Jurassic scorpionflies (Mecoptera) with swollen first metatarsal segments suggesting sexual dimorphism.

ABSTRACT:

Background

Sexual dimorphism is widespread in insects. The certain specialized structures may be used as weapons in male-male combats or as ornaments to enhance mating opportunities.

Results

We report striking swollen first tarsal segments in two families, four genera and six species of scorpionflies from the Middle Jurassic Yanliao Biota of Northeastern China. Swollen tarsal segments are restricted to male specimens and to hind leg tarsi. The geometric morphometric analyses reveal that the degree of swelling within the orthophlebiid species possessing swollen first metatarsal segments is species-specific, which can be used as a diagnostic character for taxonomic and phylogenetic studies.

Conclusions

The new findings indicate that swollen first metatarsal segments are

SUBMITTER: Zhang YJ 

PROVIDER: S-EPMC7981964 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature