What’s inside this rock?

Paleontologists in the Department of Organismal Biology and Anatomy at the University of Chicago are increasingly using high-tech imaging techniques to study ancient fossils. In 2014, a CT scanner was installed in the basement of Culver Hall on the Hyde Park campus, and now researchers use it to see inside fossilized rock to create 3D images of delicate specimens that would otherwise be inaccessible or incomplete.

BY MATT WOOD

Neander uses powerful imaging software to assemble the scanned images and create detailed 3D models of intricate bone structures, like this Docofossor jaw. Then, researchers can enlarge, rotate and reassemble individual bones to understand body mechanics and function.

This slab of rock holds Docofossor, a 160-million-year-old early mammaliaform from the Jurassic period discovered in China. First described by Zhe-Xi Luo, PhD, Professor of Organismal Biology and Anatomy, this tiny mole-like creature was just a few inches long. Removing it from the rock would destroy the specimen.

Researchers use the CT scanner to see inside the rock without harming the fossils. April Neander (above, middle photo), a research specialist and scientific illustrator in Luo’s lab, prepares the specimen, and the machine rotates it while taking hundreds of images from every angle.

A complete sketch of the skeleton is made using the scanned images by combining intact (shaded) elements with those broken or impression-created (outlined). Missing, hence conjectural, elements are shown by dashed outline. Neander uses this detailed size and proportion to create illustrations of what Docofossor looked like in real life.

The Docofossor jawbone, reproduced at a much larger scale than the original specimen, allows researchers to examine detailed structures and understand how individual bones connect and interact with each other.