Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

An Ice Age savannah corridor let large mammals spread across Southeast Asia

22.08.2019

Tübingen research team finds evidence of an open landscape through which animals and people could walk to today’s Indonesian islands

New research from the University of Tübingen indicates that the Thai-Malay Peninsula – where parts of Malaysia, Myanmar and Thailand are located – was at least partly an open savannah during the Ice Age, when the peninsula was part of a much larger land now known as the Sunda Shelf.


Paleoenvironments in Peninsular Thailand where extinct species of the spotted hyena lived during the past 100,000 years.

Kantapon Suraprasit, University of Tübingen


A mandible of the Javan rhinoceros (Rhinoceros sondaicus) in situ during excavations at Yai Ruak Cave, Thailand.

Kantapon Suraprasit, University of Tübingen

It is likely to have provided a corridor for large mammals from mainland Asia to reach today's islands of Sumatra, Borneo and Java for the first time, between 120,000 and 70,000 years ago. That is the conclusion reached by Dr. Kantapon Suraprasit, a Humboldt Research Fellow at the University of Tübingen and a lecturer at Chulalongkorn University (Thailand), and Professor Hervé Bocherens of the Senckenberg Centre for Human Evolution and Palaeoenvironment at the University of Tübingen, working with other Thai researchers.

The team carried out isotope analyses on the teeth of Ice Age mammals found on excavations in the region. Scientists have long hotly debated how animals and early humans migrated between the mainland and the islands of Southeast Asia. These latest findings strengthen the hypothesis that a savannah corridor existed during the Ice Age, giving humans and animals relatively easy passage to the south and east from mainland Asia. The study has been published in Quaternary Science Reviews.

... more about:
»Shelf »fossils »hyenas »isotope »mammals »savannah

The Yai Ruak Cave, located in Thailand’s Krabi Province, was excavated in 2017 by a team of Thai paleontologists from Chulalongkorn University and the Department of Mineral Resources (Bangkok), with the help of local people. In the cave sediments, the excavators found some near-complete lower jaw bones, individual teeth and bones.

The fossils were of the Malay porcupine, the Javan rhinoceros, the Sambar deer and extinct relatives of the spotted hyena. “This is the southernmost evidence found in Southeast Asia of this kind of hyena,” says Hervé Bocherens. This supports the hypothesis that in the Pleistocene, mammals were able to spread further south.

Because sea levels were much lower during the Ice Age, today’s islands of Sumatra, Borneo and Java on the Sunda Shelf were connected by land bridges. Although human fossils were not found in the cave, anatomically modern humans may have been present in the area at that time, the researchers say.

Diverse ecosystems

Kantapon Suraprasit carried out carbon and oxygen isotope analyses on the tooth enamel of all the animal species found in the Yai Ruak cave, at the University of Tübingen’s biogeology laboratory. Isotopes are atoms of the same chemical element with different weights. From their frequency distribution – or isotope signature – scientists can draw conclusions about the type of food an animal ate and the environmental conditions during its lifetime.

“The region where the fossils were found is now covered by rainforests. We were therefore surprised that the isotope signatures from the teeth of the spotted hyenas and Sambar deer indicate an open grassland,” says Suraprasit.

But the teeth of the Javan rhinoceros and the porcupines produced isotopic signatures that match forests, Suraprasit says. He concludes that there were several different ecosystems in the area – including an open landscape. "These results confirm that a savannah corridor existed at that time along the tropical monsoon regions, stretching to the south of what is now Thailand, as far as the latitude of the previously exposed Sunda Shelf," says Hervé Bocherens.

Barrier rainforests

Of all the animals migrating south while sea levels were lower, the grassland-loving hyena may have been one of the few to be put off by a rainforest belt which curved from northern Sundaland across today’s Borneo and Sumatra, crossing the savannah corridor. To date, no fossils of spotted hyenas have been found south of the Yai Ruak cave.

"There were likely dense rainforests that formed a barrier. At that time, the hyenas could not go further south to the lands which are now islands, but other Yai Ruak mammal species and possibly humans could," Bocherens explains. Pollen analyses indicate closed forest vegetation from Sumatra to Borneo back then, as well as on parts of the Malay Peninsula.

