STL Science Center

STL Science Center

20 July 2016

Skeletal Remains

There are many assertions made from as many angles about the remains of Protoavis from the fossil's head to its toes and tail. Starting at the skull, it is described as complete by Chatterjee, though the known fossil is recognized to be missing much of the rostral aspect forward of the temporal region. Additionally, Chatterjee made many observations of the quadrate and its mobility. Subsequent observations and descriptions by Paul, Chatterjee, Ostrom, and others have not validated the shape, articulation, or mobility of the quadrate within the specimens of Protoavis that have been described. The braincase is similarly marred by disagreement. Disagreements are made with the cervical vertebrae and some of the other post-cranial elements, but none as much as the quill knobs that Chatterjee mentions on the broken ulna of the type specimen. The inclusion of these supposed quill knobs caused an inference of feathering and that is why current illustrations depict Protoavis as being a small feathered dinosaur. Many subsequent descriptions of the same anatomy have concluded that the material, because it is fragmentary, cannot be confidently described as possessing quill knobs and flight feathers. Whether this is truly the case or not we may not know for a very long time, if ever, but the image of a feathered Protoavis is normal whereas a non-feathered Protoavis is not common and may not even exist.

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