DOI: 10.5061/dryad.nr210
title: Data from: The evolution of skull and body shape in Triturus newts reconstructed from 3D morphometric data and phylogeny

description: To explore the relationship between morphological change and species
 diversification, we reconstructed the evolutionary changes in skull size,
 skull shape, and body elongation in a monophyletic group of eight species
 that make up salamander genus Triturus. Their well-studied phylogenetic
 relationships and the marked difference in ecological preferences among
 five species groups makes this genus an excellent model system for the
 study of morphological evolution. The study involved three-dimensional
 imagery of the skull and the number of trunk vertebrae, in material that
 represents the morphological, spatial, and molecular diversity of the
 genus. Morphological change largely followed the pattern of descent. The
 reconstruction of ancestral skull shape indicated that morphological
 change was mostly confined to two episodes, corresponding to the ancestral
 lineage that all crested newts have in common and the Triturus dobrogicus
 lineage. When corrected for common descent, evolution of skull shape was
 correlated to change in skull size. Also, skull size and shape, as well as
 body shape, as inferred from the number of trunk vertebrae, were
 correlated, indicating a marked impact of species' ecological
 preferences on morphological evolution, accompanied by a series of niche
 shifts, with the most pronounced one in the T. dobrogicus lineage. The
 presence of phylogenetic signal and correlated evolutionary changes in
 skull and body shape suggested complex interplay of niche shifts, natural
 selection, and constraints by a common developmental system
description: Triturus and Calotriton
 landmark coordinatesThree-dimensional (3D)
 models of Triturus skulls were obtained from 177 specimens (121 cleared
 and stained skeletons from the Institute of Biological Research “Siniša
 Stanković“, Belgrade and 56 alcohol preserved at the Naturalis
 Biodiversity Center, Leiden). Specimens vaucher numbers are presented in
 the file. The specimens were scanned with a Skyscan 1172 100 kV computed
 microtomograph (micro CT-scanner; Skyscan, Aartselaar, Belgium) under
 settings that were optimized for the material (aluminium ﬁlter Al 0.5 mm,
 74 kV, 0.8 rotation step, 515 ms exposure time, four frame averaging). The
 3D surface models of newt skulls were produced using SkyScan CT Analyser®
 1.10 software, under a marching cube algorithm and a resolution of 26.1
 µm. Forty-eight landmarks were defined. A key to the landmarks, brief
 anatomical descriptions are presented in the file. The landmark
 coordinates were recorded from the surface models with the software
 Landmark IDAV 3.0. at http://graphics.idav.ucdavis.edu/research/EvoMorph).
 Dataset consisting of raw landmark coordinates is
 presented.Landmarks numbers and
 positioning48 landmarks (22
 bilaterally symmetric and four medial landmarks) and wireframe on the
 dorsal and lateral side of a Triturus skull.Lateral dorsal and
 ventral skull of specimen 2C30The image of the skull
 is derived from a CT scan with a spatial resolution of 26.1 µm. a)
 lateral, b) dorsal and d) ventral side of Triturus macedonicus (number
 2C30) is presentedvideo presentation of
 Triturus and Calotriton skullsVideo representation of
 Calotriton asper (ZMA.RenA.44640), Triturus carnifex (IBISS.5c35),
 Triturus cristatus (IBISS.20052), Triturus dobrogicus (IBISS.14C10),
 Triturus ivanbureschi (IBISS.22444), Triturus karelinii (IBISS 22242),
 Triturus macedonicus (IBISS.15c30), Triturus marmoratus
 (ZMA.RenA.7614_165) and Triturus pygmaeus (IBISS.22576) skulls. MP4 files
 for each species separately are zipped together.