Oldest Known Eucalyptus Macrofossils Are from South America
Author Information
Author(s): Gandolfo María A., Hermsen Elizabeth J., Zamaloa María C., Nixon Kevin C., González Cynthia C., Wilf Peter, Cúneo N. Rubén, Johnson Kirk R.
Primary Institution: L.H. Bailey Hortorium, Department of Plant Biology, Cornell University
Hypothesis
The study investigates the evolutionary history and geographical distribution of Eucalyptus based on fossil evidence.
Conclusion
The fossils indicate that Eucalyptus evolved outside of Australasia, specifically in early Eocene South America.
Supporting Evidence
- The fossils include leaves, flower buds, and fruits that show morphological similarities to extant Eucalyptus.
- The fossils are the only illustrated Eucalyptus fossils definitively dated to the Eocene.
- Phylogenetic analyses suggest that the fossils are nested within the Eucalyptus clade.
- The fossils indicate that Eucalyptus subgenus Symphyomyrtus is older than previously thought.
- Paleoecological data suggest that Eucalyptus dominated disturbed areas adjacent to rainforest.
Takeaway
Scientists found very old Eucalyptus fossils in South America, showing that these trees used to grow there a long time ago.
Methodology
The study involved collecting and analyzing fossil specimens from the Laguna del Hunco paleoflora and conducting phylogenetic analyses.
Limitations
The fossil record of Eucalyptus is sparse, and the study relies on morphological and molecular data that may not fully capture the evolutionary history.
Digital Object Identifier (DOI)
Want to read the original?
Access the complete publication on the publisher's website