Banner image: Computerized tomography (CT) scan of a Mexican spiny-tailed iguana. (Credit: UCM 11735 Ctenosaura pectinata)
The Mexican spiny-tailed iguana is ready for its close up.
This iguana (Ctenosaura pectinata), which can come in colors from green to gray and orange, lives in scrubby habitats on the western coast of Mexico. And it’s a behemoth: The animal has a line of spikey growths that run down its back, and it can reach more than 3-feet in length.
Now, thanks to a new project at the CU Museum of Natural History, you can also see what the iguana’s insides look like in impressive detail.
Over three years, a team of museum staff and students at CU Boulder will collect high-tech 2D and 3D images of roughly 1,100 species of reptiles and amphibians housed in the museum’s collections. Those images will include CT scans of the specimens’ internal anatomies—in such detail that you can sometimes make out the food sitting in their stomachs.
“It provides us with a complete dataset where researchers can study the internal anatomy of these animals without having to destroy the preserved specimen to visualize its skeleton or organs,” said Emily Braker, vertebrate collections manager at the museum.
The effort, a partnership with the University of California Berkeley and University of Florida, is called oMeso and is funded by the U.S. National Science Foundation. The images, which focus on animals from Mesoamerica, will be publicly available through the museum’s collections database and in an exhibit in English and Spanish coming in 2022.
For Braker, the project is an opportunity to take a new look at these often-unappreciated animals—many of which have begun to disappear across the globe because of poaching, habitat loss, disease and other threats.
“This project will highlight the uniqueness of this region of the planet,” Braker said. “But I also hope that it will engage visitors around new museum technologies and how we use collections to facilitate research and conservation.”
The effort, which launched this fall, will home in on a particularly important part of the world for reptiles and amphibians, or what zoologists like Braker call “herps.” (Herpetology is the study of reptiles and amphibians). Mexico and nearby areas, she said, boast some of the highest diversities in the world of these scaly, occasionally slimy organisms.
Here, you can find the Mexican vine snake (Oxybelis aeneus), a skinny-faced snake that uses its powerful muscles to dangle from tree branches. There are also axolotls (Ambystoma mexicanum), bizarre salamanders that live underwater and breathe with the help of feathery gills.
“We have species from different habitat types like high plains, cloud forests and coastal regions. They really vary in terms of ecology and life mode,” Braker said.
In all, the museum hosts more than 68,000 specimens of herps, almost a third of them from Mexico and nearby areas. Most were collected by zoologists during scientific expeditions in the mid-20th Century.
Researchers from across the globe can request loans of many of these specimens, but they usually have to travel Boulder in person to study the rarest or most endangered organisms in the collection. Which is where oMeso comes in.
Inside and out
Over the following months, Braker and her colleagues will use advanced imaging techniques to snap high-resolution photos of a subset of the museum’s herp collections to capture their external traits. They’ll also use a computed tomography (CT) scanner in the Materials Instrumentation and Multimodal Imaging (MIMIC) facility on campus to visualize what those same herps look like on the inside
While the images are impressive to look at, Braker added that museum collections can also preserve a glimpse at some of the world’s most vulnerable animals—showcasing how the ranges of rare or endangered organisms have shifted and even vanished over time. Some estimates suggest that as many as 200 species of amphibians alone may have already gone extinct around the world since 1980.
“Many conservation specialists would be interested in just seeing images from our collection since a lot of the specimens we’re targeting might be really rare in the wild,” Braker said.
Braker also has her own favorite herp. Her team is collecting images of pygmy salamanders in the genus Thorius from Mexico, some of which are so small that their entire skulls could fit on top of a red pepper flake. Soon, she said, people anywhere in the world will be able to see these tiny creatures in previously-impossible detail.
“They’re so small that it’s hard to even see their limbs with your bare eyes,” Braker said. “So to scan these miniaturized species and then be able to project their skeletons the full width of a computer monitor opens up unprecedented opportunities to investigate the form and function embedded in their anatomy.”