Divergence time estimation
Divergence time was estimated using the uncorrelated relaxed clock model
as implemented in BEAST v. 1.6.1 (Drummond and Rambaut, 2007). In order
to limit the numbers of parameter for the estimation, Bayesian tree was
used as a guide tree. The tree prior
generated using a Yule speciation model, and all node calibrations were
enforced using Normal distributions. Constraints on clade ages were
enforced using three fossil calibrations. Mordellidae
(Protoripidius burmiticus ) diverged from the other lineages in
the Tenebrionoidea approximately in 166.6 Mya (Cai et al ., 2018),
Anthicidae-Meloidae (Camelomorpha longicervix ) split at 145 Mya
(Kirejtshuk et al ., 2008), and Tenebrionidae-Lagriidae
(Alphitopsis initialis ) split at 143.6 Mya (Kirejtshuk et
al ., 2012). The posterior time estimation was conducted using a MCMC
algorithm, and the MCMC run was sampled every 1 000 iterations until it
achieved 10 000 samples, after the first 100 000 iterations were
discarded as burn-in. The effective sample sizes of every node age were
confirmed using Tracer v. 1.5 until
every parameter being >200. The maximum clade credibility
tree was calculated using TreeAnnotator v. 1.6.1, with the node times
scaled to match the mean posterior estimates.