T-Rex skeleton with gastralia (belly ribs) and other anatomical fixes

thingiverse

I recently got into 3D printing and wanted to try a bigger project to learn some new skills. I thought the MakerBot T-Rex skeleton and all of the remixes were great but there were some anatomical details that weren't quite right that bothered me. In particular, the model lacks gastralia (belly ribs) and the arms were facing down rather than pronated (with the palms facing together). There were also a few issues with the pose that were a little odd. I used the original model and several remixes to try to fix some of these issues. This is still a work in progress. --For the most part, I printed the original MakerBot pieces but also included fixes for the ribs, h-clips, and tail from the "fixed" model by icefox1983. I was planning on trying to modify the arms for the pronated hand position but instead found the model by stargatedalek had already mostly done this (I made a few additional modifications in post-processing). For the mount position, I wasn't satisfied with the way the legs hang in the original model. To change this a bit I printed the original femur and tibia/fibula pieces but printed the metatarsals/feet from the "Leo Burton" mount by lordlilapause. With a few additional post-processing modifications I got what I was looking for. --I didn't find any existing models of gastralia on Thingiverse or anywhere else though there are several people who have posted "makes" of various models that include them. There is a fair bit of variability in how the gastralia are positioned and how they interface with the rest of the skeleton on existing full-size mounts and reconstructions in the literature. I was mostly inspired here by the recent remount of "Sue" at the [Field Museum](https://www.fieldmuseum.org/blog/fresh-science-makeover-sue) and the "Victoria" specimen that I saw earlier in the year at the Arizona Science Center (shown in the picture above). In both of those mounts (though there is some variation) the gastralia fall just below the scapulae and are "floating" in line with the pubis but not quite touching. In both the 3rd or 4th gastralium is nearly touching the 4th or 5th rib on each side. --I'm a novice modeler so I certainly couldn't make this from scratch. I searched Sketchfab and found a number of T-Rex models with varying quality and resolution that included gastralia. I eventually settled on the [Smithsonian "fight scene" T-Rex model](https://sketchfab.com/3d-models/tyrannosaurus-rex-triceratops-smithsoniandpo-e9fa58a7f25645db99b9519073c88b40) because it was a high quality CC model that was downloadable and was also modeled such that the gastralia were connected to each other rather than free floating. I took this model into MeshMixer and removed everything but the gastralia. The model was non-manifold so I fixed that using the Edit tools and then rescaled it to the original T-Rex model (so that the bones would roughly span the distance from the pubis to the front of the scapulae when including the piece that extends of the back of the gastralia). --The gastralia are pretty delicate so I printed this slowly using both a raft and supports. I was worried about being able to get these delicate parts off the supports but actually had fairly little trouble. The raft helped considerably as I was able to hold and bend it to gently let the part separate from the supports. --I connected this to the printed T-Rex model using superglue with a fine line applicator. I glued the thin piece that extends behind the gastralia to the ridge on the under side of the pubis with about 10-12 mm of overlap. I then glued the 3rd gastralium on each side to the 5th rib on each side. This is over all not an ideal set up. A more robust extension and a mounting hole in the pubis would be better but that is beyond my modeling abilities. --As for the position of the mount, I used the legs from the original model and the "Leo Burton" feet together and heated the legs in hot water to make them flexible. I created a low-back pose that I liked based somewhat on the "lunging" look of the Victoria mount pictured above. I still plan on creating a base from sandstone and drilling a hole for the mount from the pubis to fit. Once I do that and paint the skeleton, I'll post additional pictures. --I've included a modified version of the base from the icefox1983 model with the two original holes filled in a new one placed further over as shown in the picture above.