| The lagoon dwellers The few remains of fossil flora and above all the
plenty of fauna in, allow us to examine better the natural surroundings. According to
Prof. DErasmo the discovery of plant remains meant that there were emerged land
nearby. Several examples of plants belonging to order of Gimnosperme generi
Cicadine e Gingkoine, were found in the lagoon. Besides if there are several kinds of
pollens it means that the emerged lands were nearby.
There are plenty of microfossils such as radiolari,
probably owing to the big amount of silica in the surroundings which gave rise to flint
stripes and nodules. You can find seldom foraminiferi referred to deep-sea
form which got the lagoon after tides or storms.
The same conditions might have given rise to poriferi
spicule (silicosponge) since sponges do not like pond waters. In the block of strata
fish-stones there are not water seaweeds but there are plenty of them on the top of that
block and at its bottom.
As for the macrofossils in the calcareous ittioliti stones
a specimen of echinoderm (that was anasterozoo) was found, it is an
exceptional example of fossilisation so that Pietraroja discovery is surely due to its
quick covering (in the same way) likewise the specimen of European lobsters which were
found in very bad conditions.
As far as
the vertebrates it is established the peculiarity of Pietraroja area,
particularly concerning fishes, amphibians, and reptiles.
In calcareous stones there are more than 20 species of lagoon, fresh,
brackish and open waters, fishes belonging to the superorders of Selaci, Holostei,
Holecostomi and Teleostei. It is worthwhile to mention the wonderful specimen of
Dyplomistus, a typical fresh water animal which got the lagoon when that was linked with
the open sea; the dangerous Coelodus: by its cutter teeth was able to chew up mollusc
shells.
The Belenostomus with sharp teeth, predator of small plankton-eaters
species such as Leptolepsis; Lepidotes, Hemielopis and Notagogus, all of them very kept
showing clearly scales and fishbones. A wonderful specimen of the present salamander
ancestor has been found and, among reptiles, two specimens of crocodiles and the famous
dinosaur puppy commonly named Ciro.
Thanks to the discovery of "Scypionix Samniticus" and to its
perfect condition in fossilisation scholars examined more closely all the park area.
Pietraroja dinosaur was similar to
Velociraptors (which were remade in "Jurassic Park" film). As a grown up it
might 3-4 metres high. It might have been a rather evolved meat-eater if we consider the
shape and size of its skull, its sharp teeth and limbs. It had a complex digestive tract
and you can notice even its liver print, its paws claw, which might be used to fight, was
very big.
Dal Sasso and Signore palaeontologists, who first of all studied the
fossil, established its age in 113 million years.
The discovery of the only specimen of European dinosaur (only prints
were found in Trentino an in Carso) makes us suppose that, in mesozoic era, Europe might
still have been in contact with Africa, because there were dinosaurs in Africa and
consequently also in the lagoons facing Africa these reptiles might have settled; perhaps
only by chance our dinosaur was entrapped in the lagoon muds and afterwards covered and
fossilised.
Since in Pietraroja lagoon there are very different species of animal
fossils we suppose events which led to a mass death (tanatocenosi) which might have
happened when the environmental conditions became very difficult. Since these fossils lie
in a lot of added layers (the whole out crop is thick only 25-30 cm) we suppose that a lot
of animals died periodically (at intervals).
There might have been a lot of attendant circumstances which gave rise
to this (death of a whole species) tanatocenosi: (volcanic events,
earthquakes, seaquakes, sudden changes in saltness and/or in temperature, large increase
of plankton, lack of oxygen with poisonous gases, silting up, etc
).
But as for Pietraroja, according to the most important scholars, lagoon
tanatocenosi might have been caused by the periodical lack of oxygen which led to an
increase of poisonous gases, so that corpses could not be destroyed by decomposing
bacteria and predators.
Consequently only under those conditions fossilisation and
diagenizzazione processes allow the whole animal to be kept.

Finally is it to ask questions?
What is left about the idea of a park which was meant for studying and
for a cultural and turistic development? Perhaps a territorial obligation" or an
enclosure?
The right to study, to safeguard and keep this estate is not refused to anyone but we
wonder for which sciences sake somebody wants only to take away without returning
anything?
Pietraroja with its fossils should surely deserve much more concern. |