A Cretaceous Chafer Beetle (Coleoptera: Scarabaeidae) with Exaggerated Hind Legs-Insight from Comparative Functional...

Area of Science:

• Paleontology
• Evolutionary Biology
• Insect Morphology

Background:

• Scarabaeidae beetles exhibit diverse exaggerated morphological structures, including horns and enlarged appendages.
• Mesozoic insects, particularly beetles, are key to understanding evolutionary pathways of complex traits.

Purpose of the Study:

• To describe and analyze a new species of Mesozoic scarab beetle, Antiqusolidus maculatus gen. et sp. n.
• To investigate the function of exaggerated hind leg structures in A. maculatus using biomechanical analyses.
• To determine the phylogenetic position of A. maculatus within the Scarabaeoidea superfamily.

Main Methods:

• Phylogenetic analysis using maximum parsimony based on morphological characters.
• Biomechanical simulations and finite element analysis to hypothesize leg function.
• Comparative morphological study of fossil specimens.

Main Results:

• Description of Antiqusolidus maculatus gen. et sp. n. from the Lower Cretaceous Yixian Formation.
• Hypothesized function of enlarged hind leg spurs and apical process for springing (movement and fighting).
• Phylogenetic placement of Antiqusolidus as sister to Rutelinae within pleurostict Scarabaeidae.
• Evidence suggests A. maculatus was diurnal with potential interactions with Early Cretaceous flora.

Conclusions:

• The study reveals novel insights into exaggerated morphological structures in Mesozoic insects.
• Antiqusolidus maculatus provides a unique example of functional morphology in extinct beetles.
• The findings contribute to understanding the evolution and paleoecology of Scarabaeoidea.