Wellnhoferia (the Solnhofen specimen of Archaeopteryx)

Updated Novermber 6, 2015 with a new reconstruction. M. Mortimer provided a necessary critique (see comments). I rushed this online yesterday without tracing gastralia, I thought the scapulae extended further beneath the skull, I misinterpreted several pectoral elements and the humeri. A second look brought these in closer accord with sister taxa. 

Earlier we looked at three other Archaeopteryx specimens and noted that they nested at the bases of distinct clades, the Enantiornithes and the Euornithes. Here we’ll add the Solnhofen specimen of Archaeopteryx (aka Wellnhoferia, Elzanowski 2001, Fig. 1) and a few other taxa to the large reptile tree (601 taxa) to see where they nest.

Figure 1. Wellnhoferia grandis added to the large reptile tree nests at the base of all extant birds, Euornithes, and their extinct relatives, distinct from three other Archaeopteryx specimens. The skull is poorly preserved but these parts, if valid, are preserved in impressions, No sternum or clavicles have been found. Rather the gastralia extend to the coracoids here.

Figure 1. Wellnhoferia grandis added to the large reptile tree nests at the base of all extant birds, Euornithes, and their extinct relatives, distinct from three other Archaeopteryx specimens. The skull is poorly preserved but these parts, if valid, are preserved in impressions, No sternum or clavicles have been found. Rather the gastralia extend to the coracoids here.

Distinct from the other Archaeopteryx specimens,
Wellnhoferia has a shorter tail, a precursor structure to the very short tails of extant birds. This specimen (BSP 1999) nests at the base of the clade that includes Confuciusornis to extant birds (Fig. 2).

Figure 2. Theropod dinosaur subset of the large reptile tree showing the nesting of four Archaeopteryx specimens at or near the bases of several basal bird clades, including the Enantiornithes, the Scansoriopterygidae and the Euornithes.

Figure 2. Theropod dinosaur subset of the large reptile tree showing the nesting of four Archaeopteryx specimens at or near the bases of several basal bird clades, including the Enantiornithes, the Scansoriopterygidae and the Euornithes.

The Scansoriopterygidae
nesting as basal birds and other notes and issues raised here (Fig. 2) will be considered in later blogs.

Figure 3 Reconstruction of the pes of the Wellnhoferia. A tiny p4.3 is visible. Also see Figure 3a for a closeup. This matches the tiny p4.3 in Confuciusornis.

Figure 3 Reconstruction of the pes of the Wellnhoferia. A tiny p4.3 is visible. Also see Figure 3a for a closeup.

Unfortunately
Elzaznowski 2001 missed one pedal phalanx from his reconstruction (Fig. 3). The DGS method helped to recover it.

Figure 3a. Closeup of pedal 4.3 in Wellnhoferia.

Figure 3a. Closeup of pedal 4.3 in Wellnhoferia. Yes, it’s an odd displacement. The smallest pedal digit 4 in Confuciusornis is also p4.3.

A while back
I wondered if the the several specimens assigned to Archaeopteryx were inappropriately lumped based only on the earlier observation that Solnhofen pterosaurs were likewise inappropriately lumped. This has proven to be true. For all the many genera and species discovered from the Solnhofen lagoons, there is more than one basal bird present. Those who have reconstructed the several specimens have not added them to phylogenetic analyses. Those who do phylogenetic analyses have not added several Archaeopteryx specimen to their studies. This is remedied, to a certain extent, here.

I once thought I could add nothing to basal bird studies
since so many workers have published on them. Once again, I am proven wrong. The differences between the specimens are shown to be phylogenetic, not ontogenetic.

Figure 1. The six tested Solnhofen birds currently named Archaeopteryx, Jurapteryx and Wellnhoferia.

Figure 5. The six tested Solnhofen birds currently named Archaeopteryx, Jurapteryx and Wellnhoferia.

Over the next few days
I will portray a few of these basal birds, perhaps with some new insight, as I did earlier with Yi qi, the inappropriately identified dragon wing bird.

References
Elzanowski A 2001. A new genus and species for the largest specimen of Archaeopteryx. Acta Palaeontologica Polonica 46(4):519-532.

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One thought on “Wellnhoferia (the Solnhofen specimen of Archaeopteryx)

  1. Checking this out since you emailed me with that Xiaotingia question. You don’t have Wellnhofer’s (1992) long description of the specimen, and have clearly misinterpreted the photos in Elzanowski’s paper. Frankly, as someone who deals with theropods daily, your reconstructions are highly unrealistic. I don’t know where to begin. That skull resembles no theropod. The specimen has 4 premaxillary teeth (8 is unheard of in theropods- the max is 7 in spinosaurids and Pelecanimimus) like every other long-tailed maniraptoran. Most of the skull’s made up, since only the snout and a couple braincase fragments are preserved. Ditto for all but the first few cervicals and last couple dorsals. No Archaeopteryx has an ossified sternum, the coracoid’s much shorter, the tail doesn’t end where you stop it (the last preserved vertebra is broken), and yes it actually has only four phalanges on pedal digit IV. That’s found in other basal paravian specimens too (the Didactylornis specimen of Sapeornis). You’re dealing with perhaps the most scrutinized fossil taxon ever here, you know. Or your London recon, which has 16 short caudals before they elongate. Nothing around that area of the tree has so many. And no theropod has dorsal ribs connected to gastralia via some third segment. The first couple to several dorsal ribs connect via sternal ribs to the sternum, while gastralia don’t connect to either. You just don’t know theropod anatomy, so your attempts at reconstruction don’t match reality.

    Reference- Wellnhofer, 1992. A new specimen of Archaeopteryx from the Solnhofen limestone. Los Angeles County Museum of Natural History, Science Series. 36, 3-23.

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