2023 ‘Youngina capensis’ paper mistakenly described a different genus

Hunt et al 2023 wrote,
“The late Permian reptile Youngina capensis ( c . 254 Ma) is a non‐saurian neodiapsid whose anatomy has been used to represent the reptilian condition prior to the divergence of Sauria (crown‐group reptiles).”

Figure 1. The holotype of Youngina capensis is not congeneric with the BPI 2871 specimen studied by Hunt et al. Sometimes you have to trust labels. Some labels need to be tested. ” data-image-caption=”

Figure 1. The holotype of Youngina capensis is not congeneric with the BPI 2871 specimen studied by Hunt et al. Sometimes you have to trust labels. Some labels need to be tested.

” data-medium-file=”https://pterosaurheresies.files.wordpress.com/2024/03/youngina-amnh-5561-skull.jpg?w=181″ data-large-file=”https://pterosaurheresies.files.wordpress.com/2024/03/youngina-amnh-5561-skull.jpg?w=360″ class=”size-full wp-image-84751″ src=”https://pterosaurheresies.files.wordpress.com/2024/03/youngina-amnh-5561-skull.jpg?w=584″ alt=”Figure 1. The holotype of Youngina capensis is not congeneric with the BPI 2871 specimen studied by Hunt et al. Sometimes you have to trust labels. Some labels need to be tested.” srcset=”https://pterosaurheresies.files.wordpress.com/2024/03/youngina-amnh-5561-skull.jpg 360w, https://pterosaurheresies.files.wordpress.com/2024/03/youngina-amnh-5561-skull.jpg?w=90&h=150 90w, https://pterosaurheresies.files.wordpress.com/2024/03/youngina-amnh-5561-skull.jpg?w=181&h=300 181w” sizes=”(max-width: 360px) 100vw, 360px” />

Figure 1. The holotype of Youngina capensis is not congeneric with the BPI 2871 specimen studied by Hunt et al. Sometimes you have to trust labels. Some labels need to be tested.

There are several problems here. all due to taxon exclusion.
The BPI 2871 specimen the authors used (Fig 1) is not related to Youngina capensis the holotype AMNH 5561 (Fig 1). The two are separated by other genera the LRT (Fig 2). The BPI specimen is transitional from proterosuchids to choristoderes and so represents a different chapter in the reptile story.

By contrast the AMNH specimen was basal to proterosuchids.

“However, despite being first described over 100 years ago, the anatomy of Youngina remains incompletely documented.’

So, don’t document the wrong taxon. It’s like their headline was about Superman, but their text was about Batman. Document Youngina, AMNH 5561, the holotype (Fig 1). The BPI specimen is different: a relative of Elachistosuchus huenei  leading toward choristoderes. If you are going to discuss the BPI specimen, then talk about how it was transitional to choristoderes.

“Here we use synchrotron x‐ray micro‐computed tomography to document new features of the palate, braincase and mandible of Youngina. New observations include an anteriorly bifurcating vomer, dentition on the ventral surface of the parasphenoid body and cultriform process, and a strongly convex coronoid eminence. Our anatomical observations suggest that Youngina may represent a more stemward lineage among non‐saurian neodiapsids and this is supported by our phylogenetic analysis, which places Youngina as an early diverging neodiapsid.”

Pretty vague. The LRT resolved this taxon and several other related taxa by expanding the taxon list.

“Our research will benefit future studies on saurian origins by providing improved constraints on neodiapsid anatomy prior to the divergence of the reptilian crown group.”

These authors don’t realize (due to taxon exclusion) that the diapsid skull grade occurred twice by convergence, once in the Lepidosauromorpha (Paliguana and descendants) and once in the Archosauromorpha (Petrolacosaurus and descendants). Taxon exclusion, borrowing out-dated cladgrams and trusting old textbooks unnecessarily hobbles  this otherwise potentially good work.

The authors also don’t realize (due to taxon exclusion) that several specimens attributed to Youngina,  Youngoides and Youngolepis must ALL be included in analysis… not just one. It’s the same problem with Archaeopteryx vs the dozen Solnhofern birds. Use them all.

Figure 2. Subset of the LRT encompassing all taxa beginning with the phrase ‘Young’, including the holotype of Youngina capensis and the unrelated specimen that Hunt et al studied. ” data-image-caption=”

Figure 2. Subset of the LRT encompassing all taxa beginning with the phrase ‘Young’, including the holotype of Youngina capensis and the unrelated specimen that Hunt et al studied.

” data-medium-file=”https://pterosaurheresies.files.wordpress.com/2024/03/youngininiformes-hunt588.jpg?w=77″ data-large-file=”https://pterosaurheresies.files.wordpress.com/2024/03/youngininiformes-hunt588.jpg?w=263″ class=”size-full wp-image-84753″ src=”https://pterosaurheresies.files.wordpress.com/2024/03/youngininiformes-hunt588.jpg?w=584&h=2276″ alt=”Figure 2. Subset of the LRT encompassing all taxa beginning with the phrase ‘Young’, including the holotype of Youngina capensis and the unrelated specimen that Hunt et al studied.” width=”584″ height=”2276″ srcset=”https://pterosaurheresies.files.wordpress.com/2024/03/youngininiformes-hunt588.jpg?w=584&h=2276 584w, https://pterosaurheresies.files.wordpress.com/2024/03/youngininiformes-hunt588.jpg?w=77&h=300 77w, https://pterosaurheresies.files.wordpress.com/2024/03/youngininiformes-hunt588.jpg 656w” sizes=”(max-width: 584px) 100vw, 584px” />

Figure 2. Subset of the LRT encompassing all taxa beginning with the phrase ‘Young’, including the holotype of Youngina capensis and the unrelated specimen that Hunt et al studied.

Don’t borrow untrustworthy, cherry-picked cladograms.
Build your own LRT so you’ll write your next paper with authority and validity… and don’t omit pertinent taxa, especially the one in your headline.

References
Hunt AK, et al (4 co-authors) 2023. A description of the palate and mandible of Youngina capensis (Sauropsida, Diapsida) based on synchrotron tomography, and the phylogenetic implications. Papers in Paleontology 9(5): DOI: 10.1002/spp2.1521

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