At last, a Pennsylvanian stem-stonefly (Plecoptera) discovered

Area of Science:

• Paleontology
• Entomology
• Insect Phylogeny

Background:

• Pennsylvanian fossils reveal stem-relatives of many winged insect orders.
• Stoneflies (Plecoptera) were expected in Pennsylvanian fossils due to their basal phylogenetic position.
• No convincing stonefly relatives had been identified from this period previously.

Purpose of the Study:

• To identify and describe new fossil insect species from the Pennsylvanian period.
• To determine the phylogenetic placement of newly discovered fossil insects.
• To reassess the diversity and evolutionary history of early winged insects.

Main Methods:

• Analysis of wing venation in fossil specimens from the Tupo Formation, China.
• Comparative morphological analysis of fossil species with extant stonefly species.
• Phylogenetic analysis to ascertain the order-level and species-level identification of fossils.

Main Results:

• Discovery and description of Gulou carpenteri gen. et sp. nov., a new fossil insect species.
• Wing venation of G. carpenteri exhibits Plecoptera diagnostic states, but lacks some unequivocal characteristics.
• Identification of a rare, atavistic trait in G. carpenteri, and reconsideration of putative stem-stonefly taxa.

Conclusions:

• Gulou carpenteri gen. et sp. nov. is identified as the sole genuine Plecoptera from the Pennsylvanian period.
• The study indicates a more diverse Pennsylvanian insect fauna than previously understood.
• Fossil evidence suggests a longer, undocumented evolutionary history for insects prior to the Pennsylvanian.