Scipionyx, meaning “Scipio’s claw,” and named after Scipione Breislak, is a genus of theropod dinosaur from the Early Cretaceous Period of what is now Italy (113 million years ago). It was discovered in 1981 by amateur paleontologist Giovanni Todesco near Pietraroja, Italy, about 50 miles from Naples. Fossils were preserved in the Pietraroja limestone formation, well known for unusually well-preserved fossils.
Todesco thought the fossilized remains were that of a bird. Unaware of the importance of his findings, he kept the fossil in the basement of his house for 11 years. In 1992, he met two paleontologists, Cristiano dal Sasso of the Natural History Museum of Milan and Marco Signore of the University of Naples Federico II, who identified his find as the first Italian dinosaur. Six years later, in 1998, Scipionyx made the front cover of Nature.
Todesco’s find, the only known specimen, is that of a juvenile only a few inches long. In adulthood, its size would have been about 6 feet long. Scipione Breislak, who the dinosaur was named after, made the first written descriptions of the formation in which the fossil was found. The specific name, samniticus, means “From the Samnium,” the Latin name of the region around Pietraroja. The specimen has also been given the nickname “Skippy,” or “Doggy.”
Scipionyx is classified as a coelurosaurian theropod. Because the only remains of Scipionyx known are that of a juvenile, it has not been possible to assign it to a more specific group. Characteristics of a Coelurosaur included a sacrum (series of vertebrae attached to the hips) longer than in other dinosaurs, a tail stiffened at the tip, and a bowed ulna (lower arm bone). Also, in Coelurosaurs, the tibia (lower leg bone) is longer than the femur (upper leg bone).
Scipionyx is considered one of the most important fossil vertebrates ever discovered. A painstakingly long “autopsy” of the specimen revealed the unique fossilization of portions of its internal organs. Parts of its windpipe, intestines, liver and muscles were preserved in the fine limestone. The specimen’s liver was so well preserved that it is thought that it retained both the shape and color it had when the animal was alive.
The findings of the autopsy have significant implications because the relative positions of internal organs of dinosaurs could only be guessed before this discovery. The overall length of the intestines were much shorter than what was generally expected, indicating that Scipionyx could process food very efficiently. Some scientists, including John Ruben, have also suggested Scipionyx had a respiratory system different from birds, and more similar to crocodiles, based on fossil analysis. The idea has been met with criticism from many experts, who consider research done by Ruben to be flawed.
Scipionyx may have lived in a region with shallow lagoons. These bodies of water were oxygen deficient, leading to the well-preserved specimen, much like the fine fossil preservation seen in Germany’s Archaeopteryx.