Another overlooked turtle ancestor just got published

Considered
congeneric with Elginia mirabilis (from Late Permian Scotland), the new elginiid comes from Late Permian China (Figs. 1, 2). The authors (Liu and Bever 2018) correctly identified the material in a specific sense, but had no idea what they had in a broader sense, because they only tested Elginia against pareiasaurs.

It’s really part of the genesis of turtles (Fig. 2), and we’re glad to see it!

Once again,
taxon exclusion raises its blind head. We’ve known Elginia was a turtle ancestor since 2014 when that went online. Unfortunately co-author Bever had earlier published on the genesis of turtles, relying on pre-turtle-mimic Eunotosaurus. Both are tested in the large reptile tree (LRT, 1152 taxa) and Eliginia nests with turtles. Eunotosaurus does not. It is more closely related to Acleistorhinus and kin. When Liu and Bever include Meiolania and Niolamia (Fig. 2) in their analyses, then they’ll see how it all plays out.

Elginia wuyongae (Figs. 1, 2) is smaller than Elginia mirabilis, lacks long horns and nests between the big desert pareiasaur, Bunostegos (Fig. 2), and its Scottish namesake at the base of hard shell turtles. Importantly, E. wuyongae preserves a few post-cranial data, including the genesis of the hard-shell turtle carapace…which is incredible news!!!

But you’re hearing that here first.
Jiu and Bever did not understand the importance and so overlooked it.

Figure 1. Elginia wuyongae was just described. It shows the genesis of shell formation in hard shell turtles.

Figure 1. Elginia wuyongae was just described. It shows the genesis of shell formation in hard shell turtles. That tiny last sacral vertebra (near the four dots) suggests a tiny tail was present. 

Lacks a rostrum…
skull is pretty beaten up, parts missing, holes pocket bones, lacks a palate. Squamosal misidentified originally (repaired here). Still, you gotta love it! It has post-cranial clues lacking in other transitional taxa. And it fills a gap!

How can workers not notice the family resemblance? 

Figure 2. Another gap is filled by nesting E. wuyongae between Bunostegos and Elginia at the base of hard shell turtles in the LRT.

Figure 2. Another gap is filled by nesting E. wuyongae between Bunostegos and Elginia at the base of hard shell turtles in the LRT. Those other horned pareiasaurs are basal turtles, meiolaniids with substantial carapace and plastron. Both sides of the new Elginia skull are shown. The squamosal is tucked inside the overlapping supratemporal in these transitional taxa. 

The authors do mention the turtle connection, like so:
“…and their long-hypothesized, but now largely rejected, potential as the close relatives
of turtles (Rieppel & deBraga 1996; Lyson et al. 2010; Lee 2013; Lyson et al. 2013; Bever et al. 2015; Schoch & Sues 2015; Laurin & Pi~neiro 2017).” It’s not surprising how many workers think this – because they don’t test the taxa that need to be tested, as they are tested here in the LRT. Remember, a consensus of workers can be wrong.

On that note:
Liu and Bever are still clinging to the invalid clade Parareptilia.

References
Liu J and Bever GS 2018. The tetrapod fauna of the upper Permian Naobaogou formation of China: A new species of Eliginia (Parareptilia, Pareiasauria). Papers in Paleontology 2018: 1-13.

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