We are using fossils to investigate the origin and evolution of relationships between plants and microorganisms during the early development of life on land.
Our research objectives are to:
- complete a systematic survey of microscopic eukaryotes based on the Museum's fossil slide collections
- describe new microfossils using state-of-the-art imaging techniques
- determine their affinities using modern phylogenetic methods
Fungi and fungi-like eukaryotes are ancient groups thought to be vital in the early development of terrestrial ecosystems. Molecular phylogenetic studies of living species reveal their evolutionary history, but scientists also use fossils to calibrate these relationships.
Fossils provide the only direct evidence of early fungi and fungi-like microorganisms interacting with plants. Fossils are therefore crucial in defining evolutionary relationships of modern species, as they allow us to determine the beginnings of lineages.
We are collecting new data on fossil fungi and fungus-like microorganisms using:
- state-of-the-art imaging methods
- phylogenetic characters for the newly described microorganisms, to develop a phylogenetic framework that relates to modern forms.
This project is improving our understanding of the origin and evolution of key microorganism and plant associations.
- Fungi: Fungi are heterotrophic eukaryotes. They are one of the least explored biodiversity resources and their symbiotic relations are crucial to the survival of plants.
- Fungi-like microorganisms: The Oomycetes (fungi-like microorganisms) are some of the most important plant pathogens, including Potato Blight Phytophthora infestans and Ash dieback Chalara fraxinea. Although they superficially resemble fungi in mycelial growth and mode of nutrition, they show distinct characteristics. Recent research on fossils in the Museum's collection has provided the earliest evidence for parasitism in this group.
We are undertaking the Museum's first systematic study of microscopic symbionts preserved among plant tissues, based on observations of the thin section collection.
The soft tissues of fossil plants are often preserved in minerals, such as pyrite, calcite and silica. Thin sections reveal the internal structure of these specimens and contain valuable information about microscopic symbionts preserved inside.
The Museum has a large and comprehensive collection of fossil plants and a unique collection of thin sections containing over 15,000 objects.
We are sampling plant taxonomic groups for all key organ systems - roots, stems, trunks, leaves and reproductive organs.
Data is sourced from two important time slices:
- The Early Devonian Rhynie Chert, ca 410 million years old. This is the oldest terrestrial site of exceptional preservation. Plants preserved in these rocks are all small and herbaceous.
- The Late Carboniferous Coal Measures of the UK, ca 310 million years old. Terrestrial ecosystems were well established in forested wetlands during this period.
We are using three different light microscopy imaging processes to describe fungal structures, identify new forms and characterise their relationships with plants.
Newly-described species are classified based on their evolutionary development. This phylogenetic approach allows us to place organisms into a framework that can be compared to modern forms.
- Krings M, Taylor TN, Dotzler N (2011) The fossil record of the Peronosporomycota (Oomycota). Mycologia, 103(3): 445-457.
- Strullu-Derrien C, Kenrick P, Rioult JP, Strullu DG (2011) Evidence of parasitic Oomycetes (Peronosporomycetes) infecting the stem cortex of the Carboniferous seed fern Lyginopteris oldhamia. Proceedings of the Royal Society B, 278: 675-680.
- Strullu-Derrien C, Rioult JP, Strullu DG (2009) Mycorrhizas in Upper Carboniferous Radiculites-type Cordaitalean rootlets. New Phytologist, 182: 561-564.
- Remy W, Taylor TN, Hass H, Kerp H (1994) Four hundred-million-year-old vesicular arbuscular mycorrhizae. Proceedings of the National Academy of Sciences of the United States of America, 91: 11841-11843.