Generalist Pollen-Feeding Beetles during the Mid-Cretaceous

Area of Science:

• Paleontology
• Evolutionary Biology
• Botany

Background:

• The Cretaceous fossil record, particularly amber, offers insights into early pollination.
• Understanding insect-pollinator relationships is key to deciphering plant evolution.

Purpose of the Study:

• To investigate early pollination strategies during the mid-Cretaceous.
• To analyze insect-plant interactions using fossil evidence from Myanmar amber.

Main Methods:

• Examination of four amber specimens from Kachin, Myanmar, dated to approximately 99 million years old (early Cenomanian).
• Identification of four closely related genera of short-winged flower beetles (Coleoptera: Kateretidae).
• Analysis of associated pollen grains, including gymnosperm pollen (Cycadopites) and a basal angiosperm pollen taxon (Praenymphaeapollenites cenomaniensis).

Main Results:

• Discovery of Kateretidae beetles associated with both gymnosperm and early angiosperm pollen.
• Identification of Praenymphaeapollenites cenomaniensis, a pollen type from a basal water lily lineage (Nymphaeaceae).
• Evidence of a gymnosperm to angiosperm plant-host shift in these beetles during the mid-Cretaceous.

Conclusions:

• The observed beetle-pollen associations demonstrate a significant shift in plant-host utilization.
• This host shift by generalist pollen-feeding beetles likely played a role in the evolutionary success of angiosperms.
• Fossil amber provides critical evidence for reconstructing ancient pollination networks and plant evolution.