Ptenidium kishenehnicum(Coleoptera: Ptiliidae), a New Fossil Described from the Kishenehn Oil Shales, with a Checklist of Previously Known Fossil Ptiliids

First fossil jacobsoniid beetle (Coleoptera):Derolathrus groehnin. sp. from Eocene Baltic amber

“…The hind wings of D . groehni and other flight-capable Derolathrus with a reduced surface area and a fringe of setae are like those that have repeatedly evolved in other minute insects, including many beetles like ptiliid beetles that have a fossil history dating to the Cretaceous (e.g., Shockley and Greenwalt, 2013). Instead of flapping their wings, these “featherwinged” insects may be “rowing” their wings, which is an adaptation to flight at low Reynolds numbers (Walker, 2002).…”

Diptera of the middle Eocene Kishenehn Formation. I. Documentation of diversity at the family level

“…Several factors affect the preservation of dipteran diversity in the Kishenehn Formation. Very small insects are often well-preserved (Huber and Greenwalt, 2011;Shockley and Greenwalt, 2013). Culicidae, of which over 70 specimens have been collected from the Coal Creek Member, have not been recorded as described species from either the Florissant or the Okanagan.…”

“…Taphonomic processes have produced a unique entomofauna, with a strong size bias against large specimens; fossil insects 1 cm or longer in length are rare and, with the exception of isolated wings, invariably poorly preserved. On the other hand, very small insects (e.g., ptiliid beetles and mymarid wasps) that are rarely found as compression fossils in other Lagerstätten, are frequently preserved in the Kishenehn Formation's oil shales (Huber and Greenwalt, 2011;Shockley and Greenwalt, 2013;Greenwalt et al, 2015a). As a result, the Coal Creek Member entomofauna provides insights into insect diversity that are not available from other major North American Lagerstätten.…”

Fossil Ants (Hymenoptera: Formicidae) of the Middle Eocene Kishenehn Formation

“…The Coal Creek Member (estimated to be ca. 46 million years old) of the Kishenehn Formation located in northwestern Montana (Fig 1) has recently been the focus of several paleoentomological studies (Huber & Greenwalt, 2011;Greenwalt et al, 2015;Greenwalt et al 2013;Shockley & Greenwalt, 2013;Greenwalt & Rust, 2014) based on a large and growing collection of fossils at the National Museum of Natural History (Washington, DC). The paleoclimate of the Kishenehn Basin 46 million years ago was tropical, with a mean annual temperature as much as 15°C higher than the region's current temperatures (Wolfe, 1995;Zachos et al, 2001;Huber & Caballero, 2011), and characterized by low temperature seasonality, similar to extant tropical forests RESEARCH ARTICLE -ANTS 1 -Towson University, Towson, Maryland, USA 2 -National Museum of Natural History, Smithsonian Institution, Washington, D.C., USA (Archibald et al, 2010(Archibald et al, , 2013.…”