Hero shrews have strong, interlocking spines unlike any other animal, study says

The hero shrew's spine interlocks together to be strong enough to withstand compressive force.

(CNN)Hero shrews may be small mammals that look like rodents, but they're strong, mighty and live up to their name on the inside. Their interlocking spine is unlike anything researchers have ever seen in another mammal.

Exactly why these shrews have such sturdy tricked-out spines is a puzzle researchers are eager to solve.
"Hero shrews have crazy-looking spines -- their vertebrae are squished flat like a pancake, and they have a bunch of extra places where they touch the vertebrae next to them. It makes a really long stiff column along their back, and there aren't good field reports as to what this structure might be useful for," said Stephanie Smith, lead study author and a postdoctoral researcher at the Field Museum and the University of Chicago. "So we wanted to look at those vertebrae and figure out how they might be using them."
    Native to the Congo Basin of Central Africa, these little gray mammals stay out of sight by snuffling through leaves and fallen material on the ground.
      They were first discovered and classified by researchers in 1910, although they were known to the Mangbetu people of the Congo Basin long before then.
        A hero shrew is held by a researcher. They're larger in size than most shrews, more comparable in size to rats than mice.
        The early research about hero shrews included a potentially apocryphal story where the Mangbetu people showed the American and European scientists that a grown man could stand on a hero shrew without harming it. The shrew would pop up and scurry away afterward.
        "We don't know how accurate these stories are, and we'll likely never know," Smith told CNN.
          But Smith, who has always been interested in studying small mammals, wanted to investigate their strange spines. And shrews are particularly misunderstood, often mistaken for mice even though they're more like hedgehogs and moles.
          "Shrews are really interesting ecologically, and they're so small they have almost secret powers," she said. "They're incredibly diverse, and I think they're beautiful. They're dope as hell."
          The intricate interlocking mechanism of the hero shrew spine can be seen here in detail.
          Only two species of hero shrew, including the Thor hero shrew announced in 2013, are known. They're small and live in an area of political unrest, which makes them difficult to study. So Smith and her fellow researcher Kenneth Angielczyk, a curator of paleontology at the Field Museum, turned to museum specimens there.
          "We have specimens of them at the museum, but we can't see them in action. It's almost like studying an animal in the fossil record, where we have specimens that tell us about their anatomy, but we can't bring a live specimen into the lab and observe it," Angielczyk, senior author on the paper, said in a statement.
          And without seeing them in action, it's difficult to know why these shrews might need such highly modified spines.
          CT scans of the spines from both known hero shrew species were taken and compared with those of an average shrew.
          Typically, a mammal's spine has different recognizable regions including the neck, the thoracic region where ribs are attached and the lumbar region between the ribs and pelvis.
          In the hero shrew, both the thoracic and lumbar regions have more individual segments. Rather than five or six lumbar vertebrae, hero shrews have between 10 and 12.
          Parts of the spine sticks out like wings, with nodules and tubercles that touch vertebrae in front of and behind them to create an interlocking network along the spine.