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August 25, 2005

Texas horned lizard 3D head scan

A 3D color head scan of a Texas horned lizard. The scan was created at the High-Resolution X-ray Computed Tomography Facility at The University of Texas at Austin. [Color key: skin color RED=(distance from bone) GREEN=(distance from center) BLUE=Z]

More about this Image
In this visualization, the external skin and internal skeleton are depicted using a color-mapping scheme that represents the distance from the skin to the bone, giving the reconstruction a polychromatic tie-dyed appearance.

These scans were taken as part of research by Wendy Hodges, a biologist at the University of California, Riverside, who received an NSF postdoctoral fellowship in biological informatics. Hodges is attempting to reconstruct the physical features of the common ancestor of the 13 species of North American horned lizards.

Between 23 and 30 million years ago, the first North American horned lizards branched off from sand lizards, becoming stockier and spinier and evolving their distinctive crowns of horns. A single common ancestor gave rise to the 13 North American species, each developing a unique set of cranial horns and spikes. Researchers are trying to determine what this prehistoric, common ancestor may have looked like and how the horns of these species developed. [Image 8 of 9 related images. (Year of image: 2003)

Credit: Research by Wendy Hodges, Timothy Rowe and Reuben Reyes; X-ray CT scans by High Resolution X-ray CT Facility, Univ. of Texas, Austin, Dept. of Geological Sciences; Specimen courtesy of the Texas Memorial Museum of Science and History; Graphics and 3-D models from Univ. of Texas, Texas Advanced Computing Center, ACES Visualization Lab

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