This exhibit covers about 180 million years, displaying terrestrial vertebrates
from the
Late Permian labyrinthodonts and mammal-like reptiles to the Late Cretaceous
dinosaurs.
Fossils of Permian Period, which ends the Paleozoic Era, and those of the
Triassic
Period, which starts the Mesozoic Era, provoke a special interest. In that time,
approximately
250 million years ago, very important biosphere changes occurred,
including one
of the largest extinction events. In East Europe, the area of the Permian
and
Triassic sediments, containing remains of terrestrial vertebrates, extends
approximately
from Moscow up to the western slope of the Ural Mountains, and from the
coast
of the Arctic Ocean up to the Caspian Lowland. The history of findings of animal
bones
in Permian and Triassic sediments of East Europe goes back many centuries.
Beginning
with the Bronze Age, copper has been mined from coppery sandstone and
slates in
the Ural Mountains. When mining, bones of vertebrate animals were often
found.
In antiquity, these bones were thought to be skeletons of lost miners. Only 160
years
ago, the first scientific descriptions of fossil vertebrates from coppery sandstone
were
published. In 1841-1845, the name Permian system was offered for these deposits
by
Sir Roderich Murchison, an English geologist, after an ancient mythic Perm
Kingdom
of Ural area. The study of the Late Permian tetrapods of East Europe was
begun
by Prof. Vladimir P. Amalitsky at the end of the 19th century. He led unique
excavations
on the Malaya Severnaya Dvina River in the Arkhangelsk Region.
The fossil vertebrates
he found compose a world-renowned collection in the North Dvina
Gallery. The skeletons
of Scutosaurus, Inostrancevia
as well as the skulls of Dicynodon,
Annatherapsidus
and Dvinia, presented in "Russian Dinosaur Exposition"
come from the
North Dvina collection. The modern Russian collections of Permian
and Triassic
terrestrial vertebrates from the territory of East Europe comprise
many thousands of
specimens, belonging to representatives of more than 70 families
of ancient tetrapods.
Systematic diversity of the specimens and their state of
preservation are unique in
comparison with any other collection around the world.
In
the Permian-Triassic part of the exhibition two specimens of the thecodonts,
Archosaurus
and Garjainia, are of particular interest. These forms
represent the early
stage of the archosaurian evolution, which gave rise to the
dinosaurs, pterosaurs,
crocodiles, and birds. With exception of one Early Cretaceous
dinosaur specimen, that
comes from Northern China, all others displaying at the
"Russian Dinosaur Exposition"
have been collected in several Late Cretaceous
localities in the Gobi Desert, Southern
Mongolia. The Late Cretaceous was a time
when many groups of dinosaurs had riched to
their flourishingand then became extinct.
The extinction of dinosaurs is obviously one of
the most impressive events if
the Earth's history. It attracts the lively interest of both
specialists and the
public and provokes diverse hypotheses explaining its causes.
Since time immemorial
Arats, native dwellers of Mongolia, have known about many
places with huge stone
bones. They believed they were remains of terrible dragons.
The first time Mongolia
was discovered as a paleontological Mecca was by the
expedition of the American
Museum of Natural History at the early 1920s.
During three seasons of intensive
excavations, this expedition, headed by
Roy Chapman Andrews and W.Granger, collected
a splendid set of fossils,
including several new forms of dinosaurs.
At the
end of 1940s, paleontological exploration of Mongolia was continued by the
Paleontological
Institute of Moscow. The result of three years of activity under the
leadership
of I. A.Efremov was a large and diverse collection of dinosaurs and ancient
mammals,
as well as discovering of many new localities of fossil fauna and flora.
Among
the most impressive dinosaur speciments found by Efremov's expediton and
displayed
at the "Russian Dinosaur Exposition" are the skeleton and skull of the
giant predatory dinosaur Tyrannosaurus, the skeleton and
fragment of the skin of the
duck-billed dinosaur Saurolophus,
the skeleton of armoured dinosaur Talarurus,
and the
skull of the large hadrosaur Iguanodon.
After Efremov's
expedition, there was a two-decade intermission in the activity of the
Paleontological
Institute in Mongolia until the Joint Russian-Mongolian Paleontological
Expedition
(former Soviet-Mongolian) was organized in 1969.
The next three decades became
a time of very intensive paleontological explorations,
which embraced all principal
groups of vertebrate and invertebrate animals and plants.
Many thousands of specimens
have been collected during that period. These collections
are represented at the
exhibition by specimens of the ceratopsian dinosaurs
Psittacosaurus
and Protoceratops, and the intriguing bird-like dinosaur
Avimimus.
Besides dinosaurs the diversity of Mesozoic
tetrapods are represented by the earliest
known salamander Karaurus
from the Late Jurassic of Kazakhstan and two extremely
unusual gliding reptiles
Longisquama and Sharovipteryx from the
Early Triassic of
Kyrgyzstan. None of these unique specimens has been ever displayed
outside the
Museum of Paleontological Institute in Moscow.
