SVP 2022 abstracts – 2 and 3 on pterosaur origins and radiations

2. Climate drivers of early pterosaurs: Foffa et al 2022 wrote:
“Pterosaurs were the first vertebrates to evolve powered flight and were major components of Mesozoic terrestrial ecosystems. However, their origin is still poorly understood, due to a stratigraphic and morphological gap between these reptiles and their closest relatives, the lagerpetids.”

This is so sad.
Sad because these workers are looking in the wrong place for pterosaur ancestors. Here in the Midwest of the USA this is called ‘snipe hunting.’

A snipe hunt is a type of practical joke or fool’s errand, in which an unsuspecting newcomer is duped into trying to catch a nonexistent animal called a snipe. Although snipe are an actual family of birds, a snipe hunt is a quest for an imaginary creature.

If the PhDs are doing this on purpose
or for the student’s tuition money it’s just as bad as if they didn’t know any better, or they do know better, but are bowing to peer group pressure.

Workers and readers:
do not add to the ongoing myth of pterosaur origins and their invalidated archosaur affiliations. Lagerpetids are proterochampsids close to Tropidosuchus. Pterosaurs are lepidosaurs close to Cosesaurus, Macrocnemus and Huehuecuetzpalli in the LRT. Taxon exclusion is the issue here. Do not be a party to tradition, peer group pressure or willful negligence.

I sent this note to lead author Davide Foffa several weeks ago:
“You’re looking for an outgroup taxon to Pterosauria. OK. Look for a taxon with a long finger four and a long toe five, like Cosesaurus. These traits are not found in archosaurs. Look for a sternal complex (clavicle + interclavicle + sternum) as in Cosesaurus, Look for a taxon with extradermal membranes trailing the forelimbs and hind limbs, as in Cosesaurus. Look for a taxon with a locked-down quadrant-shaped coracoid, as in Cosesaurus. That means, as it does in birds, that flapping is present, whether volant or not. Look for a pteroid and prepubis, as in Cosesaurus. Look for a taxon with an attenuated tail, almost lacking caudofemoral musculature, replacing that with an anteriorly elongate ilium held together with 4-5 sacral vertebrae, as in Cosesaurus.

Some pertinent web pages are here:

http://reptileevolution.com/cosesaurus.htm

http://reptileevolution.com/reptile-tree.htm

“Then there’s the issue of pterosaurs themselves. Again, add taxa and several clades you wrote about go away, replaced by others. For instance, ‘Pterodactyloidea’ is now a grade with four separate origins and two other clades approaching that grade. Cladogram here:

http://reptileevolution.com/MPUM6009-3.htm

“Best regards, and let me know if I can be of any further help.”

3. Origins of Pteroauria: Fitch et al 2022 wrote,
“Debate exists as to whether Triassic and Jurassic pterosaurs represent larger, monophyletic subclades or a series of successive sister taxa to Monofenestrata (pterodactyloids and pterodactyloid-like forms). Reexamination of early ornithodirans and of the ‘eudimorphodontoid’ pterosaur Arcticodactylus cromptonellus show a mosaic of lagerpetid and pterosaur features.”

Again, these students and their PhD guides are looking in the wrong place (lagerpetids) for pterosaur outgroups. Ornithodira is a junior synonym for Reptilia in the LRT. No pterosaur shows any lagerpetid features except by convergence.

“Eudimorphodontoidea/ Raeticodactyloidea, Dimorphodontidae, and Scaphognathidae/ Rhamphorhynchidae are recovered as respectively paraphyletic to each other and Monofenestrata, decreasing or eliminating many early pterosaur ghost lineages.”

Distrust all cladograms that nest suprageneric taxa. Use genus-based and specimen-based taxa, like the large pterosaur tree (LPT, 264 taxa). ‘Monofenestrata‘ is paraphyletic because at least five clades achieve this trait.

“We find only a single pterosaur lineage crossed the Triassic-Jurassic and Early-Middle Jurassic biotic transitions, the former of the ‘dimorphodontid’ grade (large-headed terrestrially adept forms) and the latter of the ‘rhamphorhynchid/scaphognathid’ grade (aerial predators).”

Confused here. Only a single lineage? The ‘former‘ and the ‘latter‘ = two lineages.

“These results demonstrate a clear loss of diversity in early Pterosauria (here approaching extinction) with the loss of all but one pterosaur lineage akin to losses found in other groups that crossed the end Triassic and Early-Middle Jurassic biotic transitions into the late Mesozoic.”

Add taxa. Don’t be lazy. Results will differ when you do.
Final question: Which was the “one pterosaur lineage” that made it through? Try to give results in your abstracts. There’s no need to be teasing readers (e.g. “hidden fossil record”) to get them to attend your presentation. The title should have been “Radiations of Pteroauria” based on the abstract.

References
Fitch AJ et al (5 co-authors) 2022. Origins of Pterosauria: hidden fossil fossil record and near extinction of the first and longest-lasting flying vertebrate lineage revealed through a new phylogenetic hypothesis. SVP 2022 abstracts: 43.
Foffa D et al (11 co-authors) 2022. Climate drivers of early pterosauromorph evolution. SVP 2022 abstracts: 43.