Scipionyx

Filozoa

Scipionyx Temporal range: Early Cretaceous, 113 Ma PreЄ Є O S D C P T J K Pg N ↓
Fossil specimen, Museo Civico di Storia Naturale di Milano
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Superorder:	Dinosauria
Order:	Saurischia
Suborder:	Theropoda
Family:	†Compsognathidae
Genus:	†Scipionyx dal Sasso & Signore, 1998
Species:	†S. samniticus
Binomial name
Scipionyx samniticus dal Sasso & Signore, 1998

Scipionyx (pronounced "SHIH-pee-oh-nicks") is a genus of theropod dinosaur from the Early Cretaceous of Italy, around 113 million years ago. There has been only one skeleton discovered, which is notable for the preservation of soft tissue and internal organs. It is the fossil of a juvenile only half a metre (twenty inches) long. Adult size is estimated to be about two metres (6.5 feet).

History of discovery and naming

Skull, Museo Civico di Storia Naturale di Milano

Scipionyx was discovered in the spring of 1981 by Giovanni Todesco, an amateur paleontologist, in the Le Cavere quarry at the edge of the village of Pietraroja, approximately seventy kilometers northeast of Naples. The specimen was preserved in the marine Pietraroja limestone formation or Plattenkalk, well known for unusually well-conserved fossils. Todesco thought the remains belonged to an extinct bird. He prepared the strange discovery in the basement of his house in Verona, removing, without the use of any optical instrument, part of the chalk matrix from the top of the bones and covering them with vinyl glue. He strengthened the stone plate by adding pieces to its rim and on one of these he added a fake tail made from polyester resin as that of the fossil was largely lacking because he had failed to recover it completely. In early 1993 Todesco, who had nicknamed the animal cagnolino, "little doggie", after its toothy jaws, brought the specimen to the attention of paleontologist Giorgio Teruzzi of the Museo Civico di Storia Naturale di Milano, who identified it as the juvenile of a theropod dinosaur and nicknamed it Ambrogio after the patron saint of Milan, Ambrose. Not being a expert in the field of dinosaur studies himself, he called in the help of colleague Father Guiseppe Leonardi. In Italy such finds are by law State property and Todesco was convinced by science reporter Franco Capone to report the discovery to the authorities: on 15 October 1993 Todesco personally delivered the fossil to the Archaeological Directorship at Naples. The specimen was added to the collection of the regional Soprintendenza per i Beni Archeologici di Salerno, Avellino, Benevento e Caserta in Salerno, to which it officially still belongs; on 19 April 2002 it was given its own display at the Museo Archeologico di Benevento.

In 1993 Teruzzi and Leonardi scientifically reported the find, which generated some publicity as it was the very first dinosaur found in Italy. The popular magazine Oggi simultaneously nicknamed the animal Ciro, a typical Neapolitan boy's name, an idea by chief-editor Pino Aprile. In 1995 Marco Signore of the University of Naples Federico II submitted a thesis containing a lengthy description of the fossil, in which he named it "Dromaeodaimon irene". Because the thesis was unpublished this remained an invalid nomen ex dissertatione. Meanwhile in Salerno, Sergio Rampinelli had begun a further preparation of the fossil, during three hundred hours of work removing the fake tail, replacing the vinyl glue with a modern resin preservative and finishing the uncovering of the bones. On this occasion it was discovered that large parts of the soft tissues had been preserved.

In 1998, Ciro because of this made the front cover of Nature, when the type species Scipionyx samnitcus was named and described by Marco Signore and Cristiano dal Sasso. The generic name Scipionyx comes from the Latin name Scipio and the Greek ὄνυξ, onyx, the combination meaning "Scipio's claw". "Scipio" refers to both Scipione Breislak, the 18th century geologist who wrote the first description of the formation in which the fossil was found and to Scipio Africanus, the famous Roman consul fighting Hannibal. The specific name samniticus means "From Samnium", the Latin name of the region around Pietraroja. Several other names had been considered but rejected, such as "Italosaurus", "Italoraptor" and "Microraptor".

The holotype, SBA-SA 163760, dates from the early Albian and consists of an almost complete skeleton of a juvenile individual, lacking only the end of the tail, the lower legs and the claw of the right second finger. Extensive soft tissues have been preserved but no parts of the skin or any integument such as scales or feathers.

In view of the exceptional importance of the find, between December 2005 and October 2008 the fossil was intensively studied in Milan resulting in a monograph by dal Sasso and Simone Maganuco published in 2011, containing the most extensive description of a single dinosaur species ever.

Phylogeny

Size of the juvenile specimen compared with a human

Scipionyx was by the describers assigned to the Coelurosauria, a group of theropods. Because the only remains recovered belong to that of a juvenile, it has proven difficult to assign this dinosaur to a more specific group. Part of the 2011 monograph was a cladistic analysis which indicated that Scipionyx was a basal member of the Compsognathidae and the sister species of Orkoraptor.

Paleobiology

Scipionyx is considered one of the most important fossil vertebrates ever discovered, after a long and painstaking "autopsy" revealed the unique fossilisation of portions of its internal organs. Parts of the windpipe, intestines, liver, blood vessels, cartilage, horn sheaths, tendons and muscles were fossilised in the fine limestone. The specimen's liver was preserved in the form of a red heamatite halo retaining the shape it had when the animal was alive. The find has great importance because the relative positions of internal organs of dinosaurs could only be guessed at before this discovery. The overall length of the intestines — shorter than what was expected — indicates Scipionyx could process food very efficiently. Some scientists (Ruben, 1999) have also suggested Scipionyx had a respiratory system different from birds, and more similar to crocodiles, based on analysis of pictures of the fossil which seemed to indicate the presence of a diaphragm, which has been used as an argument against the idea that birds are coelurosaurs. John Ruben's research has, however, been confronted by criticism from other scientists, who claim the study to be flawed. The 2011 study concluded that the presumed diaphragm was an illusion.

It is believed Scipionyx lived in a region filled with shallow lagoons. These bodies of water were oxygen deficient, leading to the well-preserved Scipionyx specimen, much like the fine fossil preservation seen in Germany's Archaeopteryx.

External links

• Ciro, the italian dinosaur from Benevento (Sannio)
• "Baby dinosaur from Italy with guts preserved"
• File: Marco Signore and Cristiano dal Sasso showing up the fossil slab of Scipionyx.
• Skeletal diagram of Scipionyx.
• [1].