A mid-Cretaceous Eccrinales infesting a primitive wasp in Myanmar amber.

Area of Science:

• Paleomycology
• Insect Paleontology
• Cretaceous Ecosystems

Background:

• The order Eccrinales comprises fungi with a unique parasitic lifestyle.
• Fossil records of Eccrinales are scarce, limiting understanding of their evolutionary history.
• Insect-fungus interactions in the Cretaceous are crucial for understanding co-evolution.

Purpose of the Study:

• To describe a new genus and species of Eccrinales from mid-Cretaceous Myanmar amber.
• To investigate the host-parasite relationship between this fossil fungus and its insect host.
• To establish the presence of Eccrinales in the mid-Cretaceous and infer early host associations.

Main Methods:

• Microscopic examination of fossilized fungal structures within amber.
• Morphological analysis of sporangiospores and thalli.
• Comparative analysis with extant Eccrinales and other fossil fungi.

Main Results:

• Description of Paleocadus burmiticus gen. et sp. nov. from the family Eccrinaceae.
• Identification of two distinct sporangiospore types, indicating different reproductive or dispersal strategies.
• Fossil fungus found associated with the anus of a primitive wasp, suggesting a parasitic relationship.

Conclusions:

• The discovery of Paleocadus burmiticus confirms the presence of Eccrinales in the mid-Cretaceous.
• This fossil provides the first evidence of Eccrinales parasitizing wasps during this period.
• The observed association highlights a previously unknown ancient insect-fungal interaction, distinct from modern Eccrinales.