O’Connor and Marugán-Lobón ‘suggest’ that all known Solnhofen avialans represent Archaeopteryx

With few exceptions,
college textbooks and workers have long considered all the feathered theropods from Solnhofen limestones (Late Jurassic, Southern Germany) to be members of the same genus, Archaeopteryx . So much so, that ‘Archaeopteryx‘ has become a brand name with more value (for headlines, manuscripts and museum tickets) than if the taxa were separated with less reknown generic and specific names.

Most prior workers were ‘lumpers’.

After phylogenetic analysis
the large reptile tree (LRT, 2340 taxa) split most (not all) of the Solnhofen birds apart and lumped them into distinct and separate clades.

Thus the LRT is both a ‘lumper’ and a ‘splitter’.

A recent paper
by O’Connor and Marugán-Lobón 2026 acknowledges the variation, but concludes, ‘all known Solnhofen avialans represent Archaeopteryx’.

These two authors are also lumpers.

The authors reported
on the first line of their Introduction, “Archaeopteryx is arguably one of the most important and highly studied fossil taxa.”

So the authors are more than aware of the brand name value.

Citing Wellnhofer 2009, the authors reported,
“Nearly every known specimen has been assigned a unique taxonomic identity at some point in its history.”

So, that’s the splitter side of the argument.

Citing Rauhut, Foth and Tischlinger 2018, the authors reported,
“In a recent study including a revised diagnosis for the genus, all well-preserved specimens were considered referrable to Archaeopteryx.”

So, that’s the lumper side of the argument.

The authors reported,
“Several previous morphometric analyses have concluded that sampled specimens form an allometric growth curve.The recent discovery of significant new material (six new specimens since 2005) warrants re-examination of all known specimens of Solnhofen avialans.”

The authors are hinting that they are not going to run
a wide-gamut phylogenetic analysis.

Under the Methods section, the authors reported,
“Length measurements were obtained for all 15 Solnhofen avialans from the literature.  Twelve measurements were selected based on preservational limitations to maximize available data. Measurements for Anchiornis were also taken from the literature. Only three specimens preserved all measured elements.”

Does anyone see the flaw in this exclusive method?

Under the Discussion section, the authors reported,
“Morphometric analysis of all 15 known avialan fossils from the Solnhofen Limestone indicates that proportionately, these specimens fit consistently in a growth curve. If more than one taxon is present as has been suggested, they share the same limb-scaling pattern for a given size, which does not support the hypothesis that non-avian  anchiornithine avialans, archaeopterygid avians and non-archaeopterygid avians are all represented by this sample.”

Maybe they do share the same limb-scaling pattern for a given size. Maybe that was ideal for their circumstances.

To my eye, their chart (their figure 2) shows a scattering, not a lumping, with the Chicago specimen, near and dear to the heart of author J O’Connor, lumping at far left with the Eichstätt specimen, far from the Solnhofen and London specimens at right and right center respectively.

Maybe other traits, perhaps in the skull, split taxa.

Maybe this paper should have tested omnitted taxa just to see if any Solnhofen birdds were more attracted to other birds than to each other, instead of dismissing the possibility. If the LRT can do it for free, then professional paleontologists who are paid to do it ought to do it. Beware whenever any scientist dismisses a possibility without testing it.

If the authors only measured Solnhofen birds,
without including potential rivals for closer interrelationships in phylogenetic analysis, then of course they would conclude their results represented a growth curve. The LRT tests most of these taxa – and many outside taxa – and finds that some nest together and others do not. Several Solnhofen taxa prefer to nest with taxa basal to other clades from around the world, indicating there was a variety of early birds with bony tails and teeth in the Solnhofen lagoons.

I think the authors missed a great opportunity.

See for yourself here and here and here.

Getting back to Dr David Hone’s earlier lament
about having to include a phylogenetic analysis when introducing new taxa – evidently that referee request is inconsistently applied. It was not applied in the case of this paper on Archaeopteryx, where it was most needed.

Further studies and earlier comments:

https://pterosaurheresies.wordpress.com/2023/07/29/archaeopteryx-ontogeny-paper-authors-decided-not-to-run-a-phylogenetic-analysis/

https://pterosaurheresies.wordpress.com/2018/10/26/the-daiting-specimen-is-not-archaeopteryx/

https://pterosaurheresies.wordpress.com/2025/05/15/chicago-archaeopteryx-published-in-nature/

Thanks to reader, Stu,
for bringing this paper to my attention.

References
O’Connor J and Marugán-Lobón J 2026. Evaluating variation in Solnhofen avialans. Biol. Lett. 22: 20250601. https://doi.org/10.1098/rsbl.2025.0601
Wellnhofer P 2009. Archaeopteryx: the icon of evolution. Munich, Germany: Verlag Dr. Friedrich Pfeil.

Source: https://pterosaurheresies.wordpress.com/2026/03/25/oconnor-and-marugan-lobon-suggest-that-all-known-solnhofen-avialans-represent-archaeopteryx/