Researchers have uncovered the fossilized remains of a dinosaur with some internal tissues intact, including what may have been the animal's gut and liver. The well-preserved specimen, described in tomorrow's issue of Nature, is the first dinosaur to be unearthed in Italy and could help researchers address long-standing questions about how dinosaurs are related to living birds and reptiles.
The 113-million-year-old fossil was found in 1993 in the southern Italian province of Benevento in an outcrop called Pietraroia plattenkalk, long known for its exquisite fish fossils. Paleontologists Cristiano Dal Sasso of the Museum of Natural History in Milan and Marco Signore of the University of Naples Federico II speculate that the 50-centimeter-long body, probably that of a hatchling or juvenile meat eater, was washed downriver to a shallow sea, where it was buried under silt and preserved. The team named the fossil Scipionyx samniticus, after Scipione Breislak, the 18th century geologist who first described the outcrop, and the Roman warrior Scipio Africanus, who fought battles in the region around 200 BCE. The researchers describe folds in the abdomen and under the tail that appear to be a gut, and they claim that an iron-rich region between the forelimbs may be the remains of a liver.
"Any time you get a complete skeleton of an animal like this, it's always important, because you just don't get that many," says Jack Horner of Montana State University in Bozeman, who adds that the detail of the internal organs is fantastic. However, he says, it's unclear if the fossil will help resolve any key debates, such as whether the animals were warm- or cold-blooded. Paleontologist Mark Norell of the American Museum of Natural History in New York City agrees: "It's going to take a lot more research to put it in context with dinosaur stories in general."