Archaeopteryx number 11
(Figs. 1, 2) has no museum number and is in private hands, but Foth et al. 2014 published a description in Nature. These authors unfortunately considered this specimen just another Archaeopteryx, but one well supplied with feather impressions. In the large reptile tree (LRT, subset Fig. 3) this Solnhofen bird nests at the base of the node that produced two specimens of Sapeornis, a clade convergent with Euronithes in having a pygostyle. The 11th specimen is complete and articulated, but lacks a large part of the cranium.
Foth et al. 2014 do not mention
the lack of a sternum. Sapeornis likewise lacks a sternum even though more primitive taxa have one.
At first glance
this appears to be an ordinary Archaeopteryx. However, when you put the dividers on the bones you find that it differs in subtle ways from the holotype and is more similar to Sapeornis and its sisters. As I mentioned yesterday, it would be a good thing for all early bird workers to start considering the Solnhofen birds individual genera, not a single genus. It’s just a lazy habit we have to overcome.
Foth C, Tischlinger H and Rauhut OWM 2014. New specimen of Archaeopteryx provides insights into the evolution.of pennaceous feathers. Nature 511:79–83.DOI: 10.1038/nature13467