Saturday 6 October 2018

Gollandia planata: A new species of Rove Beetle from Cretaceous Burmese Amber.

Rove Beetles, Staphylinidae, are the largest extant Beetle group, with around 63 000 known species, and have been around since at least the Triassic. They are easily distinguished from other Beetles by their much reduced elytra (wing cases) that leave most of the abdomen exposed. Rove Beetles are found in all habitats where Beetles are found, and are a highly diverse group, both ecologically, and morphologically, though most species are elongated, between two and eight mm in length and predators on smaller Arthropods.

In a paper published in the journal ZooKeys on 17 August 2018, György Makranczy of the Department of Zoology at the Hungarian Natural History Museum, Shûhei Yamamoto of the Integrative Research Center at the Field Museum of Natural History, and Michael Engel of the Division of Entomology, Natural History Museum and Department of Ecology & Evolutionary Biology at the University of Kansas, and the Division of Invertebrate Zoology at the American Museum of Natural History, describe a new species of Rove Beetle from a piece of Cretaceous Burmese Amber.

Cretaceous ‘Burmese Amber’ has been extensively worked at several sites across northern Myanmar (though mostly in Kachin State) in the last 20 years. The amber is fairly clear, and often found in large chunks, providing an exceptional window into the Middle Cretaceous Insect fauna. This amber is thought to have started out as the resin of a Coniferous Tree, possibly a Cypress or an Araucaria, growing in a moist tropical forest. This amber has been dated to between 105 and 95 million years old, based upon pollen inclusions, and to about 98.8 million years by uranium/lead dating of ash inclusions in the amber. 

The new species is named Gollandia planata, where 'Gollandia' honours Susan Golland, exhibition developer at the Field Museum of Natural History, and 'planata' derives from the Greek πλατύς (platys), meaning 'wide' in reference to the pronotum (plate covering the back of the thorax), which is exceptionally wide.

Gollandia planata photographed with macro lens and three flash units. (3) Dorsal
view. (4) Ventral view. Makranczy et al. (2018).

The species is described from a single specimen from a piece of amber from Noije Bum Hill in the southwest Hukawng Valley of Kachin State, Myanmar. The specimen is well preserved, but caught within a dip in an internal layer in the amber (the amber is made up of successive layers of resin that have flowed over one-another), and was initially prepared (probably by local workers in the area) in such a way that this cannot now be rectified by polishing away the problematic layers.

The specimen is probably male, and is 3.29 mm in length, reddish brown in colour, with a dense coat of hairs on its abdomen and less on the forepart of the body. It has hindwings extended over the body and well preserved.

See also...
Follow Sciency Thoughts on Facebook.