Illusion of flight? Absence, evidence and the age of winged insects.

This article focuses on evaluating the discrepancy between the fossil record and molecular phylogenetic estimates regarding the origin of winged insects (Pterygota). While the earliest definitive pterygote fossils date to the mid-Carboniferous (~328–324 million years ago), molecular studies often suggest an origin during the Silurian or Devonian (~440–370 million years ago), implying a substantial ~50–100 million-year gap in the fossil record. Through multiple analyses—including comparative fossil occurrence bootstrapping, Bayesian age estimation with PyRate, re-analyses of molecular divergence times using different fossil calibration datasets, and simulations of fossil record completeness—the study finds little support for explanations such as sampling bias, preservation bias, or small body size to account for this gap. Instead, the authors suggest that the older molecular age estimates likely result from analytical artifacts related to fossil calibration choices, taxon sampling, and rate heterogeneity in molecular evolution, concluding that crown-group Pterygota most plausibly originated in the Late Mississippian (Late Carboniferous), closely aligning with their first fossil appearances.