deep within this cavern: Crocuta spelaea, the cave hyena.

Remains of these extinct creatures can be found within hundreds of caves all across Europe, but most of these fossils are just bits and pieces – complete or even partial skeletons are extremely rare. But the skeleton discovered in Los Aprendices is an exception. More than 100 bones represent over half of the animal's whole body, making this the most complete cave hyena ever discovered on the Iberian Peninsula, and one of the most complete in all of Europe. Recently, these prized remains were examined by a group of Spanish researchers, offering up fresh clues about this ancient carnivore. [...] Earth Touch News / Link 2 

Incredible finds from Lincoln Eastern Bypass dig go on show


 
Experts say it may well be the largest site of its kind ever found in Lincolnshire and one of the biggest nationally.

People can now find out more about the discoveries in a display at The Collection which runs until August.

It is a pre-cursor to this year's Archaeology Week, which will take place from July 24 to 29 and will include children's games and quizzes and a talk from Ruben Lopez, site director from Network Archaeology, who is overseeing the Lincoln Eastern Bypass investigation... Lincolnshire Live

Related...

Ancient log boat discovered at Lincoln bypass archaeological dig | Lincolnshire Live

Spraying the Bronze Age log boat

A 6m long boat made from a tree trunk has been discovered by archaeologists along the route of Lincoln Eastern Bypass.

Network Archaeology Ltd, the company working on the site to provide new insights into the past, has teamed up with Lincolnshire Live to reveal more about the incredible artefacts - which include 150 Saxon skeletons.

Here, Dr Richard Moore and director Christopher Taylor continue the series with the story of the log boat that could be up to 4,000 years old…
 


A clay pot that is up to 4,000 years old has been discovered by archaeologists along the route of Lincoln Eastern Bypass.

Network Archaeology Ltd, the company working on the site to provide new insights into the past, has teamed up with Lincolnshire Live and the Lincolnshire Echo to reveal more about the incredible artefacts - which include 150 Saxon skeletons - in a series called 'Find of the Week'.

Here, Dr Richard Moore and director Christopher Taylor continue the series with the story of the urn...

 
 
A worked and polished flint axe head which was once the prized possession of someone living on the banks of the River Witham thousands of years ago is among the spectacular finds from a dig along the route of Lincoln Eastern Bypass...