Pro/. 0. C. Marsh — On Jurassic Birds 8f their Allies. 485 



II. — Jurassic Birds and their Allies.^ 



By Professor 0. C. Marsh, F.G.S. ; 



of Yale CoUege, Newhaven, Ct., U.S.A. 



ABOUT twenty years ago, two fossil animals of great interest 

 were found in the lithographic slates of Bavaria. One was 

 the skeleton of Archceopteryx, now in the British Museum, and the 

 other was the Compsognathus preserved in the Eoyal Museum at 

 Munich. A single feather, to which the name ArcJiceopteryx was 

 first applied by Von Meyer, had previously been discovered at the 

 same locality. More recently, another skeleton has been brought to 

 light in the same beds, and is now in the Museum of Berlin. These 

 three specimens of ArcJiceopteryx are the only remains of this genus 

 known, while of Compsognathus the original skeleton is, up to the 

 present time, the only representative. 



When these two animals were first discovered, they were both 

 considered to be reptiles by Wagner, who described Compsognathus, 

 and this view has been held by various authors down to the present 

 time. The best authorities, however, now agree with Owen that 

 Archceopteryx is a bird, and that Compsognathus, as Gegenbaur and 

 Huxley have shown, is a Dinosaurian reptile. 



Having been engaged for several years in the investigation of 

 American Mesozoic birds, it became important for me to study the 

 European forms, and I have recently examined with some care the 

 three known specimens of Archceopteryx. I have also studied in the 

 Continental Museums various fossil reptiles, including Compsognathus, 

 which promised to throw light on the early forms of birds. 



During my investigation of ArcJiceopteryx, I observed several 

 characters of importance not previously determined, and I have 

 thought it might be appropriate to present them here. The more 

 important of these characters are as follows : — 



1. The presence of true teeth, in position, in the skull. 



2. Yertebrse biconcave. 



3. A well-ossified, broad sternum, 



4. Three digits only in the manus, all with claws. 



5. Pelvic bones separate. 



6. The distal end of fibula in front of tibia. 



7. Metatarsals separate, or impex-fectly united. 



These characters, taken in connexion with the free metacarpals, 

 and long tail, previously described, show clearly that we have in 

 Archceopteryx a most remarkable form, which, if a bird, as I believe, 

 is certainly the most reptilian of birds. 



If now we examine these various characters in detail, their 

 importance will be apparent. The teeth actually in position in the 

 skull appear to be in the premaxillary, as they are below or in front 

 of the nasal aperture. The form of the teeth, both crown and root, 

 is very similar to the teeth of Hesperornis. The fact that some 

 teeth are scattered about near the jaw would suggest that they were 

 implanted in a groove. No teeth are known from the lower jaw, 

 but they were probably present. 



1 Read before Section D., British Association, at York, Sept. 2nd, 1881. 



