Sinomacrops part 2: more problems and insights

Yesterday we looked at only some of the problems identifying parts of the new anurognathid from China, Sinomacrops bondei (Wei et al. 2021, JPM 2012-001). Here are more. It’s not good that PhDs are making mistakes that are so obvious an amateur can pick them out.

the ‘macrops’ portion of Sinomacrops means ‘large eyes’, a myth trait originated with Bennett 2007 when he misidentified a maxilla as a scleral ring. No such large scleral ring is present in Sinomacrops or any anurognathid. Two scleral rings are present in Sinomacrops and they both appear in the posterior half of the skull, as in other anurognathids, as shown yesterday. This myth persists because workers are unwilling to commit themselves to reconstructing skulls and skeletons of anurognathids. That would make them liable for all mistakes. But that’s a good thing in science! Reconstructions are part of the DGS process of color tracing here (Fig. 3). I make corrections to mistakes ALL the time.

With regard to wing tissue, Wei et al. report,
“An irregular patch of soft tissue lateral to the left tibiotarsus suggests that the brachiopatagium extended posteriorly onto the distal region of the crus. A brachiopatagium extending distally on the crus is consistent with what is seen in Jeholopterus ningchengensis (see Kellner et al., 2010) and pterosaurs in general (see Elgin, Hone & Frey, 2011).”

Figure 1. That irregular patch of soft tissue lateral to the tibia is indeed wing tissue, but torn from the distal wing phalanges, which are right there! And isn’t that a wonderful wing ungual!

That “irregular patch” is a bit of distal brachiopatagium torn from the distal wing phalanges (Fig. 1). Likewise, Jeholopterus does not preserve a brachiopatagium lateral to the tibia. Elgin, Hone and Frey 2011 totally botched their interpretations with cartoony outlines. Remember their ‘shrinkage‘ solution when the evidence clearly invalidated their assertion? Wei et al. did not cite Peters 2002, who presented in sharp detail several examples of a pterosaur brachiopatagia (including Jeholopterus) that was stretched only between the wingtip and elbow (Fig. 1a). That’s just the way it is! Stop imagining and stop pretending it’s something else.

Figure 1a. All pterosaurs with soft tissue preserve this morphology: a wing stretched between elbow and wing tip with fuselage fillets medial to the elbows. The hind limbs are independent and act as horizontal stabilizers, as in many airplanes.

don’t overlook that wonderful wing tip ungual in figure 1. PhDs overlook that ungual. It’s part of their creed, evidently.

Wei et al. report only two apomorphies
(we call this “Pulling a Larry Martin“. One of them is “tibiotarsus twice as long as the femur.” Let’s see if the tibia is indeed twice as long as the femur.

FIgure 2. The tibia of Sinomacrops is not twice as long as the femur, contra Wei et al. 2021.

After testing, the tibia is not twice as long as the femur. It is twice as long as only part of the femur. Please have someone tell Wei et al. there is no tibiotarsus in pterosaurs, only in dinosaurs.

Wei et al. did not look closely enough
to see that the trait: ‘medial unguals larger than lateral unguals on both manus and pes’ is the sort of apomorphy they were looking for.

Figure 3. Left: Life restoration of Sinomacrops from Wei et al. 2019 filled with problems. Center: Skeletal of Sinomacrops from fossil tracings. Right: Anurognathus holotype for comparison to scale. Note the smaller feet and more robust humerus in Sinomacrops.

Phylogenetic problems
Here’s how the large pterosaur tree (LPT) nested Sinomacrops, alongside Anurognathus (Fig. 3). This clade nests securely in the LPT with non-pterosaur outgroup taxa and several Triassic taxa, like the basalmost pterosaur, long-legged Bergamodactylus, a taxon omitted by Wei et al.

Figure 4. The LPT nests Sinomacrops, from China, alongside Anurognathus, from Germany. Other pterosaurs have anarrow snout and nest elsewhere.
Figure 5. From Wei et al. 2021. They separate dimorphodontids from similar anurognathids and omit dozens of pertinent taxa. They nest Sinmacrops with Batrachognathus.
Figure 6. Wei et al. present several past cladograms showing the variety of nesting sites for anurognathids. All have their faults due to taxon exclusion. Note that none include pterosaur outgroup taxa.
Figure 7. Click to enlarge: Yes, one embryo anurognathid is the size of other adult anurognathids, making the adult 8x larger.

With the publication of Simacrops
several pterosaur myths continue without evidence, promoted by PhDs. No one wants to admit that giant eyeballs cannot be found in the front half of anurognathid skulls. No one wants to admit there is no evidence for pterosaur wing membranes attached to the ankles. No one wants to admit tiny Solnhofen pterosaurs and dozens of other traditionally omitted specimens into their cladograms, nor do they want to admit Cosesaurus and kin in as pterosaur ancestors. Who will be the first to break from these academic strangleholds? Who will suffer for doing so?

Worth noting the backlog.
Wei et al. 2021 appears three years after the Flugsaurier 2018 abstract. If you’re planning on publishing, expect that sort of wait and delay after your manuscript and figures are finished. In counterpoint, blogposts published on the WWWeb are presented within hours.

Mea culpa.
Yesterday I did not realize it, but we first looked at Sinomacrops back in 2018 when it appeared in a Flugsaurier abstract, before the specimen had a name. The hi-rez images provided by Wei et al. 2021 improved data, but back then, when Sinomacrops was known as JPM 2012-001, it also nested with Anurognathus in the LPT. Yesterday, I must admit, I looked at the specimen and thought it looked familiar, but did not remember I had already traced it three years ago.

Correcting earlier errors
and fine-tuning earlier interpretations is all within the realm of science. Deliberately supporting invalid myths, ignoring taxa and omitting citations is not so good. It only comes back to bite you in the end. Don’t omit citations. Fight invalid assumptions with valid evidence, not the wishful thinking employed by Bennett, Wei et al, Elgin, Hone and Frey, etc.

Bennett SC 2007. A second specimen of the pterosaur Anurognathus ammoni. Paläontologische Zeitschrift 81(4):376-398.
Elgin RA, Hone DWE and Frey E 2011. The extent of the pterosaur flight membrane. Acta Palaeontologica Polonica 56 (1), 2011: 99-111. doi: 10.4202/app.2009.0145
Lü J-C, Zhou X-Y, Liu C-Y and Sun D-Y 2018. Chinese anurognathid pterosaurs. Flugsaurier 2018: the 6th International Symposium on Pterosaurs. Los Angeles, USA. Abstracts:63-65.
Peters D 2002. A New Model for the Evolution of the Pterosaur Wing – with a twist. – Historical Biology 15: 277–301.
Wei X, Pêgas RV, Shen C, Guo Y, Ma W, Sun D, Zhou X. 2021. Sinomacrops bondei, a new anurognathid pterosaur from the Jurassic of China and comments on the group. PeerJ 9:e11161


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