Data collection (3D acquisition)
We virtually reconstructed 101 crania of adult individuals ofDasyurus hallucatus – including males and females from four
mainland populations (Pilbara, Kimberley, Northern Territory and
Queensland) and other island populations (Groote Eylandt and other small
islands). Adult status was determined through incisor wear
(Oakwood, 2000) and P3 eruption (Woolley et al., 2013). We 3D-scanned
most of the specimens from museum collections (Queensland Museum,
Australian Museum, Western Australian Museum, Australian National
Wildlife Collection and American Museum of Natural History) with a
GoMeasure 3D HDI109 blue light surface scanner (LMI Technologies Inc.,
Vancouver, Canada). Each cranium was placed in 3 different orientations
on a motored rotary table that turned every 45 degrees (8 rotations per
round). The 24 resulting 3D images (8 rotations x 3 orientations) were
then meshed together with the scanner’s software (FlexScan3D
3.3) to export a complete 3D image of each skull. This file was then
treated in for hole filling (so as to not affect the biological shape of
the structure), mesh decimation (to facilitate computation) and mesh
reformatting (as “.ply” files need to be in binary format for
subsequent importations of the mesh in R). Several photos of each
specimen were also taken to help identify landmarks by discriminating
biological structures from 3D artefacts in the landmarking process.
Seven fully fleshed specimens from the Groote Eylandt population were
CT-scanned at the Centre for Advanced Imaging at The University of
Queensland in a micro CT-scanner. In order to obtain the 3D model,
segmentation of the DICOM grayscale images provided by the micro CT-scan
was performed with Mimics Research version 20.0. All 3D models
can be accessed through MorphoSource. The University of Queensland
animal ethics committee (permit number SBS/009/16/ARC) and the Northern
Territory Parks and Wildlife Commission (permit number 58566) approved
the research methods and the collection of the Groote Eylandt specimens.