The research team hopes that the ongoing excavations at Yai Ruak cave will provide more information in the future about these diverse ecosystems and their influence on the faunas of the Southeast Asian mainland and the islands.

Wissenschaftliche Ansprechpartner:

Professor Dr. Hervé Bocherens
University of Tübingen
Department of Geosciences – Biogeology
Senckenberg Center for Human Evolution and Palaeoenvironment
Phone +49 7071 29-76988
herve.bocherens[at]uni-tuebingen.de

Dr. Kantapon Suraprasit
Alexander von Humboldt Fellow
University of Tübingen
Department of Geosciences – Biogeology
Phone +49 7071 29-72493
Suraprasit[at]gmail.com

Originalpublikation:

Kantapon Suraprasit, Sutee Jongautchariyakul, Chotima Yamee, Cherdchan Pothichaiya, and Hervé Bocherens: New fossil and isotope evidence for the Pleistocene zoogeographic transition and hypothesized savanna corridor in Peninsular Thailand. Quaternary Science Reviews, https://doi.org/10.1016/j.quascirev.2019.105861

Dr. Karl Guido Rijkhoek | idw - Informationsdienst Wissenschaft
Further information:
https://uni-tuebingen.de

Further reports about: Shelf fossils hyenas isotope mammals savannah

More articles from Earth Sciences:

nachricht Shrinking of Greenland's glaciers began accelerating in 2000, research finds
11.12.2019 | Ohio State University

nachricht One-third of recent global methane increase comes from tropical Africa
11.12.2019 | European Geosciences Union

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Highly charged ion paves the way towards new physics

In a joint experimental and theoretical work performed at the Heidelberg Max Planck Institute for Nuclear Physics, an international team of physicists detected for the first time an orbital crossing in the highly charged ion Pr⁹⁺. Optical spectra were recorded employing an electron beam ion trap and analysed with the aid of atomic structure calculations. A proposed nHz-wide transition has been identified and its energy was determined with high precision. Theory predicts a very high sensitivity to new physics and extremely low susceptibility to external perturbations for this “clock line” making it a unique candidate for proposed precision studies.

Laser spectroscopy of neutral atoms and singly charged ions has reached astonishing precision by merit of a chain of technological advances during the past...

Im Focus: Ultrafast stimulated emission microscopy of single nanocrystals in Science

The ability to investigate the dynamics of single particle at the nano-scale and femtosecond level remained an unfathomed dream for years. It was not until the dawn of the 21st century that nanotechnology and femtoscience gradually merged together and the first ultrafast microscopy of individual quantum dots (QDs) and molecules was accomplished.

Ultrafast microscopy studies entirely rely on detecting nanoparticles or single molecules with luminescence techniques, which require efficient emitters to...

Im Focus: How to induce magnetism in graphene

Graphene, a two-dimensional structure made of carbon, is a material with excellent mechanical, electronic and optical properties. However, it did not seem suitable for magnetic applications. Together with international partners, Empa researchers have now succeeded in synthesizing a unique nanographene predicted in the 1970s, which conclusively demonstrates that carbon in very specific forms has magnetic properties that could permit future spintronic applications. The results have just been published in the renowned journal Nature Nanotechnology.

Depending on the shape and orientation of their edges, graphene nanostructures (also known as nanographenes) can have very different properties – for example,...

Im Focus: Electronic map reveals 'rules of the road' in superconductor

Band structure map exposes iron selenide's enigmatic electronic signature

Using a clever technique that causes unruly crystals of iron selenide to snap into alignment, Rice University physicists have drawn a detailed map that reveals...

Im Focus: Developing a digital twin

University of Texas and MIT researchers create virtual UAVs that can predict vehicle health, enable autonomous decision-making

In the not too distant future, we can expect to see our skies filled with unmanned aerial vehicles (UAVs) delivering packages, maybe even people, from location...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The Future of Work

03.12.2019 | Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

 
Latest News

Self-driving microrobots

11.12.2019 | Materials Sciences

Innovation boost for “learning factory”: European research project “SemI40” generates path-breaking findings

11.12.2019 | Information Technology

Molecular milk mayonnaise: How mouthfeel and microscopic properties are related in mayonnaise

11.12.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>