It’s a conundrum
how workers name pterosaurs. No two adult Rhamphorhynchus are phylogenetically identical. No two Dorygnathus. No two Germanodactylus. No two Pteranodon, etc. Until a few decades ago there was more lumping than splitting. Now there is more splitting than lumping with many new names erected for new specimens on shaky grounds. Why?
Campos 2021 created a new genus,
Javelinadactylus sagebieli, for a latest Cretaceous tupuxuarid rostrum, TMM 42489-2. So it’s in the literature now. We looked at this specimen (Fig. 1) several years earlier here.
In order to test the affinities of Javelinadactylus
Campos borrowed a .nex file employing a paltry 57 taxa and 144 characters. That compares with the 4.5x larger large pterosaur tree (LPT) which currently tests 259 taxa with 183 characters.
Campos’s cladogram reflects current university teaching that supports Benton 1999, who determined that the tiny bipedal crocodylomorph with tiny hands and no pedal digit 5, Scleromochlus, was the proximal pterosaur ancestor (Fig. 2), and Late Jurassic Anurognathus (Fig. 2) was the basalmost pterosaur.
but this is what they have been teaching for the last two decades. Look at the hands (Fig. 2). Look at the feet. A vestige turning into a robust wing doesn’t matter to the followers of professor Benton. It just doesn’t matter.
in the large reptile tree (LRT, 1890+ taxa) the last common ancestor of Anurognathus and Scleromochlus is the basalmost reptile (= amniote). That means, when you add taxa, Anurognathus and Scleromochlus are as unrelated as possible within the clade Reptilia.
This is why you should think twice
about going to a university to study pterosaur paleontology. Students and post-grads are under pressure from professors and their peers (= other professors) to follow the status quo, (= borrow earlier cladograms) even if results are untenable (Fig. 2) and taxon lists are way too short. Academic authors are also under pressure to ignore independent authors (= outside the university system).
Getting back to Javelinadactylus…
as you can see (Fig. 1) there is no generic difference between it and Tupuxuara from the Early Cretaceous. So, the real story here should have been: this is the first genus of pterosaur to survive for so many tens of millions of years.
that story line goes away since Campos 2021 gave the specimen a new generic name. The questtion is: Was the new name deserved?
Let’s look at the scores in the Campos matrix
After examination, all scores that could be scored in the Campos matrix were identical for Javelinadactylus and Tupuxuara — except for three:
20) Campos found a gap between the jaws during occlusion for Javelinadactylus, but not for Tupuxuara. Looks like (Fig. 1) that trait was present in both, but you decide.
26) On the same trait (Fig. 1), Campos found a distinct concavity on the occlusal surface of the rostrum on Javelinadactylus, but not on Tupuxuara. Same answer?
80) Campos found the dentary had an ossified sagittal crest on Javelinadactylus, but not on Tupuxuara. Take a look (Fig. 1). The same ventral crest is present on both taxa.
Identical scores usually mean conspecific and congeneric taxa.
That’s how the first juvenile Rhamphorhynchus was recovered in phylogenetic analysis. Are these three questionable scores in Campos 2021 enough to erect a new genus? I was hoping for more…The academic referees were content to let this slide. As we saw earlier with Darren Naish, academics relish criticising outsiders, but fail to criticise fellow academics.
Campus 2021 wrote,
“The new specimen described here represents the first record of the Tapejaridae group in the Maastrichtian of North America, and the cranial morphology of the new taxon increase the richest of the diversity of the azhdarchoid pterosaurs during the end of the Late Cretaceous, suggesting that the tapejarids were still diversifying in the Maastrichtian.”
currently popular cladograms, like the one Campos borrowed, employ too few taxa. We’ve known since Peters 2007 that adding taxa separates tapejarids from azhdarchids. Thus the traditional clade “Azhdarchoidea” has been polyphyletic for fifteen years. Colleagues, give it a rest. Click here for an uncited and unused pterosaur cladogram that includes more than enough taxa to separate these two dissimilar clades. You won’t find outgroup taxa from Campos in the LPT, but if you are looking for Herrerasaurus, Ornithosuchus and Scleromochlus they are all here in the LRT.
If you think science is all about
unbiased data, think again. Too often in vertebrate paleontology it’s a feudal system with professors acting as lords and gatekeepers. Campos played the game and got published. He’s trying to make paleontology his profession. I’m not under the same pressures, so I have the freedom to add taxa and point out potential issues.
For more academic shenanigans
you can click here to see how Dr. David Hone followed orders to get his PhD from his co-author and mentor, Dr. Michael Benton. (Yes, the same Dr. Benton mentioned above.)
Benton MJ 1999. Scleromochlus taylori and the origin of the pterosaurs. Philosophical Transactions of the Royal Society London, Series B 354 1423-1446. Online pdf
Campos HBN 2021. A new azhdarchoid pterosaur from the Late Cretaceous Javelina Formation of Texas. Biologia. https://doi.org/10.1007/s11756-021-00841
Peters D 2000. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Peters D 2007. The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27.