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 Geochemists measure new composition of Earth’s mantle
17.09.2019 | Westfälische Wilhelms-Universität Münster

nachricht Low sea-ice cover in the Arctic
13.09.2019 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: 'Nanochains' could increase battery capacity, cut charging time

How long the battery of your phone or computer lasts depends on how many lithium ions can be stored in the battery's negative electrode material. If the battery runs out of these ions, it can't generate an electrical current to run a device and ultimately fails.

Materials with a higher lithium ion storage capacity are either too heavy or the wrong shape to replace graphite, the electrode material currently used in...

Im Focus: Stevens team closes in on 'holy grail' of room temperature quantum computing chips

Photons interact on chip-based system with unprecedented efficiency

To process information, photons must interact. However, these tiny packets of light want nothing to do with each other, each passing by without altering the...

Im Focus: Happy hour for time-resolved crystallography

Researchers from the Department of Atomically Resolved Dynamics of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg, the University of Hamburg and the European Molecular Biology Laboratory (EMBL) outstation in the city have developed a new method to watch biomolecules at work. This method dramatically simplifies starting enzymatic reactions by mixing a cocktail of small amounts of liquids with protein crystals. Determination of the protein structures at different times after mixing can be assembled into a time-lapse sequence that shows the molecular foundations of biology.

The functions of biomolecules are determined by their motions and structural changes. Yet it is a formidable challenge to understand these dynamic motions.

Im Focus: Modular OLED light strips

At the International Symposium on Automotive Lighting 2019 (ISAL) in Darmstadt from September 23 to 25, 2019, the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, a provider of research and development services in the field of organic electronics, will present OLED light strips of any length with additional functionalities for the first time at booth no. 37.

Almost everyone is familiar with light strips for interior design. LED strips are available by the metre in DIY stores around the corner and are just as often...

Im Focus: Tomorrow´s coolants of choice

Scientists assess the potential of magnetic-cooling materials

Later during this century, around 2060, a paradigm shift in global energy consumption is expected: we will spend more energy for cooling than for heating....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Optical Technologies: International Symposium „Future Optics“ in Hannover

19.09.2019 | Event News

Society 5.0: putting humans at the heart of digitalisation

10.09.2019 | Event News

Interspeech 2019 conference: Alexa and Siri in Graz

04.09.2019 | Event News

 
Latest News

Quality control in immune communication: Chaperones detect immature signaling molecules in the immune system

20.09.2019 | Life Sciences

Moderately Common Plants Show Highest Relative Losses

20.09.2019 | Life Sciences

The Fluid Fingerprint of Hurricanes

20.09.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>