Skippy the dinosaur

Jeff Poling

Italian paleontologists published in the March 26, 1998, edition of the journal Nature the discovery of an extraordinarily well preserved dinosaur.

The fossil was discovered and excavated approximately ten years ago by an amateur paleontologist named Giovanni Todesco. The fossil was found about 30 miles northeast of Naples, Italy, in Benevento province. The fossil was preserved in the Pietraroia limestone formation, a formation well known since the 18th century for its unusually well-preserved fossilized fish. Mr. Todesco thought the fossilized animal was a bird, and therefore nothing out of the ordinary. It was not until after seeing the movie Jurassic Park that he took the fossil to a museum for examination. The scientists realized the fossil was of a non-avian dinosaur, the first ever found in Italy. The find was briefly reported in 1993, but its true importance and uniqueness had not yet been realized.

It turns out that the nine inch long fossil includes major portions of the animal's intestines, colon, liver, muscles, and windpipe. These soft tissues are extremely well preserved, even better than those found on fossils recently discovered in Brazil and China.

Dr. Michael J. Benton, a paleontologist at the University of Bristol, England, said that the position of the dinosaur's liver might be particularly important. "The lungs are not preserved," Dr. Benton said, "but the position of the liver may help define where the lungs were in this animal. The primitive respiratory system of present-day crocodiles differs significantly from that of birds, which have a much more efficient system. This Italian fossil might give an indication of whether the dinosaur's breathing system was closer to that of crocodiles or birds, a question that bears on the controversy over the kinship of dinosaurs." Dr. Benton also stated that the "... animal's gut was shorter than might have been expected, so it probably was able to process food very efficiently."

Although fossilized soft tissue, including internal organs, has been discovered before, none have quite the degree of preservation as this specimen. The part believed to be its fossilized liver is faintly tinted a dark purple, a coloring that may have survived from life. Dr. Benton also reports that the surface texture of the gut is preserved, "... which is lumpy and shiny, almost as you would see it after dissecting a modern animal."

The dinosaur lived approximately 113 Ma ago during the mid-Cretaceous. It lived in an area covered with shallow lagoons that were often oxygen deficient. These lagoons laid down fine limestone deposits resulting in exceptionally fossilized soft tissue of fishes and, as is now known, dinosaurs. These lagoons were similar to those that resulted in the fine Jurassic limestones of Solnhofen, Bavaria, Germany, that produced the dinosaurs Compsognathus and Archaeopteryx.

The animal is identified as a maniraptoriforme theropod of indeterminate family. The difficulty in placement is due to its mix of characteristics. It has some of the features of dromaeosaurs (such as Velociraptor) and some of the features of troodontids. Because none of the animal's teeth had yet been replaced, the scientists concluded that it was a baby only recently hatched. The lack of adult characteristics may be why it appears to have such a mix of features and what may prevent it from ever being placed with absolute certainty.

The fossil was examined and published by Cristiano dal Sasso of the Museo Civico di Storia in Milan, and Marco Signore of the Universita degli Studi di Napoli in Naples. They named the dinosaur Scipionyx samniticus to honor Scipione Breislak, the geologist who wrote the first scientific description of the limestone formation in which the fossil was found, the ancient Roman general Scipio Africanus, and Samnium, the ancient name of the region that includes Benevento province. The fossil is now housed at the Archeological Administration in Salerno.

From: Don Lamson <dlamson@iea.com>

Signore said the dinosaur would have been part of the evolutionary line leading to birds. While it did not fly itself, it had a small V-shaped bone or "furcula" which modern-day birds are equipped with to support their beating wings.

"We're going back to the Benevento region to see if we can find more examples of this dinosaur and perhaps other new species," said Signore. "This is just the beginning."

From: "Thomas R. Holtz, Jr." <th81@umail.umd.edu>

I guess I don't have to sit on this story anymore, since its gone out over the wires, and I was just on Aussie radio live...

The really, really well-preserved Benevento theropod (southern Italy, Albian age) which has been described briefly in the past has been described in a paper in the latest Nature:

Dal Sasso, C. & M. Signore. 1998. Exceptional soft-tissue preservation in a theropod dinosaur from Italy. Nature 392: 383-387.

It is named Scipionyx samniticus, after the discoverer of the Pietraroia Plattenkalk (the formation in which it is preserved) Scipione Breislak (and also for Publius Cornelius Scipio Africanus, the famous Roman general) and after Samnium, the ancient name for this region of Italy.

I would like the opportunity to be the first to publicly call it Skippy the Dinosaur. :-)

It is considered a maniraptoriforme of no certain affinity: looks pretty compsognathid-like, although differs from Compy and Sinosauropteryx in manual features. It's got a furcula (no big surprise). It's a baby (had not gone through the first wave of tooth replacement, HUGE skull size, gigantic hyoids (as long as the forearm), etc.), only 24 cm from tip of premax to caudal 9 (the end of what is preserved).

Mineralized internal features are present, including muscle fibers, and 3D preserved intestines! The small intestine is present in the anterior half of the abdominal cavity, while the colon extends through the pelvic canal and down subparallel to the ischium.

Unfortunately, no external integument is preserved: no sign of skin nor anything (scale, protofeather, hair, loofa, sandpaper, etc.) on it.

So, we've had Rahona, Shuvuuia, and Scipionyx this year so far. Any other new dinosaur genera? Come on, ornithischian and sauropod workers: you're slacking off! :-)

From: Chris Nedin <cnedin@geology.adelaide.edu.au>

Tom Holtz wrote:

Unfortunately, no external integument is preserved: no sign of skin nor anything (scale, protofeather, hair, loofa, sandpaper, etc.) on it.

This is no great surprise. Exceptional preservation such as this depends on a carefully maintained microenvironment in order to precipitate the calcium phosphate and calcium carbonate necessary to preserve soft tissue. Thus only the internal 'soft' tissues will decay rapidly enough to produce enough acid plus dissolved phosphate levels to allow soft tissue mineralization. The outer tissues will loose acidity and phosphate concentration to the external environment and will not preserve soft tissues.

From: "Matthew Troutman" <m_troutman@hotmail.com>

Tom Holtz wrote:

The small intestine is present in the anterior half of the abdominal cavity...

This says that this theropod could not have had a diaphragm. Ruben et al.'s suggestions seem to not apply for this dino.

From: Gautam Majumdar <gautam@majumdar.demon.co.uk>

Ralph Miller III <gbabcock@best.com> wrote

What are the dimensions of the depicted fossil slab? What is the projected length of the animal?

The length given in the article as 23.7 cm from the tip of premaxilla to the last (ninth) preserved caudal vertebra. From the pictures in the Nature with scale bar, the skull appears to be ~5.2 cm long. The ratios given in the article are forelimb/presacral 0.75, skull/presacral 0.48. Average diameter of the intestine is 5.22 mm.