Figure legends
Figure 1: The Iberian Peninsula with records of Triturus
marmoratus (solid round symbols) and T. pygmaeus (open round
symbols). A – Localities sampled for the evaluation of SNP-marker
diagnosticity. For details see Supplementary Information S1. The boxed
area includes the Lisbon Peninsula and the Caldas da Rainha area. B –
Localities sampled in the Lisbon Peninsula, with symbols as above. For
details see Supplementary Information S2. The continuous distribution
with T. marmoratus in dark grey and T. pygmaeus in light
grey is from Arntzen et al. (2009) and Arntzen (2018). Note the
existence of a T. marmoratus enclave around Caldas da Rainha.
Localities codes are C for Caldas da Rainha, L for Lisbon and S for the
Serra de Sintra.
Figure 2: Two-species distribution models for the newtsTriturus marmoratus and T. pygmaeus over the Iberian
Peninsula, derived from the climatic variable ‘precipitation of driest
quarter’. A – present day. The colour legend shows the inferred
probability for the presence of T. marmoratus (blue) and T.
pygmaeus (Pm=0, red). Intermediate colours represent
intermediate probabilities. The light shaded area falls outside theTriturus range (see Figure 1). B – distribution models over the
western part of the Iberian Peninsula for the climate conditions of the
Mid Holocene. Inferred species ranges are shown in grey
(Pm>0.5) and in white
(Pm<0.5). Model representation is binary and
cumulative, so that the stepped grey scale represents the number of
models supporting the presence of T. marmoratus , from zero to
nine. C – as in B, for three climate reconstructions at the Last
Glacial Maximum. Note that most models support the contiguous species
border to be more or less stable, whereas one model supports a more
southern species border during the Late Glacial Maximum.