TIFF 2017 Benedict Cumberbatch aka Dr Strange

A CT scan of a shark that recently surfaced on Reddit is making waves, partially because of the shark’s wonderfully bemused expression. But while his wide eyes and gaping mouth probably remind you of Benedict Cumberbatch, the team of researchers behind this photo see something a bit different. They see a project that they hope will have profound effects on how we understand the evolution of fish species.

The hammerhead’s headshot is one of 6,000 scans of fish skeletons currently housed in the University of Washington’s Comparative Biomechanics Department, although only 2,600 have been put up on their website. A team of fish enthusiasts from a diversity of scientific backgrounds are trying to scan the skeletons of every fish on the planet and they’re making big strides, as the lead of the project Adam Summers, Ph.D., tells Inverse.

“This has been incredibly popular. We’ve had hundreds of people come through the lab and get good data. I expected it would be totally awesome, but my whole career, after twenty years of scanning things, I wished that people would share these things.”

The scan of this hammerhead illustrates the project’s popularity. Now part of Summer’s larger collection, it was originally done by Kyle Mara, Ph.D., a biologist now at the University of Southern Indiana, and other researchers as part of a different study intended to illuminate the forces that drove the evolution of the shark’s hammer, called a cephalofoil. These results were published in The Journal of Morphology in 2015.

hammerhead sharks
The divergence of cephalofoils in different species of  hammerhead sharks 

“It’s a scan I really like,” Summers says. “I see all sorts of things in there. I see these broad lateral supports for the eyes. I see really wide mounts. The neat thing there is that across a bunch of hammer heads, that one has very large body size and still a respectably wide head, so its head is a platform for sensory systems.”

Mara’s paper suggests that perhaps the driving force behind the changes in the cephalofoil was an evolutionary tweaking of unique shark sensory systems — like their ability to pick up on electromagnetic impulses through tiny sensors that, in hammerheads, tend to cluster around the bottom edges of their wide head. However, the details of this evolutionary story are still the subject of ongoing inquiry.

It’s problems like these that Summer’s scanning program hopes to solve by providing open access images for people who are looking to answer big questions.

“Tomorrow morning if you woke up and said, ‘Oh my gosh, I just had the greatest idea about hammerhead skulls,’ you would not have to scan them yourself or raise 30,000 dollars to do it,” Summer says. “You can just go and grab it.”