The feathered sauceback is a species from Sagan 4 which was originally created by Oviraptor. The original artwork for it was made nearly 15 years ago and didn't have much thought to its internal anatomy; now that the anatomy of saucebacks is better established, I decided to make fanart with new information in mind.
In particular, part of the hip girdle in this line of saucebacks is made from an internalized limb segment; in earlier species, such as the Feathered Sauceback, this was not very refined and the apparent "hip" was placed very far back as a result. The basal "hip" joint was really far more like an elbow or a knee. (in later, longer-necked species, the apparent hip is placed more forward, entirely beneath the sauce rather than behind it, though part of the internalized limb segment still projects backwards to make room for muscle attachment)