Burmese amber: evidence of Gondwanan origin and Cretaceous dispersion

Abstract

Burmese amber is an extremely important source of mid-Cretaceous plant and animal remains with over 870 species of organisms, ranging from protozoa to vertebrates, described from this source. The amber mines are located on the West Burma Block that according to geologists was originally part of Gondwana. The present study introduces some angiosperms and insects in Burmese amber whose closest extant relatives have a Gondwanan distribution and there is no previous evidence of a Laurasian distribution. Based on this evidence, it is proposed that organisms in Burmese amber represent a selection of tropical to subtropical life forms that inhabited the interconnected continents of Gondwana in the Early Cretaceous. Based on the fossil record of angiosperms and their diversity in Burmese amber, the West Burma Block could not have rafted from Gondwana to SE Asia before the Early Cretaceous.

Keywords:

• Angiosperms
• Gondwana
• Burmese amber
• West Burma Block
• mid-Cretaceous

Acknowledgments

The author thanks K. L. Chambers and A. A. Legalov for discussions on Gondwanan taxa, Ian Metcalf, Anthony Barber, Naing Maw Than and Nicholas Gardiner for providing references and opinions on tectonic events, and four anonymous reviewers whose comments greatly improved the paper. Lastly, I thank my wife, Roberta, for discussions and comments on earlier drafts of the manuscript.