The newly-identified species of screw palm, named Pandanus estellae, is significant because it provides credible pre-Pleistocene evidence of the genus Pandanus.
Reconstruction of Pandanus estellae. Image credit: Alison Douglas.
Pandanus is a genus of palm-like, dioecious trees and shrubs native to the Old World tropics and subtropics.
Commonly known as pandans, screw palms, and screw pines, there are over 450 scientifically recognized species.
The greatest number of species are found in Madagascar and Malaysia.
“Our study provided evidence for Gondwana history for the genus, which had been previously missing,” said Dr. Andrew Rozefelds, a paleontologist at the Queensland Museum and the School of Engineering and Technology at the Central Queensland University.
“Understanding the evolutionary history of any group of plants or animals, can be challenging and fossils can offer unique insights into the history and past distribution of some groups.”
Fruit of Pandanus estellae. Image credit: Queensland Museum.
The new species, named Pandanus estellae, was described from a silicified fossil fruit found in the Capella region in central Queensland, Australia.
The specimen is at least 30 million years old, making it the oldest fruit of the Pandanus genus currently known.
The small size of the fruit differs from fruits of modern species in the genus, which are typically much larger.
Previously, paleontologists have suggested that the large fruits of living Pandanus species have evolved in response to long distance dispersal by ocean currents.
The small size of Pandanus estellae fruits suggests that only more localized dispersal was likely.
“While Pandanus has football-sized fruits that can measure up to 25 cm in diameter, the fossil fruits were one tenth of the size of most of the modern species occurring in Australia,” the researchers said.
“This could be important for understanding of the evolution of fruit size in the genus and the patterns of seed dispersal by the plant.”
The team’s paper was published in the International Journal of Plant Science.
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Andrew C. Rozefelds et al. 2022. A Fossil Syncarpous Fruit from Australia Provides Support for a Gondwanan History for the Screw Pines (Pandanus, Pandanaceae). International Journal of Plant Sciences 183 (4); doi: 10.1086/719431
