Ancient Indian Amber Preserves 52-million-year-old Biological Partnership main content.

Ancient Indian Amber Preserves 52-million-year-old Biological Partnership

by AMNH on

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Ectomycorrhizae in Indian amber. 
© Alexander Schmidt, University of Göttingen.

A rare fossil discovered by an international team of scientists that includes Museum researchers documents a biological partnership that makes the survival of most terrestrial plants possible. For 52 million years in a piece of Indian amber the size of a walnut, the fossil preserved a symbiotic relationship between soil fungi and plant roots called mycorrhizae.

In this longstanding relationship, the fine thread-like cells of the fungus increase the root surface for the plant, enabling the host plant to access more nutrients. In return, the fungus receives energy from the plant in the form of sugars. This symbiosis also has been shown to enhance a plant’s resistance to pathogens and the effects of drought. This mycorrhizal relationship is believed to have arisen more than 400 million years ago, as plants began to colonize terrestrial habitats.

There are two primary types of mycorrhizae: endomycorrhizae, found in more than 80 percent of all plant species studied, and ectomycorrhizae, which occurs in roughly 10 percent of plant species.

Scanning electron micrograph of fossil ectomycorrhiza leached out of the amber fragment.
© Alexander Schmidt, University of Göttingen.

Paul Nascimbene of the American Museum of Natural History’s Division of Invertebrate Zoology is part of a research team led by Alexander Schmidt from Göttingen University in Germany that has discovered the first fossil ectomycorrhizae associated with flowering plants. Details about the fossil, which was found in a piece of Indian amber and was formed just 13 million years after the demise of dinosaurs, are published in the December issue of the journal New Phytologist. The fossil inclusions show various stages of development and reveal a variety of morphological details.

For more details, see the Museum’s press release.