Paleontologists Discover First Fossils of Extant Tropical Tree Species

Fossils of the giant rainforest tree Dryobalanops rappa have been found in Brunei (officially known as Brunei Darussalam), an island nation in Borneo. This discovery marks the first fossil evidence of a living, endangered tropical tree species, opening up new avenues for fossil research and underscoring the importance of Southeast Asian heritage and its preservation.

Locally referred to as Kapur Paya, Dryobalanops rappa is a tall tree species that exists today but is threatened with extinction in Borneo’s carbon-rich peatlands, including Brunei.

Fossil leaves estimated to be 2 million years old were uncovered in Kampong Rugh within the Chuton district of Brunei.

“This discovery provides a unique glimpse into the ancient history of Asian tropical wet forests,” noted researchers from Pennsylvania.

“We now have fossil evidence that this remarkable tree species has been integral to Borneo’s forests for millions of years, emphasizing its ecological significance and the urgency to protect its remaining habitats.”

According to Professor Peter Wilf of Pennsylvania, “Fossil records of wet tropical forests in Asia have been surprisingly limited compared to those in the Amazon and Africa.”

Paleontologists identified these fossils by examining the microscopic features of the preserved leaf cuticles, down to the cellular level of Dryobalanops rappa.

“Our findings underscore that these forests are not only thriving with biodiversity today but are also home to iconic tree species that have existed for millions of years,” Wang stated.

“Conservation efforts should not only focus on current species but also aim to preserve the ecological legacy that has endured over millennia.”

“The dominant tree family in Asian rainforests, the bi-pterocarps, plays a crucial role in carbon storage and biodiversity,” the researchers highlighted.

“However, these trees face increasing threats from deforestation and habitat loss.”

“By unveiling the deep historical roots of these trees, this discovery offers a fresh perspective on conservation strategies,” Wang added.

“These findings add a new dimension to conservation, as we strive to protect not only modern species but also ancient survivors that are pivotal to our ecosystem,” Wang concluded.

“This historical context makes both the endangered tree species and their habitats even more critical for conservation efforts.”

“Our research demonstrates how fossil evidence can inform conservation strategies for endangered species and ecosystems, grounded in their historical importance,” Professor Wilf remarked.

“Understanding the history of tropical forests is vital for conservation, especially as numerous key species face rapid decline.” Professor Wilf emphasized.

“Our discovery lays an essential historical foundation for the conservation of keystone trees in tropical Asia, particularly the rapidly diminishing bi-ptery species.”

Details of these findings are documented in a paper published in the American Journal of Botany.

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Teng-Xiang Wang et al. Fossils of the endemic giant dual-pterocarp species open a historic portal into Borneo’s disappearing rainforest. American Journal of Botany, published online on May 8, 2025. doi:10.1002/ajb2.70036