Euparkeria and the origin of birds… and pterosaurs

You would never think that paleontologists would stoop so low
as to consider Euparkeria (Fig. 1) in the origin of birds, especially when they had excellent specimens in hand of the feathered theropod, Archaeopteryx, since the 1860s.

But they did.

At least there was ‘an argument’ in the clavicle-loss hypothesis.
Even though that was committing the sin of “Pulling a Larry Martin“, that was at least something workers could use in their arguments.

Nowadays, thankfully,
no one uses Euparkeria in bird origin studies. That’s because we know better now. And no one wants to look foolish in the eyes of their peers.

On a similar note…

You would never think that paleontologists would stoop so low
as to consider armored Euparkeria (Fig. 1) in the origin of pterosaurs, especially with excellent specimens in hand of the flapping fenestrasaurs, Cosesaurus, Longisquama and Sharovipteryx (Fig. 2). These taxa have prepubes, sternal complexes, antorbital fenestrae, hollow bones, pterosaurian lateral toes, simple hinge ankles, elongated ilia, more than three sacrals, attenuated tails, strap-like scapulae, stem-like and locked down coracoids (for flapping), long manual digit 4s (for flappiing while bipedal) and various extradermal membranes including uropatagia (Peters 2000).

Nevertheless,
many pterosaur workers since 2003 used and continue to use Euparkeria as an outgroup taxon in analytical studies (e.g. Vidovic and Martill 2017). They don’t feel the need to provide an argument to support their choice. They choose to use Euparkeria and refuse to consider competing candidate taxa. That’s a problem perpetuated in university textbooks. Many perosaur workers appear reluctant to leave Euparkeria in the dust. Apparently they prefer that comfort rather than the submit to the peer group discomfort of using (or even testing) fenestrasaur ancestors of pterosaurs (Fig. 2), even though they know that’s their job: to test competing hypotheses.

A recent exception: Ezcurra et al. 2020
created a chimaera from lagerpetid and protorosaur bits and pieces, then called it a pterosaur precursor close to dinosaurs. Euparkeria was not mentioned in the text and no reason was given for its omission.

This example only shows things are getting worse, not better.
Workers are still cherry-picking outgroup taxa for dinosaurs and pterosaurs. They are not letting software choose outgroups for pterosaurs and dinosaurs from a wide gamut of candidate taxa. They are purposefully omitting fenestrasaurs even though fenestrasaurs are in the literature. Taxon exclusion continues to be the number one problem in paleontology. And it is self-inflicted.

References
Chiappe LM and Dyke GJ 2006. The early evolutionary history of birds. Journal of the Paleontological Society of Korea 22(1):133-–151.
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 unpublished. Cosesaurus aviceps, Sharovipteryx mirabilis and Longisquama insignis Reinterpreted. ResearchGate.org PDF
Vidovic SU and Martill DM 2017. The taxonomy and phylogeny of Diopecephalus kochi (Wagner, 1837) and ‘Germanodactylus rhamphastinus’ (Wagner, 1851). From: Hone DWE., Witton MP and Martill DM (eds) New Perspectives on Pterosaur Palaeobiology. Geological Society, London, Special Publications, 455, https://doi.org/10.1144/SP455.12