In equatorial Africa is a small shrew that can bear the weight of an adult human for minutes at a time, and then walk away unharmed. This animal, the armored shrew, has become known as the hero shrew for its amazing strength. But researchers have been puzzled as to why the creature evolved that way — built with an incredibly strong spine that no other animal had been found to have. Now a research team led from the Field Museum in Chicago has discovered a new species capable of similar feats of strength, which they're calling Thor's hero shrew. The new animal appears to sit between the armored shrew and common shrews, and it's helping to reveal the mystery behind the both creatures' impressive spines.

Four times stronger than the average spine

Like the armored shrew, Thor's hero shrew's strength comes from an unlikely series of interlocking vertebrae, which reportedly create a spine that's four times stronger than those found in most animals. The researchers spoke with locals to learn more about the previously undocumented species, and they found that the new shrew tended to show up near palm trees. The team now speculates that the Thor's hero shrew uses its strength to break off dead palm leaves and access energy-rich beetle larvae that's hidden within the tree trunk. The creature's robust spine may also allow it to push aside heavy rocks and logs that prey such as earthworms hide beneath. Altogether, the researchers suspect that this constant access to high quality food sources is likely to have driven the evolution of both shrews.

It took the researchers eight days to catch a single of the new shrews for examination. The team set out over 1,000 traps in a forest near the Tshuapa River in the Democratic Republic of the Congo, checking them each day after they'd sat overnight. According to Scientific American, the new shrew appears so similar to the armored shrew that it required examination of the animal's skull and DNA to tell it apart. The team's research was published Wednesday in Biology Letters — they suggest that more studies will need to be done to verify their ideas about the evolution of both shrews, but even if changes need to be made, the team believes that the new species should help other researchers to fill in the evolutionary gap.