Computer animation and 3D printing have created a demand for high quality 3D models and to meet that demand a whole new business has sprung up: Online 3D model libraries.
Turbosquid is probably the largest professional 3D model source online and there are scores of libraries that provide both free and or commercial models such as WireCASE, 3DXtras, and 3D Model Sharing. One of the newest free 3D model libraries comes from an unusual source: The Smithsonian Institution.
3D Model of Amelia Earhart's flight suit shown in the Smithsonian X 3D viewer
The currently available models include fossils, cultural artifacts, furniture, animals, and scientific models. Among my favorites are the life masks of Lincoln, the Wright Flyer, and the Eulaema Bee (a genus of large-bodied euglossine bees that occur primarily in the Neotropics in case you were wondering).
Laser scanning a whale fossil
Some of the models were created from CT scans while others used photogrammetry or high resolution laser scans and they can all be downloaded as ASCII point cloud files, OBJ files, or 3D printer-ready STL files. The Smithsonian X 3D site is masterpiece not only for its content but also for its impressive engineering.
The great thing about the library is that at any given time the Smithsonian only has about 1 percent of its collection on display so given enough time and money artifacts that have never been seen will be available to everyone and, if you so desire, you'll be able to print a 3D model of your own.