Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
PLoS One. 2012;7(6):e39323. doi: 10.1371/journal.pone.0039323. Epub 2012 Jun 22.
Taphonomic deformation can make the interpretation of vertebrate fossil morphology difficult. The effects of taphonomic deformation are investigated in two ankylosaurid dinosaur taxa, Euoplocephalus tutus (to investigate effects on our understanding of intraspecific variation) and Minotaurasaurus ramachandrani (to investigate the validity of this genus). The ratio of orbit maximum rostrocaudal length to perpendicular height is used as a strain ellipse, which can be used to determine if ankylosaur skull fossils have been dorsoventrally compacted during fossilization and diagenesis. The software program Geomagic is used to retrodeform three-dimensional (3D) digital models of the ankylosaur skulls. The effects of sediment compaction are modeled using finite element analysis, and the resulting strain distributions are compared with the retrodeformed models as a test of the retrodeformation method. Taphonomic deformation can account for a large amount of intraspecific variation in Euoplocephalus, but finite element analysis and retrodeformation of Minotaurasaurus shows that many of its diagnostic features are unlikely to result from deformation.
化石化变形会使脊椎动物化石形态的解释变得困难。本文研究了两种甲龙类恐龙（研究其对种内变异理解的影响）和 Minotaurasaurus 的化石化变形效应（研究这个属的有效性）。眼眶最大矢状长与垂直高的比值被用作应变椭圆，可以用来确定甲龙类头骨化石在化石形成和成岩过程中是否发生了背腹压缩。Geomagic 软件被用于反演甲龙头骨的三维数字模型。使用有限元分析来模拟沉积物压实的影响，并将得到的应变分布与反演模型进行比较，以此检验反演方法的有效性。化石化变形可以解释 Euoplocephalus 中大量的种内变异，但 Minotaurasaurus 的有限元分析和反演表明，其许多诊断特征不太可能是由变形引起的。
