The Berlin Archaeopteryx
(MB.Av.101, A. siemensii, Dames 1897) has been traced (Fig. 1) and added to the Large Reptile Tree where it nests basal to the London specimen and the Enantiornithes, close to the base of the rest of all birds. Thus this fossil is a primitive, plesiomorphic specimen. Earlier we looked at other Archaeopteryx specimens here, here and here.
this unique specimen shows why you should not take and combine elements from several Archaeopteryx specimens to create an ‘ideal’ skull.
has shifted in this specimen, the classic and complete Archaeopteryx (Fig. 2).
makes this specimen very exciting. Soft tissue either obscures the clavicle or creates the illusion of a clavicle. The anterior gastralia extend to the coracoids, but, just as in derived birds, a sternum appears to be developing ventral to the anterior gastralia, perhaps unossified at this stage.
Speaking of Archaeopteryx skulls…
I was not aware of the Alsono et al 2004 paper on the extrication and CT scanning of the London specimen skull until this evening. I have made the necessary changes warranted by the additional data (Fig. 3).
Dames W 1897. Ueber Brustbein, Schulter-und Beckengürtel der Archaeopteryx [About sternum, shoulder and pelvic girdles of Archaeopteryx.]. Sitz.-Ber. Akad. Wiss. Berlin 1897 818-834, 3 figs.