An exceptionally preserved 110 million years old praying mantis provides new insights into the predatory behaviour of early mantodeans

Marie K Hörnig,Joachim T Haug,Carolin Haug

doi:10.7717/peerj.3605

Marie K Hörnig, Joachim T Haug + Show 1 more

Open Access

https://doi.org/10.7717/peerj.3605

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Abstract

Mantodeans or praying mantises are flying insects and well known for their raptorial behaviour, mainly performed by their first pair of thoracic appendages. We describe here a new, exceptionally preserved specimen of the early mantodean Santanmantis axelrodi Grimaldi, 2003 from the famous 110 million years old Crato Formation, Brazil. The incomplete specimen preserves important morphological details, which were not known in this specific form before for this species or any other representative of Mantodea. Unlike in modern representatives or other fossil forms of Mantodea not only the first pair of thoracic appendages shows adaptations for predation. The femora of the second pair of thoracic appendages bear numerous strong, erect spines which appear to have a sharp tip, with this strongly resembling the spines of the first pair of thoracic appendages. This indicates that individuals of S. axelrodi likely used at least two pairs of thoracic appendages to catch prey. This demonstrates that the prey-catching behaviour was more diverse in early forms of praying mantises than anticipated.

Highlights

Praying mantises, or mantodeans, are iconic ‘‘flying insects’’ (Pterygota)
The specimen is identified as a representative of Santanmantis axelrodi based on its overall morphology
The specimen differs from other specimens interpreted as S. axelrodi in the clear presence of massive prominent spines on the femora and tibiae of the second pair of thoracic appendages

Summary

INTRODUCTION

Mantodeans, are iconic ‘‘flying insects’’ (Pterygota). They are especially famous for their evolutionary adaptations to predatory behaviour (Svenson & Whiting, 2004). Despite the overall cockroach-like habitus, the first pair of thoracopods strongly resembles that of mantodeans concerning shape of the femur, relative length of the tibia, and armature with spines on both leg elements These similarities were interpreted as synapomorphies of R. waddingtonae and Mantodea by Dittmann et al (2015). The tibiae of the first pair of thoracic appendages of R. waddingtonae only differ from those of mantodeans by lacking a prominent, curved distal spine, which most likely represents an (aut-)apomorphy of Mantodea. Given this morphology, R. waddingtonae gives an important signal for the order of character acquisition along the evolutionary lineage towards Mantodea. We discuss a new interpretation of the raptorial behaviour of S. axelrodi and early mantodeans in general

MATERIAL AND METHODS

DISCUSSION