Data from: Relaxed phylogenetics and the Palaeoptera problem: resolving deep ancestral splits in the insect phylogeny

The order in which the three groups of winged insects diverged from their
common ancestor has important implications for understanding the origin of
insect flight. But despite this importance, the split between the Odonata
(dragonflies and damselflies), Ephemeroptera (mayflies) and Neoptera (the
other winged orders) remains very much unresolved. Indeed, previous
studies have obtained strong apparent support for each of the three
possible branching patterns. Here, we present a systematic reinvestigation
of the basal pterygote split. Our results suggest that outgroup choice and
limited taxon sampling have been major sources of systematic error, even
for datasets with a large number of characters (e.g., in phylogenomic
datasets). In particular, a dataset of 113 taxa provides consistent
support for the Palaeoptera hypothesis (the grouping of Odonata with
Ephemeroptera), while results from datasets with fewer taxa give
inconsistent results, and are highly sensitive to minor changes in data
and methods. We also focus on recent methods that exploit temporal
information, combined with additional assumptions about the evolutionary
process, and so reduce the influence of outgroup choice. These methods are
shown to provide more consistent results, for example, supporting
Palaeoptera, even for datasets that previously supported other hypotheses.
Together, these results have implications for understanding insect origins
and for resolving other problematic splits in the tree of life.