Significance of the suture line in cephalopod taxonomy revealed by 3D morphometrics in the modern nautilids Nautilus and Allonautilus

A Tajika, N Morimoto, NH Landman - Scientific Reports, 2021 - nature.com
A Tajika, N Morimoto, NH Landman
Scientific Reports, 2021nature.com
Assessing the taxonomic importance of the suture line in shelled cephalopods is a key to
better understanding the diversity of this group in Earth history. Because fossils are subject
to taphonomic artifacts, an in-depth knowledge of well-preserved modern organisms is
needed as an important reference. Here, we examine the suture line morphology of all
known species of the modern cephalopods Nautilus and Allonautilus. We applied computed
tomography and geometric morphometrics to quantify the suture line morphology as well as …
Abstract
Assessing the taxonomic importance of the suture line in shelled cephalopods is a key to better understanding the diversity of this group in Earth history. Because fossils are subject to taphonomic artifacts, an in-depth knowledge of well-preserved modern organisms is needed as an important reference. Here, we examine the suture line morphology of all known species of the modern cephalopods Nautilus and Allonautilus. We applied computed tomography and geometric morphometrics to quantify the suture line morphology as well as the conch geometry and septal spacing. Results reveal that the suture line and conch geometry are useful in distinguishing species, while septal spacing is less useful. We also constructed cluster trees to illustrate the similarity among species. The tree based on conch geometry in middle ontogeny is nearly congruent with those previously reconstructed based on molecular data. In addition, different geographical populations of the same species of Nautilus separate out in this tree. This suggests that genetically distinct (i.e., geographically isolated) populations of Nautilus can also be distinguished using conch geometry. Our results are applicable to closely related fossil cephalopods (nautilids), but may not apply to more distantly related forms (ammonoids).
nature.com
以上显示的是最相近的搜索结果。 查看全部搜索结果