Watch out, Mighty Mouse: Scientists have found a new species of shrew with incredible strength.
Dubbed Thor’s hero shrew after the brawny god of strength in Norse mythology, Scutisorex thori is one of the most bizarre animals on Earth thanks to its supertough, interlocking spine, according to Bill Stanley, the director of collections and a zoologist at Chicago’s Field Museum, who helped identify the creature.
Found recently in the Democratic Republic of the Congo (DRC), the shrew is only the second hero shrew known to science. The first, S. somereni, was found in the DRC in 1910, baffling scientists with a spine never before seen in any mammal. (See “Largest Elephant Shrew Discovered in Africa.”)
Most mammals, including us, have about five vertebrae at the base of their backbones, with a few bony projections sticking out on each vertebra, explained Stanley. But the first known hero shrew, S. somereni, has 10 to 11 vertebrae with many more bony projections that lock together, giving it unparalleled power in the animal kingdom.
It’s so strong that, according to written accounts of DRC explorers in early 1900s, a man stood on the back of a hero shrew for five minutes, stepped off, and the animal walked away unharmed, Stanley said.
Stanley’s not sure if the story well, holds up—he hasn’t tried it himself—but the anecdote is not surprising considering the hero shrew’s reputation among the local Mangbetu people. The Mangbetu wear parts of the hero shrew as talismans, believing the animal’s resilience renders them invisible to spears and bullets—hence its name, hero shrew.
Why the Strong Back?
When Stanley first dissected the new shrew and found its superstrong spine, he was shocked.
“That’s when the shivers really ran down my back,” he said.
Not only had he found a second species of hero shrew, but the new animal may give some insight into how this odd backbone evolved. (See video: “Venomous ‘Giant Shrew’ Caught on Film.”)
For instance, Thor’s hero shrew has eight vertebrae in its lower back—closer to what a regular shrew would have, but not quite as many as the original species. What’s more, there are fewer bony projections on each side of the vertebrae than on the first hero shrew. So Stanley and team suspect Thor’s hero shrew may be a transitional form in the evolutionary history of hero shrews, suggesting that the spine evolved over a long period time, not relatively rapidly as some had proposed.
In addition, in the July 24 edition of Biology Letters, Stanley and colleagues offer a new theory for why these hero shrews’ have such strong backs—that the extra muscle allows the animal to access food-rich spots not accessible to other animals. (See “Moles, Shrews Can Smell Prey While Underwater, Study Suggests.”)
In the DRC, insects live under the parts of palm trees where leaves have broken off, leaving a hardened base that looks like a scar. It’s possible that shrews may use their powerful backbones to pry the leaf bases from the trunk and get to the tasty grubs underneath. However, Stanley cautioned, no one has seen the shrew actually do this.
In fact, like Superman or Batman, the private life of Thor’s hero shrew is still very much a mystery.
“We’ve barely scratched the surface on these things,” he said.