Fluctuation in the diversity of mayflies (Insecta, Ephemerida) as documented in the fossil record

Abstract

Due to their aquatic larvae, the evolution of mayflies is intricately tied to environmental changes affecting lakes and rivers. Despite a rich fossil record, little is known about the factors shaping the pattern of diversification of mayflies in deep time. We assemble an unprecedented dataset encompassing all fossil occurrences of mayflies and perform a Bayesian analysis to identify periods of increased origination or extinction. We provide strong evidence for a major extinction of mayflies in the mid-Cretaceous. This extinction and subsequent faunal turnover were probably connected with the rise of angiosperms. Their dominance caused increased nutrient input and changed the chemistry of the freshwater environments, a trend detrimental mainly to lacustrine insects. Mayflies underwent a habitat shift from hypotrophic lakes to running waters, where most of their diversity has been concentrated from the Late Cretaceous to the present.

Comparative Mitogenome of Phylogenetic Relationships and Divergence Time Analysis within Potamanthidae (Insecta: Ephemeroptera)

“…In addition, Lord discovered the presence of algae in the stomach contents of larvae during dissection, indicating that this taxon fed on algae, consistent with the appearance of calcium algae and diatoms in the Mesozoic Era that could also provide an optimal environment for the origin of the Potamanthidae [114,115]. The known fossils of Potamanthidae were speculated to have originated in the Cretaceous period, and the formation of these fossils was within the time interval for the inferred origin of Potamanthidae, as determined by this study [30,31,38,116]. In addition, Siphluriscidae diverged at 193.96 Mya (95% HPD, 169.80-226.13 Mya) in the Mesozoic Jurassic period.…”

“…Back in the early 19th century, researchers began to concentrate on the fossils of Ephemeroptera, and significant progress had been made in the study of these fossils, with research now encompassing not only morphological descriptions but also aspects such as geographical distribution and systematics. Information on a few Potamanthidae fossils is available online (www.fossilworks.org), being focused on Olindinella gracilis, which has already gone extinct [38], and Nanophemera myanmarensis, and Crepotamanthus spinitarsus, which are possibly closely related to Potamanthidae and have also gone extinct [30,31]. Based on 1478 single-copy genes, Misof et al proposed that about 239 Mya, mayfly began to diversify [39].…”