Parahemiphlebia
cretacica Damselfly
Class
Insecta, Order Odonata, Suborder Zygoptera, Family Hemiphlebiidae
Geological
Time: Lower Cretaceous, Late Aptian-Cenomanian (108-92 million years
ago)
Size: Insect
fossil has 29 mm wingspan; Head-Body length 25 mm; Matrix: 90 mm by
80 mm
Fossil Site:
Crato Formation, Nova Olinda Member, Ceara, Brazil
Description:
The Araripe Basin of Brazil is home to a fantastic array of exquisitely-detailed
Early Cretaceous fossils, some of which have been preserved in
three dimensions. While the entire formation has until the last
decade or so been termed the Santana Formation, David Martill
has separated out the slightly older insect-bearing strata as
the Nova Olinda Member of the Crato Formation. Quarrying operations
for the purposes of obtaining paving stones exposes the remarkable
insect fauna in much the same way that quarrying for lithographic
limestone in Solnhofen has afforded a panoply of wonderfully-preserved
Jurassic fossils in Germany. In addition to the many orders of
insects, spiders, scorpions, decapod crustaceans, and many plants
have been found. Interestingly, to date no pterosaurs or terrestrial
vertebrates have been found, in stark contrast to the overlying
Santana Formation deposits. This specimen is a member of the
Odonata (dragonflies and damselflies). The Odonata are well-represented
in the fossil record, with some 700 species known. They have
their origin in the proto-Odonates from the Carboniferous. Meganeuropsis
from the Permian of North America, with a 75 cm wingspan, was
the largest insect on record. This specimen is a fine damselfly
of the family Hemiphlebiidae. A few exceptionally rare examples
have been found with the metallic green coloring preserved. Interestingly
while numerous fossil larval dragonflies have been found, no
fossil damselfly larvae are known, possibly indicative of the
fact that the larvae lived in a lacustrine habitat outside of
the Crato lagoon.
|
|