Giant sawfly from China: pterosaur & dinosaur nummies?

[Ben Creisler <bcreisler@gmail.com>]

From: Ben Creisler
bcreisler@gmail.com


A new non-dino paper that may be interest--some DML members are
interested in fossil insects.


Taiping Gao, Chungkun Shih, Alexandr P. Rasnitsyn &  Dong Ren (2013)
Hoplitolyda duolunica gen. et sp. nov. (Insecta, Hymenoptera,
Praesiricidae), the Hitherto Largest Sawfly from the Mesozoic of
China.
PLoS ONE 8(5): e62420.
doi:10.1371/journal.pone.0062420
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0062420

Background

Large body size of an insect, in general, enhances its capability of
predation, competition, and defense, resulting in better survivability
and reproduction. Hymenopterans, most being phytophagous or parasitic,
have a relatively small to medium body size, typically under 50.0 mm
in body length.

Principal Findings

Herein, we describe Hoplitolyda duolunica gen. et sp. nov., assigned
to Praesiricidae, from the Early Cretaceous Yixian Formation of China.
This new species is the largest fossil hymenopteran hitherto with body
estimated >55.0 mm long and wing span >92.0 mm. H. duolunica is, to
our knowledge, the only sawfly with Sc present in the hind wing but
not in the forewing. Its Rs1 and M1 meeting each other at 145° angle
represents an intermediate in the transition from “Y” to “T” shapes.
Even though Hoplitolyda differs significantly from all previously
described genera in two subfamilies of Praesricidae, we leave the new
genus unplaced in existing subfamilies, pending discovery of material
with more taxonomic structure.

Conclusions/Significance

Hoplitolyda has many unique and interesting characters which might
have benefitted its competition, survival, and reproduction: large
body size and head with robust and strong mandibles for defense and/or
sexual selection, unique wing venation and setal arrangements for
flight capability and mobility, dense hairs on body and legs for
sensing and protection, etc. Considering the reported ferocious
predators of feathered dinosaurs, pterosaurs, birds, and mammals
coexisting in the same eco-system, Hoplitolyda is an interesting case
of “survival of the fittest” in facing its evolutionary challenges.