Scipionyx samniticus Archives - The Big Dinosaur Podcast

Episode 74 is all about Scipionyx, a compsognathid that lived in Italy and has the nickname “Ciro.”

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In this episode, we discuss:

Compsognathid that lived in the early Cretaceous in Italy
Named in 1998
Famous because paleontologists found lots of soft tissue and internal organs, including muscles and intestines

First dinosaur discovered in Italy
Only one fossil found of Scipionyx, and it was discovered in 1981 by amateur paleontologist Giovanni Todesco (he thought it was an extinct bird)
Todesco prepared the fossil in his basement, using vinyl glue and adding a fake tail

Todesco nicknamed the fossil “little doggie” and in 1993 Giorgio Teruzzi from the Museo Civico di Storia Naturale di Milano learned about the fossil and said it was a juvenile theropod. He nicknamed it Ambrogio, after Ambrose, the patron saint of Milan
Teruzzi also enlisted the help of his colleague Father Giuseppe Leonardi
In Italy the fossil find belongs to the government, and Todesco ended up giving the fossil to the Archaeological Directorship at Naples in October 1993

In 1993 Teruzi and Leonardi reported the fossil scientifically, and the magazine Oggi nicknamed it Ciro “a typical Neapolitan boy’s name”
Marco Signore from the University of Naples Federico wrote a thesis in 1995 naming the fossil Dromaeodaimon irene, but the paper was unpublished so the name was not used
Sergio Rampinelli worked on the fossil for 300 hours to restore it (replace the glue and remove the fake tail); that’s when he found all the soft tissue
Marco Signore and Cristiano dal Sasso named and described Ciro as Scipionyx samniticus, and it was featured on the front cover of Nature in 1998

The first paper Cristiano dal Sasso and Marco Signore wrote was called “Exceptional soft-tissue preservation in a theropod dinosaur from Italy,” published in Nature in February 1998
The name Scipio is for Scipione Breislak, a geologist from the 18th century who first described the formation (Pietraroia Plattenkalk) where Ciro was found, and for Cornelius Scipio (nickname Africanus), a famous Roman consul who fought in the Mediterranean area
The species name means “From Samnium” the “ancient name of the region including the Benevento Province”

Other potential names were Italosaurus, Italoraptor and Microraptor
The holotype is nearly complete, and includes the lower legs and a claw on the right second finger
Cristiano dal Sassa and Marco Signore further studied the fossil in 2005-2008 and wrote an extensive monograph in 2011 about Scipionyx

The specimen found is of a very young dinosaur, maybe only 3 days old
There’s a large empty space between the back of its intestines and the pubic shafts. It may have had a yolk sac from hatching that it would have used to help give it more nutrients during the first couple weeks after hatching
Size of the yolk sac means it was probably 3 days old, maybe even 1 week old

Juvenile theropod dinosaur discoveries are scarce
Even though it was so young it could walk
dal Sassa and Signore estimated it to be 18 in (~46 cm) long (including the missing tail), which is only a little smaller than Allosaurus hatchlings, but because it’s Compsognathidae, an adult Scipionyx probably only grew to 93 inc (237 cm) long (same size as Sinocalliopteryx, the largest known compsognathid)

They found 8 unique traits in Scipionyx, including 5 teeth in the premaxilla on each side and a wrist with only two bones
Straight, long lower jaw with 10 teeth on each side; the jaw bone is low
Had 7 teeth in the maxilla on each side; total of 44 teeth in all

Probably had primitive feathers (based on relatives)
No skin or evidence of feathers have been found
Lots of soft tissues preserved, including some blood vessels, cartilage, connective tissue, bone tissue, muscle tissue, and parts of the respiratory and digestive systems

Original bone tissue isn’t there, but calcium phosphate mineralization preserved the bone cell structure
Only a piece of the trachea (respiratory system) is preserved, a very thin piece about 1 mm wide
Also can see horn sheaths of hand claws

Liver was also preserved (in the right shape), which helps show the relative positions of internal organs
They saw a large, reddish area and concluded it was the liver
In 1999 a study by Ruben and others found that Scipionyx had a respiratory system similar to a crocodile’s because of its large liver. But dal Sasso and Maganuco’s study in 2011 found that the liver may have been distorted in fossilization and just looks bigger, and also some birds have large livers, so it probably was more bird-like than crocodile-like

Also found some semi-digested lizards and fish in the gut; maybe parents fed it to the baby?
Parents probably fed the baby (unlikely to catch the lizards or fish itself at 3 days old or bite into pieces and swallow by itself)
No stomach acid on the bones in the stomach, so the meal was less than one day old

An “opportunistic generalist” eater (ate fast lizards and fish that washed ashore)
Lived in an area with shallow lagoons
Lived in an area with lots of small islands, and was probably one of the bigger animals in its habitat

Some compsognathids care considered to be basal coelurosaurs, others as part of Maniraptora
Fun fact: There are many types of fossilized eggs, but according to Konstantin Mikhailov and others in “Parataxonomy of Fossil Egg Remains” published by Taylor and Francis, there are 6 basic eggshell types:
- Testurdoid (Chelonia – the green sea turtle)
- Geckoid (Gekkota – mostly gekkos)
- Crocodiloid (Crocodilia)
- Dinosauroid-spherulitic (Sauropoda and Ornithopoda)
- Dinosauroid-prismatic (protoceratopsids and hypsilophodontids)
- Ornithoid (theropoda and modern birds)

I Know Dino Podcast Show Notes: Scipionyx (Episode 74)