A Confusing New Species of Hammerhead Shark Discovered

This new hammerhead species makes me wonder about how similar, or different, humans have evolved over time, and how we may evolve in the future. If differences like those in this new shark are possible, are there, or will there be different species of humans walking around looking identical?

news.discovery.com...

There's good and bad shark news. The good news is that a new, as of yet unnamed, species has been discovered. The bad news is that it looks just like the scalloped hammerhead shark, curtailing efforts to save that endangered species.

The new look-alike hammerhead is identical to its near twin save for a few important differences:

distinctive DNA
20 fewer vertebrae (about 170 versus 190)
a genetic profile suggesting it separated from the scalloped hammerhead 4.5 million years ago
That's an incredibly long period of time, considering how similar the two different sharks look externally.

Adding to the confusion is that the new mysterious species seems to have a large range. It was originally discovered off the eastern U.S. Now a paper in the April issue of Marine Biology mentions it's been found more than 4,300 miles away near the coast of southern Brazil.

The look-alike species may face the same fishery pressures as the real scalloped hammerhead, which is being fished unsustainably for its highly prized fins.

“It’s a classic case of long-standing species misidentification that not only casts further uncertainty on the status of the real scalloped hammerhead but also raises concerns about the population status of this new species,” Mahmood Shivji said in a press release

www.mnn.com...

Now, researchers have found the unnamed shark, a so-called "cryptic" species, swimming in waters off the coast of Brazil, thousands of miles from where the species was initially discovered. The find indicates the cryptic species is widespread, and may be facing similar pressure as its nearly identical cousin.