Origins Conference 2022 part 2: Doran and McLain´s Ankylosauria analysis
Biology abstracts
Geology Abstracts
The annual Origins conference is one of the foremost creationist conferences involving multiple disciplines, primarily: biology, geology, and theology. In this series of posts, I will review the published works this year that I can comment on, unfortunately, I cannot comment on most of what occurred since it is simply outside of my field and I don´t understand it.
N.A. Doran and M.A. McLain 2022 “The Ankylosauria: A Bottom-Heavy Holobaramin?”
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| Euoplocephalus tutus, an Ankylodaurid from North America. Drawing by Scott Hartman (C) 2018. |
Unlike my previous review of McLain´s (2022) analysis on pterosaurs, I can comment on Ankylosaurs. Ankylosaurs are some of the most iconic dinosaurs the world has ever seen, the group´s namesake Ankylosaurus has appeared in the Jurassic World franchise frequently and several other movies and tv shows. The group is divided into two parts, Ankylosauridae and Nodosauridae.
Doran and McLain analyzed a character set from Zheng et al. 2018 which described a new species of ankylosaurine from China and its implications for the evolution of the Ankylosaurid tail club. We´ll discuss the club in a moment.
The analysis was aimed at using disparity calculations to evaluate medoid partitioning results.
Two sets of analyses were conducted on the dataset one at a 0.60-character relevance cutoff (retaining 21/177 characters and 38/55 taxa) and another at a 0.50 taxon relevance cutoff (176/177 characters and 20/55 taxa).
They also wanted to see if a statomorphic series could be observed, the authors did this analysis by finding first appearance datums (FAD).
“To understand stratomporhic relationships, cluster multivariate axis scores (e.g., first PCoA axis as an overall proxy) were binned against the first appearance datums (FAD), and regressed against conventional FAD, in order to test for stratomorphic series.”
The FAD were obtained from the PaleoBiology Database.
Multiple Correspondence Analysis (MCA) was used to calculate disparity, doing so gave valuable insights to say the least. The authors note:
“Assuming the nodosaurids and ankylosaurids form a single holobaramin, greater disparity and earlier appearance of nodosaurids than ankylosaurids (approx. 100 vs. 85 Ma conventional) suggests a bottom-heavy Ankylosauria holobaramin.”
Doran and McLain also noticed a strong stratomorphic series.
The specific details of the results and the methods can be found in the section “Biology abstracts” above.
Anyway, it would seem that Ankylosaurids evolved their tail club sometime after the Creation (assuming nodosaurids and ankylosaurids form their own holobaramin). I’m not 100% sure on assuming Ankylosauria as a single holobaramin, since Doran et al. 2018 showed possibly 2 holobaramins*. Granting the assumption listed above, it could explain as to why ankylosaurids had such a massive weapon if the Creation was initially an ideal world with no need to defend yourself from predators: they simply evolved it later, post-fall.
Granting this assumption, it would show that the most dispar taxa (the nodosaurids) were buried closer to the beginning of the flood than ankylosaurids and that the nodosaurids occupied a wider range of ecological niches than the ankylosaurids. This would also seem to show that the ankylosaurids were on the decline disparity-wise, a phenomenon noted by Romano 2021. These results would support his hypothesis.
If we could confirm Ankylosauria as a single holobaramin (which is probably unlikely), these would be significant results. If it doesn’t turn out to be the case that Ankylosauria is a single holobaramin, it would be an interesting discussion on why ankylosaurids stagnated disparity-wise.
Anyway, those are my thoughts. See the references below. And, yes, you can make fun of me for not completely understanding all of the statistics in this project.
*This part was originally "...4 holobaramins...", but was a mistake please see https://fossiltalk.blogspot.com/2022/08/correcting-error-i-made.html for the correction.
References
McLain, M.A. 2022. New Baraminological Analysis of “Basal” Pterosaurs Confirms Multiple Holobaramins. Journal of Creation Theology and Science Series B: Life Sciences 12:7-8.
Doran, N.A. and M. McLain. 2022. The Ankylosauria: A Bottom-Heavy Holobaramin? Journal of Creation Theology and Sciences Series B: Life Sciences 12:3-4.
Doran, N.A., M.A. McLain, N. Young, and A. Sanderson. 2018. The Dinosauria: baraminological and multivariate patterns. In: Whitmore, J.A., ed. Proceedings of the Eighth International Conference on Creationism. Creation Science Fellowship, Pittsburgh, PA, pp.404-457.
Romano, M. 2021. Disparity versus diversity in ankylosaurid dinosaurs: explored
morphospace indicates two separate evolutive radiations. Rendiconti Online della Società Geologica Italiana 53:1-7. https://doi.org/10.3301/ROL.2020.22
Zheng, W., J. Xingsheng, Y. Azuma, Q. Wang, K. Miyata, and X. Xu. 2018. The most basal ankylosaurine dinosaur from the Albian-Cenomanian of China, with implications for the evolution of the tail club. Scientific Reports 8:3711.
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