Norton Publishers 
 
 When Charles Darwin visited South America on HMS Beagle in the 1830s, he discovered fossils of several hefty mammals that defied classification, such as Macrauchenia, which looked like a humpless camel with a long snout; or Toxodon, with a rhino’s body, hippo’s head and rodent-like teeth — which he described as “perhaps one of the strangest animals ever discovered”. By comparing these molecules to those of modern mammals, the team concluded 
 
 that the two ancient beasts are most closely related to perissodactyls—odd-toed hoofed mammals like rhinos, tapirs, and horses. The confusion over their ancestry is partly due to a fragmentary fossil record, but also because researchers have had no luck isolating DNA from South American ungulate fossils; the molecule degrades quickly in the continent’s warm climate. The protein survives around ten times as long as DNA and is a major structural component of bone. (This bounty also means that contamination of ancient samples by collagen from scientists or other creatures isn’t really a problem.) So Ian Barnes, a molecular evolutionary biologist at the Natural History Museum in London, teamed up with bioarchaeologist Matthew Collins at the University of York, UK, and an international team of researchers to try a different tactic: extracting collagen. The team first built a collagen family tree, which laid out the collagen sequences of different mammals on the basis of their familial relationships. South American ungulates were recently suggested — on the basis of their fossils — to be part of the group Afrotheria, along with elephants and manatees1. In 2007, US researchers claimed to have sequenced collagen fragments from a 68-million-year-old dinosaur fossil4, but the result has proved controversial. Part of a group of more than 250 mammals known as the South American ungulates, the creatures lived on the continent for around 60 million years before disappearing around 12,000 years ago.
– A humpless, snouted camel? Check. A rhino with the teeth of a rodent and head of a hippo? No problem, scientists say, after apparently figuring out, finally, where these mystery creatures sit on the mammalian family tree, Nature reports. Charles Darwin discovered fossils of these ancient creatures while visiting South America in the 1830s, but failed to classify them (and called the rhino-like animal "perhaps one of the strangest" ever discovered). Scientists continued to have no luck placing the mammals—which flourished for 60 million years and vanished around 10,000BC—in part because the fossils' DNA degraded too fast in the warm climate of South America. Now two British researchers have taken a different route, by extracting collagen protein from the fossils. "Compared to DNA, there’s absolutely tons of it," says one of the scientists, Ian Barnes. First they created a "collagen family tree," using the protein to figure out other animals' familial relationships. Then they sequenced collagen from specimens of the rhino-ish Toxodon and camel-like Macrauchenia sitting in Argentinian museums. Turns out the hoofed mammals that baffled Darwin are part of the Perissodactyla group, which includes rhinos, tapirs, and horses, the researchers say. So why care, unless you're a Darwin enthusiast? Because this method can be used to analyze other creatures going back millions of years—much further than DNA. "DNA sequencing is changing, but protein sequencing is undergoing a similar revolution in the sensitivity of the instruments," Barnes tells National Geographic. "Who's to say what we can do?" (A fascist warrior-poet's DNA was recently reconstructed with help from a "love hanky.")