Late Carboniferous paleoichnology reveals the oldest full-body impression of a flying insect

Abstract

Insects were the first animals to evolve powered flight and did so perhaps 90 million years before the first flight among vertebrates. However, the earliest fossil record of flying insect lineages (Pterygota) is poor, with scant indirect evidence from the Devonian and a nearly complete dearth of material from the Early Carboniferous. By the Late Carboniferous a diversity of flying lineages is known, mostly from isolated wings but without true insights into the paleoethology of these taxa. Here, we report evidence of a fullbody impression of a flying insect from the Late Carboniferous Wamsutta Formation of Massachusetts, representing the oldest trace fossil of Pterygota. Through ethological and morphological analysis, the trace fossil provides evidence that its maker was a flying insect and probably was representative of a stem-group lineage of mayflies. The nature of this current full-body impression somewhat blurs distinctions between the systematics of traces and trace makers, thus adding to the debate surrounding ichnotaxonomy for traces with well-associated trace makers.Ephemeroptera | ethology | ichnology | Pennsylvanian

A stressful shortness of breath: molting disrupts breathing in the mayfly Cloeon dipterum

“…Molting temperature was taken as the temperature at the lowest measurement of the deficit phase. earth (Knecht et al 2011), and can molt up to 52 times as larvae (Gros 1925), whereas 4 to 5 larval molts are typical in more contemporary lineages (Benke and Wallace 1980). Whether molting number or frequency play a role in determining the susceptibility of species to thermal change or other environmental stressors is unclear.…”

Reanalysis and Experimental Evidence Indicate That the Earliest Trace Fossil of a Winged Insect Was a Surface-Skimming Neopteran

“…This reinterpretation is based on published images and text in the original report (Knecht et al 2011), and a high‐resolution unpublished photograph of the fossil. No features of the fossil were considered beyond what was presented in the original report.…”

“…Winged insects (Pterygota) diverged and radiated during the Carboniferous (360–300 mya), yet insect fossils from that period are sparse and consist primarily of wings or wing fragments (Grimaldi and Engel 2005). A remarkably detailed full‐body imprint fossil of a pterygote insect was recently discovered from the Late Carboniferous (Knecht et al 2011) and provides rare information about morphology, habitat, and behavior, but correct interpretation of the imprint features and its maker's taxonomic identity are critical. Knecht et al concluded that the imprint was most likely produced by a lineage that gave rise to mayflies (Ephemeropterida).…”

“…None of this critique challenges the geological analysis or interpretation of the habitat. A full description of the fossil and its setting is contained in the original publication (Knecht et al 2011).…”

An orchid bee of the genus <i>Eulaema</i> in Early Miocene Mexican amber (Hymenoptera: Apidae)

“…It would not be unexpected for stem-group Euglossini to potentially reside outside of the area of distribution of modern orchid bees, perhaps even far afield as has been discovered in the pattern of biogeography for other corbiculate tribes (e.g., Kotthoff et al, 2013). In addition, euglossine fossils have the potential to preserve direct or indirect evidence of paleobiologies and behaviors, illuminating the early evolution of complex behavioral suites (e.g., Engel, 2009c;Chaboo et al, 2009;Wedmann et al, 2009;Davis & Engel, 2010;Wang et al, 2010;Batelka et al, 2011;Knecht et al, 2011;Gu et al, 2012;Pérez-de la Fuente et al, 2012;Huang et al, 2012Huang et al, , 2013Krogmann et al, 2013;Wappler et al, 2013). Evolving techniques of study and a greater appreciation of fossils will ultimately provide broader avenues for unraveling the origins of the charismatic Euglossini and their intimate relationship with orchids.…”