Friday, April 23, 2021

[PaleoEntomology • 2021] Pelretes vivificus • Angiosperm Pollinivory in A Cretaceous Beetle


Ecological reconstruction of Pelretes vivificus vesting angiosperm flowers in the Burmese amber forest (~99 Ma).  
Tihelka, Li, Fu, Su, Huang & Cai, 2021

Artwork by Jie Sun

Abstract
Despite the crucial importance of flower-visiting insects in modern ecosystems, there is little fossil evidence on the origins of angiosperm pollination. Most reports of pollination in the Mesozoic fossil record have been based on the co-occurrence of the purported pollinators with pollen grains and assumed morphological adaptations for vectoring pollen. Here, we describe an exceptionally preserved short-winged flower beetle (Cucujoidea: Kateretidae) from mid-Cretaceous amber, Pelretes vivificus gen. et sp. nov., associated with pollen aggregations and coprolites consisting mainly of pollen, providing direct evidence of pollen-feeding in a Cretaceous beetle and confirming that diverse beetle lineages visited early angiosperms in the Cretaceous. The exquisite preservation of our fossil permits the identification of the pollen grains as Tricolpopollenites (Asteridae or Rosidae), representing a record of flower beetle pollination of a group of derived angiosperms in the Mesozoic and suggesting that potentially diverse beetle lineages visited early angiosperms by the mid-Cretaceous.


Dorsal view of Pelretes vivificus, a Cretaceous short-winged flower beetle (Kateretidae) from Burmese amber (~99 Ma). Scale bar: 200 μm.  

Aggregations of eudicot pollen and pollen-containing coprolites associated with Pelretes vivificus.
a, Amber piece with P. vivificus, showing coprolites and one pollen aggregation. b-e, details of pollen under visible light (d) and confocal laser scanning microscopy (b, c, e).
 Scale bars: 1 mm (a), 50 μm in (b, e), 100 μm (c, d).  

 Pelretes vivificus gen. et sp. nov.


Ecological reconstruction of Pelretes vivificus vesting angiosperm flowers in the Burmese amber forest (~99 Ma). 
 Artwork by Mr. Jie Sun

  
Erik Tihelka, Liqin Li, Yanzhe Fu, Yitong Su, Diying Huang and Chenyang Cai. 2021. Angiosperm Pollinivory in A Cretaceous Beetle. Nature Plants. DOI: 10.1038/s41477-021-00893-2 

Unusual fossil reveals last meal of prehistoric pollinator