Figure 2.

Bayesian maximum clade credibility chronogram with MOTU designation for G. fossarum. The outgroup is removed for clarity. Each BIN is represented by one randomly chosen haplotype. Grey bars at key nodes represent 95%HPD (Highest Posterior Density) intervals of clade age. Circles at nodes represent Posterior Probabilities (PP) for Bayesian Inference (BI) and as bootstrap values (BS) for Maximum Likelihood (ML, see Fig. S1), according to the following colour code: black: PP ≥ 95%/BS ≥ 55%, grey: PP = 95–80%/BS = 54–30% and white: PP < 79%/BS < 30%, unlabeled = bipartition not recovered in both analyses. Precise values are given for key nodes. Bars annotated on the right represent results of the MOTU delimitation methods i.e. Barcode Index Number (BIN), the Bayesian implementation of the Poisson Tree Processes (bPTP), the Automatic Barcode Gap Discovery (ABGD) and Lagrue's reproductive isolation methods, respectively. Three ABGD-MOTUs, 1, 2 and 6, corresponding to types A, B and C as defined by Müller et al. (2000), respectively are specified. Six major clades were distinguished and highlighted by the following colours: SEE (South-Eastern Europe, purple), FRA-CE A (France and Central-European A, yellow), EE Q (Eastern-Europe Q, dark blue), CWE (Central-Western Europe), CE A (Central-EuropeanA, yellow) and CEE (Central-Eastern Europe). First inset: Image of a male G. fossarum sensu stricto, i.e. Type A which occurs at the type locality (Photograph: Denis Copilaş-Ciocianu). Second inset: Lineages through time (LTT) plot. Analysis was performed on the dataset reduced to BINs. Grey lines represent 95%HPD. Tree was generated using BEAST 2.4.8 (https://www.beast2.org/).