Forfexopterus: a Huanhepterus sister

Boy, it’s been a long time
since we’ve looked at a new pterosaur. Several months, perhaps… maybe longer…

Figure 1. Forfexopterus reconstructed. Note the metacarpals: 1>2>3, shared with Ardeadactylus. The rostrum tip is off the matrix.

Figure 1. Forfexopterus reconstructed. Note the metacarpals: 1>2>3, shared with Ardeadactylus. The rostrum tip is off the matrix. Note the difference between the actual fingers and the traced fingers by Jiang et al. The lack of precision in the Jiang et al. tracing, despite it being traced from a photograph, is a little disheartening.

Jiang et al. 2016
present a new disarticulated, but largely complete Early Cretaceous pterosaur, Forfexopterus jeholensis (Figs. 1–3). Jiang et al. consider their new find an ‘archaeopterodactyloid’ based on the ‘long metacarpus and reduced mt5’–but those are convergent traits in four pterodactyloid-grade clades. The large pterosaur tree (LPT) nests Forfexopterus near the base of the azhdarchid clade, which arises from the Dorygnathus clade, specifically nesting between Ardeadactylus and Huanhepterus + Mesadactylus (BYU specimen, not the anurognathid with the same name).

Figure 1. Forfexopterus original tracing, colors added.

Figure 2. Forfexopterus original tracing, colors added. See how simple colors ease the chaos of the roadkill fossil.

Unfortunately 
the Jiang et al. phylogenetic analysis suffers from taxon exclusion. They consider the Archaeopterodactyloidea to be composed of Germanodactylidae, Pterodactylus, Ardeadactylus. Gallodactylidae and Ctenochasmatidae. Those members are only monophyletic if the clade also includes Dorygnathus in the LPT, which was not the intention of the authors. It’s been awhile, but let us recall that the former clade “Pterodactyloidea” had four separate origins in the LPT, two from Dorygnathus (Ctenochasmatidae and Azhdarchidae) and the rest from Scaphognathus which was, in turn, also derived from Dorygnathus through several intervening transitional taxa.

Figure 2. Forfexopterus compared to sisters Huanhepterus and Ardeadactylus and the BYU specimen of Mesadactylus.

Figure 3. Forfexopterus compared to sisters Huanhepterus and Ardeadactylus and the BYU specimen of Mesadactylus.

Forfexopterus
has the slender proportions of Huanhepterus and Ardeadactylus. The rostrum was longer and lightened with several fenestra, one of which was likely a naris. Metacarpals 1–3 were longer medially, the opposite of basal pterosaurs. That trait lines up the joints in m1-3. Manual 4.2 is sub equal to m4.1, unique to this clade and atypical for pterosaurs in general.  Atypical for smaller members of this clade, but typical for larger members (like Jidapterus, but evidently not Huanhepterus (data comes from awkwardly produced original drawing)), the scapula was subequal to the coracoid and would have articulated with a notarium, which is not preserved, or is still largely buried (Fig. 2).

Shorthand suggestion (again)
There are two ways you can label a tetrapod phalanx:

  1. ph3d4 = phalanx 3, digit 4 (manus or pes? as shown in figure 2 above) or
  2. m4.3 = manual 4th digit, 3rd phalanx

Jiang et al. labeled their illustration using #1. You may find that method cumbersome and space consuming. I use and encourage others to use #2, the shorthand version.

When you check out the
Wikipedia page on Forfexopterus, the link to Archaeopterodactyloidea references three papers with Dr. Brian Andres as a co-author including his dissertation on
Sytematics of the Pterosauria. It’s great that PhD candidates tackle large projects. It’s hard work that makes them study their subject and prove their mettle. However, by definition, PhD candidates are not experts. They want to become experts by creating a dissertation, but they come to their projects naive, trusting the literature and beholding to their professors. These are all potential problems, as we talked about earlier.

In like manner, 
for my second paper (Peters 2000) I came to the project naive and trusting the literature. Judging from a vantage point, 17 years later, my observations were not those of an expert. Even so, I hit the mark with regard to pterosaur origins despite the many errors in that paper that have been corrected here and at ReptileEvolution.com. The nesting of pterosaurs apart from archosaurs and close to Macronemus, Tanystropheus, Langobardisaurus, Cosesaurus, Sharovipteryx and Longisquama has been validated and cemented by the large reptile tree (LRT). No other candidate taxa have ever been shown to be closer (= produce a gradual accumulation of derived traits). Attempts at correcting the observational errors in academic publications have been rejected by the referees who don’t want any more evidence published that pterosaurs are not dinosaur kin — or that tiny Solnhofen pteros are not babies.

Unfortunately
the Andres dissertation fails to produce a cladogram in which a gradual accumulation of traits can be traced in all derived taxa. For instance, anurognathids are basal to pterodactyloids in the Andres cladogram and the clade Archaepterodactyloidea was recovered. The Andres dissertation shortcoming can be attributed to taxon exclusion. By contrast, the LPT minimizes taxon exclusion by including many specimens ignored by Andres and other prior workers including multiple species within several genera and all those sparrow- and hummingbird-sized Solnhofen specimens. I know pterosaur workers are loathe to admit it, or recognize it, but those extra specimens are key to understanding pterosaur interrelations.

If you don’t look, you’ll never see.
If you don’t ask, you’ll never find out. Fellow pterosaur workers, don’t keep your blinders on. Expand your taxon lists to include a wider gamut of specimens.

This is Science.
When workers publish and referee allow manuscripts to be published they are judging the work fit for print. At that point they have stated their case. If the work stands up to rigorous scrutiny, then it will be cherished. If the work has flaws, then it’s up to fellow workers to expose those flaws for the good of Science.

References
Andres BBB 2010. Systematics of the Pterosauria. Dissertation. Yale University. p. 366.
Jiang S, Cheng X, Ma Y and Wang X 2016. A new archaeopterodactyloid pterosaur from the Jiufotang Formation of western Liaoning, China, with a comparison of sterna in Pterodactylomorpha. Journal of Vertebrate Palaeontology: e1212058.
Peters D 2000. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.

wiki/Forfexopterus
wiki/Archaeopterodactyloidea

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