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SU's fossil expert returns with great news from expedition in Mongolia
Author: Corporate Communication and Marketing/Korporatiewe Kommunikasie en Bemarking - Sandra Mulder
Published: 24/10/2022

​​A discovery of multiple fossil assemblages and ash deposits in the Eastern Gobi basin in Mongolia could reveal new knowledge of dinosaurs and extreme climate conditions that existed on Earth 120 to 80 million years ago.

This is according to Dr Ryan Tucker, a sedimentologist and taphonomist in the Department of Earth Sciences at Stellenbosch University. He was part of an international team of scientists led by Dr Lindsay Zanno of the North Carolina Museum of Natural History, who undertook the expedition to Mongolia. The scientists form part of the Project MADEx (Mongolian Alliance for Dinosaur Exploration), whose work focuses on finding data on climate change in Earth's deep time, especially the Cretaceous period.Bio1.jpg

Tucker cannot reveal too much information about the discovery, as much of the recovered material belongs to new species yet to be named. “But in broad strokes, we found a rather unusually large ankylosaur, a possible allosaur-type theropod, several new dromaeosaurs (raptors), along with one site locality preserving numerous eggs and egg nests – all roughly from the middle Cretaceous period. 

“We are exceedingly happy with the data discovered," he says.

During the five weeks at the Gobi site, the team surprisingly found ash beds, which have not been identified in the Eastern Gobi until now. “This will significantly improve our understanding of the temporal framework, which currently spans a possible 40 million years. With these specific ash beds, we could improve that age estimate to within 1 million years, allowing us to meaningfully compare similar dinosaurs locally and globally," Tucker says.

“The data found at the site will provide insights into what we maybe need to adapt in our present time and future. We try to compare the Mongolian fossil assemblages and ecosystems to those of Utah (USA) to test global patterns," he adds. 

Exploring the global climate crisis

The recovered fossils, ash deposits and rock material are now at various laboratories in America, Stellenbosch, and Mongolia to determine, among others, the age of the material and to analyse the climate proxies (temperature, humidity, and rainfall). The Mongolian project aims to fill knowledge gaps by exploring the impact of a global climate crisis on North-Eastern Asia's Cretaceous ecosystems.

Previous research found that the climate on Earth is impacted by the ongoing tectonic processes (the movement of land and earthquakes) or changes in the Earth's crust. Significant climate shifts in history are linked to such geological processes or changes in the Earth.theropod (meat-eating dinosaur) tooth.jpg

Recent research showed a substantial climate change 30 million years ago, during the Cretaceous period. The warming was so intense that rainforests flourished on the South Pole. During this time –dubbed the mid-Cretaceous Thermal Maximum (CTM) – Earth's inhabitants experienced environmental and climatic disruptions directly linked to Gondwana (Southern Hemisphere separated to form South America, Africa, Antarctica, and Australia) and Laurasia (North America and Eurasia became separated from the Southern continents), Tucker elaborates on how movements in the Earth's crust can cause climate change.

He states that the detrimental effects of climate change currently being felt globally can possibly be linked to natural causes and human alteration to natural processes. 

“Therefore, our team seeks to fill these knowledge gaps by exploring the impact of a global climate crisis on North-Eastern Asian Cretaceous ecosystems. If we are successful in obtaining research funds it will allow us to better understand the effects of the CTM event in the East Gobi basin of Mongolia, allowing us to capture paleoclimate environmental proxies for global comparisons in a modern or future context."

High-risk, high-reward

Tucker plans to return to Gobi next year with postgraduate students, who will benefit significantly from prospecting there. “Besides helping to explain the region's cryptic geology, they will also be prepared for a very successful and rewarding career because of the unique nature of the fieldwork and the complexity of the geology there."Thin-bedded ash horizon(the white unit).jpg

“I hope to find funding to bring the students to Mongolia next year and for many years to come; it holds such a special place in my heart now," Tucker says. 

The Mongolian project team seeks “high-risk, high-reward" areas to do the prospecting. “With the aid of historical geological maps and satellite imagery, we assess areas with good rock exposure, high relief, and lacking human modification," says Tucker. “In these areas, the risk is high not to recover any fossil material, but the reward is also high because if we find something, it is typically new to science."

The Eastern Gobi basin is such a site. According to Tucker, there is still a wealth of data to be recovered. “We have just scratched the surface, and we barely covered a fraction of the geographical area we intended to. We saw very little of what there really is."  

The other members of the Mongolian project team are Drs Junki Yoshida and Ryuji Takasaki (research associates, School of Science, Hokkaido University, Japan), Dr Tsogtbaatar Chinzorig (Institute of Paleontology, Mongolian Academy of Sciences), Dr Khishigjav Tsogtbaatar (project advisor and Director of the Institute of Paleontology, Mongolian Academy of Sciences), and Drs Celina Suarez and Marina Suarez (University of Arkansas, USA).