DOI: 10.5061/dryad.wwpzgmst4
title: A new biomechanical approach on cranial sutures function: The role of contact elements in linear and non-linear models

description: Understanding cranial sutures and how they relieve and dissipate stress is
 essential to assess their role in cranial biomechanics and to develop
 highly accurate predictive models. This involves examining how ontogeny
 affects cranial sutures, as well as their morphology and function, and how
 these changes through time may impact essential biomechanical loadings
 such as chewing or direct biting. In this work we study the cranial
 sutures of Crocodylus niloticus in detail using contact elements under
 finite element analysis. Contact elements permit the creation of a
 physical relationship between two bones that are in contact and even to
 configure these relationships, e.g. in terms of movement or flexibility.
 The definition of bone contacts may require linear and/or non-linear
 computational solutions to attain higher accuracy. Herein, skull geometry
 is tested to determine how they may be altered by different types of
 contacts under various conditions. As predicted, the absence of sutures or
 cranial kinesis leads to a reduction in stress distribution across the
 skull, whereas sutures and cranial kinesis help the skull relieve stress
 and prevent certain bones from sustaining high stress levels. The type of
 contact used in individual sutures has a significant effect on the models’
 outcome. Additionally, feeding behaviors significantly impact cranial
 biomechanics, reflecting the influence of other variables that may be
 applied to the models.  As highlighted by the results, in order
 to obtain accurate results when analyzing fossil taxa, the nature of the
 cranial sutures should be taken into account. Therefore, developing
 predictive models based on living taxa is invaluable because it
 facilitates the study of extinct taxa for which there is a lack of
 information on the fibrous joints due to poor (or non-) preservation in
 the fossil record.
description: # Supplementary Information
 [https://doi.org/10.5061/dryad.4tmpg4fk9](https://doi.org/10.5061/dryad.4tmpg4fk9) The dataset contains a table in excel format called Table S1 and a text document in word format called Appendix S1. Table S1 provides values derived from Weighted Arithmetic Mean (MWAM) methodology (See Marcé-Nogué et al. 2016 for details). Each value is obtained from each of the 37 cranial bones analyzed of a Crocodylus niloticus analyzed under the different biomechanical loadings (Twist, Bilateral, Lateral). Results are highlight in colour, from blue to red: blue means lower stress results in contrast to red colours as values are higher. Green and yellow are intermediate values. A colour scale appear at the right bottom of the excel file.  Reference: Marcé-Nogué, J., S. de Esteban-Trivigno, C. Escrig, L. Gil. 2016. Accounting for differences in element size and homogeneity when comparing Finite Element models: Armadillos as a case study. Palaeontol. Electron. 19, 1–22. https://doi.org/10.26879/609 Appendix S1 provides additional results from simulated models under Finite Element Analysis (FEA) for crocodile skull.