The Daiting specimen is not Archaeopteryx

Today
a break from a review of the SVP 2018 abstracts.

A new paper by Kundrát, et al. 2018
re-describes the Daiting specimen (Tischlinger 2009) attributed to Archaeopteryx and given a specific name A. albersdorfi (SNSB BSPG VN-2010/1Kundrát et al. 2018, Late Jurassic, Lower Tithonian; Figs. 1, 2). 

Figure 1. The Daiting specimen attributed to Archaeopteryx in white and UV light. Note the short coracoid. This is not a flapping tetrapod.

Figure 1. The Daiting specimen attributed to Archaeopteryx in white and UV light. Note the short coracoid. This is not a flapping tetrapod.

The skull of the Daiting specimen
is newly reconstructed here (Fig. 2). The former postorbital is now the squamosal. The former squamosal is here identified as three bones layers atop one another. The bones of the mandible are newly interpreted here.

Figure 2. The skull of the Daiting specimen wrongly attributed to Archaeopteryx reconstructed from µCT scans.

Figure 2. The skull of the Daiting specimen wrongly attributed to Archaeopteryx reconstructed from µCT scans. Some bones are reidentified here.

Unfortunately,
the large reptile tree (LRT, 1313 taxa; subset Fig. 3) nests the Daiting specimen outside of the birds, between Sinovenator and Xiaotingia.

Figure 3. Subset of the LRT focusing on basal birds and pre-bird theropods. Note many of the various Solnhofen birds nest apart from one another and the Daiting specimen nests outside the birds (Aves).

Figure 3. Subset of the LRT focusing on basal birds and pre-bird theropods. Note many of the various Solnhofen birds nest apart from one another and the Daiting specimen nests outside the birds (Aves). Preview: note the nesting of the four included Anchiornis specimens. 

Kundrát et al. provided several cladograms
based on data sets provided by Xu et al. 2011; Turner et al. 2012 and Godefroit et al. 2013. They “unanimously resolved [the Daiting specimen] as both a basal avialan and an archaeopterygid, but does not unequivocally discriminate between a paraphyletic or monophyletic Archaeopteryx.” 

  1. Xu et al. 2011 cladogram: nests the Daiting specimen between Anchiornis + Xiaotingia and Archaeopteryx + Wellnhoferia, all derived from SapeornisYanornis clade.
  2. Xu et al. 2011cladogram (Xiaotingia deleted): nests the Daiting specimen between a SapeornisYanornis clade and Archaeopteryx + Wellnhoferia,
  3. Turner et al. 2012 cladogram: nests the Daiting specimen basal to a different Sapeornis clade, all derived from Archaeopteryx.
  4. Turner et al. 2012 cladogram (3 taxa deleted): nests the Daiting specimen basal to a different Sapeornis clade, all derived from Archaeopteryx.
  5. Godefroit et al. 2013 cladogram: nests the Daiting specimen with Archaeopteryx, basal to the BalaurRahonavis clade, all derived from Xiaotingia.

Not all of the nodes in the above cladograms
include a gradual accumulation of traits in all derived taxa.

Kundrát et al. report:
“Archaeopteryx albersdoerferi is the only Bavarian archaeopterygid that exhibits co-ossification of the carpals and metacarpals, differing from modern flying birds in that the distal postaxial carpal (usually missing – perhaps cartilaginous – in other archaeopterygid specimens; (Wellnhofer 2009)) co-ossified with the metacarpal of the major digit rather than with the semilunate and postaxialmetacarpal.”

“The most noteworthy feature of Archaeopteryx albersdoerferi is that it accummulated several characteristics of maturity (discussed above) during the juvenile period of ontogeny that were not seen either in smaller or in larger specimens of Archaeopteryx lithographica.”

The coracoids of the Daiting specimen
are still rather disc-like in appearance, not strap-like as in Xiaotingia and birds. The Daiting specimen was not a flapping taxon, or not a good flapping taxon. That comes at the next node.

Figure 4. Pectoral girdle of the Daiting specimen wrongly attributed to Archaeopteryx showing the clavicle (cv=furcula), scapula (sc), and the disc-like coracoids (co). Strap-like coracoids occur in more derived taxa and this shape marks the genesis of flapping.

Figure 4. Pectoral girdle of the Daiting specimen wrongly attributed to Archaeopteryx showing the clavicle (cv=furcula), scapula (sc), and the disc-like coracoids (co). Strap-like coracoids occur in more derived taxa and this shape marks the genesis of flapping.

Earlier we looked at the variety of taxa present in Solnhofen birds,
(Fig. 3, 5) all of which have been called Archaeopteryx at their first publication. Later authors have renamed several of them. Remember, you can’t determine a genus or species without the context of a phylogenetic analysis.

Figure 3. Several Solnhofen birds, including Archaeopteryx, compared to Ostromia to scale.

Figure 5. Several Solnhofen birds, including Archaeopteryx, compared to Ostromia to scale.

References
Kundrát M, Nudds J, Kear BP, Lü J-C and Ahlberg P 2018. The first specimen of Archaeopteryx from the Upper Jurassic Mörnsheim Formation of Germany. Historical Biology 31(1):3-63.
Tischlinger H 2009. Der achte Archaeopteryx – das Daitinger Exemplar. Archaeopteryx. 27:1–20.
Wellnhofer P 2009. Archaeopteryx—the Icon of Evolution. München: Friedrich Pfeil.

7 thoughts on “The Daiting specimen is not Archaeopteryx

  1. hi pterosaurheresies im working on a flapping scale model of archaeopteryx, if you have time can you advise me some things about its flight style?

      • thank you davidpeters, im only a noob of palaeontology, solnhofer birds are a help already. do you think archaeopteryx was capable of climbing flight despite its shorter pinion feathers ? birds sometimes collapse their outmost pinion feathers anyway during flight and are still capable. for technical reason i might need to make the model 20% bigger than the specimens found.

        other than that i have already built a tapejara ornithopter and am open for suggestions which other flapping species could be interesting to make as a flying model.

      • Make sure I know when you post so I can promote your progress here.
        re: climbing flight… everything comes in small gradients, whether in phylogeny or ontogeny. Choose your models well.

      • hello david, FYI an archaeopteryx model is finished see this video: https://youtu.be/XlMkfBROeEg soon i will improve its climbing ability and make more tests and also glide more. i try to make lifelike models, but aim for good flight characteristics too. this model is slow flying, but its possible to build differently and fly more speedy. i think archaeopteryx flight ability may not be the optimal compared to modern birds, but also somewhat efficient, and very stable.

        at the moment i am working on an aurorazhdarcho.

      • thank you , i chose forest because its likely this bird lived among trees, but to pilot from afar is a bit of an obstacle course. if you have suggestions for improvement and other interesting modelling please let me know.

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