Wednesday 21 November 2012

Miocene Quasimodo Flies in Dominican Amber.

Quasimodo Flies (Curtonotidae) are small Flies with dull colouration and distinctively humped backs. They are distributed throughout the world, though in most places they are quite uncommon. However in Africa and tropical America they are an abundant and diverse part of the insect fauna. The group have not been extensively studied, and therefore are not well understood.

In a paper published in the American Museum Novitates on 18 October 2012, David Grimaldi Division of Invertebrate Zoology at the American Museum of Natural History and Ashley Kirk-Spriggs of the National Museum in Bloomfontein and the School of Life Sciences at the University of KwaZulu-Natal describe two new species of Quasimodofly from Miocene amber from the Dominican Republic, thought to be 15-20 million years old. Only one fossil Quasimodofly has previously been described (Curtonotum gigas from French Oligocene shale in 1937), and this is now thought to have been erroneously placed, making these new specimens both the oldest and the only known fossils of the group.

The first new species is placed in the pre-existing genus Curtonotum (an extant genus of Quasimodo Flies to which Curtonotum gigas was assigned; the species was removed from the genus and family in 2007 in a paper by Ashley Kirk-Spriggs, but has never been reassigned to another taxon), and given the specific name electrodominicum, meaning from Dominican amber (ēlectron, Greek for amber, plus dominicum, from Dominica). Curtonotum electrodominicum is 7 mm Fly, not significantly humpbacked, named from a single specimen in amber. 

Curtonotum electrodominicum, specimen in amber. Grimaldi & Kirk-Spriggs (2012).

The second new species is placed in a new genus, Depressonotum, meaning flattened, and given the specific name priscum, meaning ancient. The species is named from two specimens, one male and one female, with an average length of 2.77 mm, large eyes and a flattened abdomen. The male is notably more slender than the female.

Depressonotum priscum; (top) female, (bottom) male. Grimaldi & Kirk-Spriggs (2012).

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