One part of the skeleton reconstruction I found challenging was the
pelvis. The drawings of Madsen (1976) are complete but not easy to
follow. Each sacral vertebrae and rib is shown separately from front,
back and side. However, how they all articulate is not shown and I struggled to
understand how all the bones joined up. So I fitted them together virtually on the computer screen.
Each of Madsen's lateral drawings was scanned, rotated, cleaned, and scaled into separate layers in PhotoShop. I could then experiment with how to fit them together and also hide/show different bones. The sacral ribs are hard to see, so these were recolored for contrast.
The following images are from the manuscript of Gilmore, Charles W. (1920). "Osteology of the carnivorous dinosauria in the United States National Museum, with special reference to the genera Antrodemus (Allosaurus) and Ceratosaurus". Bulletin of the United States National Museum 110: 1–159. The drawings in Gilmore's publications are always superb! Click each image to view full size.