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Re: The Hills Have New Papers
As Jerry mentioned our paper on PALAIOS, I send you my rough translation of
the press release that the Friulian Natural History Museum of Udine sent to
the Italian mass media.
220 MILLION YEARS OLD "CROC" NESTS DISCOVERED IN THE JULIAN ALPS OF
During summer 2003 some researchers of the Padua University discovered a
dozen of odd, circular depressions preserved on the surface of a limestone
bed along the Dogna valley, in the Italian Julian Alps (Udine Province).
They are dated to the interval of the geological time known as Late Carnian
(Triassic period), about 220 million years ago, have a diameter of about
three to five feet (100-160 cm), are two to eight inches (5-20 cm) deep and
surrounded by a rim of petrified mud.
Although no eggs remains were found inside the depressions, the comparison
with similar structures occurring in North and South America suggests that
they are nests of extinct reptiles.
More than ten years before, some trackways were found in the same place but
on a limestone bed surface occurring only four feet (1.3 m) higher in the
rock wall. They belong to reptiles about 6-7 feet (2 meters) long and
walking on four limbs, probably etosaurs, animals vaguely similar to a croc.
According to the paleontologists and geologists of the Padua University
(Paolo Mietto, Daniele Piubelli, Nereo Preto and Manuel Rigo), the CNR
(Comitato Nazionale per la Ricerca Scientifica) of Padua (Guido Roghi), the
Museo Tridentino di Scienze Naturali (Marco Avanzini) and the Museo Friulano
di Storia Naturale (Fabio M. Dalla Vecchia), who studied the specimens and
the geology of the site, the nest maker was probably the same kind of
reptile as the trackmaker.
Supporting this hypothesis is - in addition to the space/time coincidence -
a nests size well corresponding with the size of the trackmakers.
This is the first time that a nesting site of those extinct animals is
The most extraordinary aspect is that the way of nest building is much more
sophisticated and complex than that observed in living crocodiles and
The reptiles of the Dogna valley produced a bowl-like depression, open and
rimmed as that built by some living birds (ostriches and flamingos, for
example). This behaviour, complex and related to the parental care, was
previously considered a characteristic of dinosaurs (birds and some
non-avian dinosaurs), observed in the North American Troodon, a theropod
lived 70 million years ago, over 150 million years after the Italian nests.
To lay eggs, the living crocs dig a simple hole in the sand that they cover
after laying; gators build mounds of dirt and plant fragments containing the
Surprisingly, the reproductive behaviour of some crurotarsal Triassic
reptiles was more advanced (sophisticated) than that of their living
The study of the Italian fossil nests was worth of the cover of the
September issue of the international journal PALAIOS.
HOW THE TRIASSIC NESTS ARE?
They are wide, round depressions, about three to five feet across. They are
surrounded by a raised mud rim up to 8 inches high, made by the animal
pushing outward the sediment, probably by its feet. Because of this, the rim
is not regular but made of distinct mud layers pushed in different times.
The central part of the depressions preserves traces of organic matter of
vegetal origin. Probably they are the remains of plants or algae that
females brought to the nest to warm the eggs with the heat developed by
The nests are close each other and roughly equidistant (around three-four
feet) a fact indicative of social behaviour. Therefore it not the case of
single, isolated nests but a nesting site.
WHO DID THE NESTS?
Crocs and birds are the only living members of a group of Mesozoic
reptiles - the Archosaurs - that had an extraordinary evolutionary success
during the Mesozoic era, between 250 and 65 million years ago. The two main
Archosaur lineages are those that led to the living species. The
Ornithodirans lineage saw the great diversification of the dinosaurs, whose
only living members are the birds.
The lineage leading to the living crocs includes an array of animals that
spread during the Triassic period, between 240 and 200 million years ago,
and are all extinct. They are the phytosaurs, predators at first sight very
similar to crocs; the etosaurs, vegetarians with an armoured body; and the
rauisuchians, ferocious and swift terrestrial predators. With the
crocodylomorphs all those animals form the Crurotarsi group. The first
species of the evolutionary lineage leading to living crocs (that is, the
first crocodylomorphs) were found in rocks about 200 million years old.
Etosaurs, the probable authors of the Dogna valley nests, moved on four legs
as the living crocs, but unlike these they used to keep their feet nearly
vertical below the body, thus their gait was less sprawling. They were
pacific plant-eaters that lived together with the first dinosaurs.
The study of the trackways revealed that the reptiles of the Dogna valley
were about 6-7 feet (two meters) long, with a low and broad body. They did
not crawl the belly and the tail on the ground as other more primitive
reptiles did and still do. They progressed in a rather efficient way keeping
their feet oriented forward instead of pointing them laterally (as, for
examples, crocs as well iguanas do). The hind feet were elongated, with five
toes (crocs have only four) and impressed a footprint about 8 inches (20
centimeters) long, decidedly larger than the subcircular print of the
To lay eggs those animals gathered in a sheltered place, at the margins of a
wide lagoon with shores covered by tropical vegetation, not very far from
the open sea.
The Dogna region is already famous among vertebrate paleontologists for
yielding skeletal remains - slightly older than the nests and also unique -
of other large, extinct reptiles. Among them are the placodont
Protenodontosaurus italicus (a sea reptile vaguely similar to a turtle) and
Bobosaurus forojuliensis, a marine predator about 10 feet long and possible
ancestor of the Jurassic plesiosaurs.
Original press release translated by F.M. Dalla Vecchia
For more information and materials please contact the Museo Friulano di
Storia Naturale (Udine, Italy)
Via Marangoni 39, I-33100 Udine, Italy
the Curator of the Museum
For more info on the PALAIOS issue:
----- Original Message -----
From: "Jerry D. Harris" <email@example.com>
To: "DINOSAUR Mailing List" <firstname.lastname@example.org>
Sent: Wednesday, September 05, 2007 10:46 PM
Subject: The Hills Have New Papers
OK, no they don't...but they _do_ have fossils in 'em...!
Avanzini, M., Dalla Vecchia, F.M., Mietto, P., Piubelli, D., Preto, N.,
Rigo, M., and Roghi, G. 2007. A vertebrate nesting site in northeastern
Italy reveals unesxpectedly complex beahvior for late Carnian reptiles.
Palaios 22(5):465-475. doi: 10.2110/palo.2005.p05-137r.
ABSTRACT: We interpret 13 large subcircular or horseshoe-shaped
depressions discovered in Late Triassic peritidal carbonate rocks of the
Dogna Valley in Udine Province, northeastern Italy, to be reptile nests.
These trace fossils show truncation of strata, elevated ridges of massive
sediment, and sediment infill within the depression differing in shape and
sedimentary structures from the host sediment. The palynological
assemblage of a shaly interbed close to the nest layer indicates a
Tuvalian age (late Carnian). Archosaurian footprints, produced possibly by
aetosaurs, are on a surface 130 cm above the nest-bearing layer. The
trackmakers are considered the most probable nest makers.
Jerry D. Harris
Director of Paleontology
Dixie State College
225 South 700 East
St. George, UT 84770 USA
Phone: (435) 652-7758
Fax: (435) 656-4022
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