Cretaceous Ephemeroptera Nymph Fossil

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 fine example shows a mayfly naiad (nymph) in ventral view. The Ephemroptera arose during the Permian. The name refers to the ephemeral existence of adults who live for a few hours to a few days post-emergence. Note the preserved limbs and feathery gills; preserved as well are the tripartite terminal filaments which had a role in propulsion.