3D geometric morphometrics of thorax variation and allometry in Hominoidea

Three‐dimensional analysis of sexual dimorphism in ribcage kinematics of modern humans

“…Ribcages were segmented through a semiautomatic protocol for DICOM images using Mimics 8.0 software program (http://biomedical.materialise.com/mimics) and subsequently reconstructed as 3D models. These 3D models were imported into Viewbox 4.0 software (http://www.dhal.com) for (semi‐) landmarking using the protocol from Bastir et al () for ribs 1–11. The protocol was updated to include the 12th thoracic level.…”

3D virtual reconstruction of the Kebara 2 Neandertal thorax

“…The traditional morphometric analysis consisted of: (a) the direct comparison of the morphology of the thorax between our reconstruction and modern humans and (b) the comparison of selected measurements between the K2 reconstruction and the modern human comparison sample (Table 1 ). For the GMM analysis we digitized 526 3D landmarks and semilandmarks on each ribcage using Viewbox 4 software ( www.dhal.com ), based on a recently published protocol for quantifying the ribcage of hominoids 68 . Additionally, a metric analysis of selected linear measurements of T1–T10 vertebrae was performed using a different comparative sample (Supplementary Note 1 ).…”

“…To assess the size and shape of the thorax using GMM, for ribs 1–10, 20 landmarks (7 fixed and 13 sliding); in ribs 11–12, 19 landmarks (6 fixed and 13 sliding) were captured in each rib, and four fixed landmarks at each thoracic vertebra 68 . For ribs 1–10, fixed landmarks at the rib head were digitized at the most superior and most inferior points with another landmark at the most medial point of the rib head at the inter-articular crest.…”

Eco‐geographic adaptations in the human ribcage throughout a 3D geometric morphometric approach

“…Even though this study considerably impacts our understanding of thorax adaptation to cold‐environments, some limitations must be noticed: (1) Asian individuals are not represented in our sample and future studies should cover also this large geographical region in order to confirm the hypotheses presented here; (2) Analyzing rib morphology is difficult in terms of amassing statistically significant sample sizes as every individual is made up of 12 ribs, especially when the number of individuals with complete ribs available for analysis are limited. While we analyze a fair amount of data, more effort must be paid in the future in order to expand sample sizes; (3) we only included fairly complete individuals in our sample in order to avoid uncertain caused because of missing data estimation but future studies could increase the sample using less complete individuals using different protocols for missing data estimation; (4) here we address thorax morphology based on the rib evidence but the thorax is actually an anatomical composite in which the thoracic vertebrae should be also considered in order to describe 3D detailed thorax morphology, which should be addressed in future studies (Bastir et al, ; García‐Martínez, ; García‐Martínez et al, ).…”

“…Although the tubercle‐ventral arch, along with the tubercle‐ventral cord, is useful for quantifying differences in rib curvature in the cranial view (Gómez‐Olivencia et al, ), several attempts using angles have been used to try to quantify other important features, such as rib torsion (Jellema, Latimer, & Walker, ), but this feature is not well quantified using traditional measurements. This is because rib torsion modifies the curvature not only in the transverse plane but also in the saggital and the coronal planes (García‐Martínez et al, ), therefore necessitating for the use of 3D geometric morphometrics in order to quantify the 3D rib morphological variability (Bastir et al, ; Chapman et al, ; García‐Martínez et al, ; García‐Martínez, Torres‐Tamayo, Torres‐Sanchez, García‐Río, & Bastir, ; Shi et al, ; Weaver, Schoell, & Stitzel, ). Finally, Gómez‐Olivencia et al () did not account for latitude, which has been related to temperature.…”