Media release

From: SMC Taiwan

A study by research teams at the National Museum of Natural Science and National Taiwan University has, for the first time, unveiled Taiwan's vanished Pleistocene ecosystem: a warm, arid savannah environment dominated by grasslands and rivers. This breakthrough palaeontological finding is set for publication in Royal Society Open Science on November 5th.

Dr. Chun-Hsiang Chang, a researcher at the National Museum of Natural Science, reported that stable carbon isotope analysis of the Straight-tusked Elephant (Palaeoloxodon) enamel showed the animals subsisted on C4 plants—herbaceous plants using the C4 photosynthetic pathway—almost year-round. This diet is strikingly different from the C3-preferring Palaeoloxodon in Europe and Japan, which favour environments typically associated with forests or temperate zones. Instead, their dietary profile closely resembles that of Palaeoloxodon species in India and Africa, which were adapted to tropical or subtropical grassland habitats. This confirms that the Taiwan Strait, when exposed as part of the landmass, was a dry, warm C4 savannah, distinct from the forest landscapes currently seen on Taiwan island.

Dr. Chang emphasized that the discovery not only reconstructs the unique environment in the Far East but also reveals a pronounced dietary differentiation within the Palaeoloxodon genus across the Eurasian continent, linked to changes in latitude.

Furthermore, the elephant teeth provided palaeo-hydrological data. Professor Cheng-Hsiu Tsai of National Taiwan University explained that oxygen isotope analysis showed the Taiwanese Palaeoloxodon utilized freshwater river resources. This supports the existence of large-scale freshwater rivers flowing through the Taiwan Strait during the Pleistocene, providing concrete evidence for the ancient river system's presence.

Overall, this research is a key milestone for understanding East Asian palaeoecology, evolutionary diversity, and regional species differentiation. It not only provides the first insight into Taiwan's Pleistocene giant grassland-river valley ecosystem but also, through sequential isotope records, done by the PhD candidate Deep S. Biswas at NTU, captures the weaning behaviour of juvenile Palaeoloxodon continuing until approximately five to six years of age, significantly augmenting knowledge of these giant mammals' life history.