Monte San Giorgio

Monte San Giorgio is a mountain in the western Pre-Alps between Italy and Switzerland that overlooks the southern part of Lake Ceresio or Lake Lugano.  The Swiss side was included in the Unesco World Heritage List in 2003 (Mendrisio, Brusino Arsizio), while the Italian side was granted the recognition in 2010. The places included in the UNESCO inscription are in the province of Varese and are related to the municipalities of Porto Ceresio, Besano and Viggiù.

Monte San Giorgio appears as a pyramid-shaped wooden mountain overlooking the lake with its 1097 m of height. The exceptional value of this naturalistic area is given by the presence of a fossil sequence related to the Middle Triassic (242-230 million years ago). At that time, the area was a sub-tropical environment, a sort of lagoon: an inlet with a depth of a thousand metres, with islets and sandbanks, separated from the open sea by a carbonate reef of calcareous algae.  This led to sedimentation phenomena that, associated with a low concentration of oxygen in the seabed, allowed the preservation of the fossil of innumerable organisms, which settled in six superimposed layers. The study of the layers allowed to reconstruct the evolution of many species of marine animals with reference to the changes in environmental conditions and over a period of 12 million years. Moreover, of exceptional interest is the finding of different organisms in the same levels and rocky blocks, because this allows to study the natural association of different forms of life.

Monte San Giorgio was already famous in the pre-modern period from the 15^th century for the cropping out of oily fossil organic material mainly consisting of remains of fish and marine reptiles, used to obtain ichthyol used in pharmacopoeia and cosmetics. The scientific interest in and study of oil shales started in the same period of industrial interventions such as quarries and mines aimed at finding fossil fuel. The first excavations date from the second half of the 19^th century; in 1854, naturalist Emilio Cornalia described the finding of some fossil small reptiles, while in 1863 Abbot Antonio Stoppani, considered the father of Italian Geology, carried out the first campaign of paleontological excavations in the area. The long tradition of paleontological studies and orderly management of excavations led to important well documented and catalogued collections of finds used for several scientific publications. The fossil succession of Monte San Giorgio was the main worldwide reference for all future paleontological studies on Triassic marine fauna.

Monte San Giorgio is part of the tectonic unit of the Southern Alps. Many finds are of rare or even unique species, such as Sangiorgiosaurus or Besanosaurus, whose names refer to the toponyms of the area. 21,000 specimens have been found from the first campaigns to the following excavations in the territory, including 30 species of reptiles, 80 species of fish, approximately 100 species of invertebrates, several microfossils and plants, today on display in the Museo Civico di Storia Naturale in Milan, Paläontologisches Museum-Universität in Zurich, Museum of the Institute of Palaeontology in Zurich, Museo Cantonale di Storia Naturale in Lugano, Museo dei Fossili in Meride, Museo Insubrico di Storia Naturale in Clivio, and Museo Civico dei Fossili in Besano (Italy). Visitor reception for the UNESCO area is granted by the visitor-centers of Clivio (Italy) and Meride (Switzerland).

(Switzerland, Meride Limestone, Middle Triassic) is considered a symbol of the fossil heritage of Monte San Giorgio and, indeed, a stamp with the image of Ceresiosaurus was created in 2003 when the Swiss side was added to the World Heritage List. Ceresiosaurus belongs to the nothosaurus family, i.e. reptiles with a long neck, a small head with sharp teeth and paddle shaped limbs, also known as the “Triassic seals” because they were excellent swimmers although they did not live always in the water. In the Monte San Giorgio area, the first findings were made in the ‘30s during excavations coordinated by Bernhard Peyer of the University of Zurich at Acqua del Ghiffo, property of Mr Emilio Calcagni. Several skeletons of ceresiosaurs of different size were found in the site, together with fish, small reptiles and algae.

(Italy, Besano Formation, Middle Triassic). In 1993, the remains of a giant marine reptile were found near Besano, at Cava del Sasso Caldo. It is a new species, a unique specimen, belonging to the ichthyosaur family, and its name Besanosaurus leptorhynchus means “Reptile of Besano with a thin rostrum” since it was characterized by a sort of long beak similar to that of dolphins.  It was six m long and the fossil is complete and intact. It was identified by using X rays on a slab of rock, which required 16,500 hours to be cleaned and prepared by the research group of the Museo di Storia Naturale of Milan. The Besanosaur found was a female, had small cone-shaped teeth and ate squids. A particular detail of the fossil is that the trace of four small vertebral columns can be seen in the abdomen: the embryos inside the mother.

The area of Monte San Giorgio is rich in karstic caves that fuelled popular imagination by giving birth to legends of wizards and kidnapped girls. Manfredo Settala (12^th century), a medieval hermit of noble Milanese origins to which several miracles were attributed, lived there.

Abbot Antonio Stoppani (Lecco, 1824 – Milan, 1891) was an Italian scientist and man of letters. Lecturer of Geology at the Università di Pavia and the Politecnico di Milano, he published the first Italian essay on geology. Collaborator of the Museo Civico di Storia Naturale of Milan, he was also director of the institution from 1882 to his death. He combined research and didactics with his love for “letters” and was an excellent popularizer with his great publishing success Il Bel Paese (1875) about the wonders of unified Italy.

The Dolomites, a naturalistic Site in eastern Italy, tell the history of the Earth (from the end of Palaeozoic to the whole Mesozoic).  Like Monte San Giorgio, the Dolomites were completely different from now, with a large sub-tropical lagoon, islets, coral reefs separated by basins and active volcanoes.  The basin environments promoted the preservation of marine organisms, including reptiles, which settled on the bed upon death.

Il monte San Giorgio: dai fossili alla lavorazione artistica della pietra, una storia di 300 milioni di anni, a cura di M. Felber, Edizioni Casagrande, Bellinzona, 2005.

Monte San Giorgio, a cura di M. Balini, C. Lombardo e B. Grassi, Edizioni SAGEP, Genova, 2015.

M. Felber, Il Monte San Giorgio, Edizioni Casagrande, Bellinzona, 2007.

S. Magnoli, Zac e Lalo. Sulle tracce del Ceresiosauro, Giacomo Morandi Editore, Varese, 2014.

S. Nosotti, G. Teruzzi, I rettili di Besano-Monte San Giorgio, Milano, Società italiana di scienze naturali, Museo di Storia Naturale, 2008.

whc.unesco.org/en/list/1090/

www.unesco.beniculturali.it

www.montesangiorgio.org/

www.unescovarese.com/

Monte San Giorgio is a mountain in the western Pre-Alps between Italy and Switzerland that overlooks the southern part of Lake Ceresio or Lake Lugano.  The Italian places included in the UNESCO inscription are in the province of Varese and are related to the municipalities of Porto Ceresio, Besano and Viggiù.

Monte San Giorgio appears as a pyramid-shaped wooden mountain overlooking the lake with its 1097 m of height. The exceptional value of this naturalistic area is given by the presence of many fossils from the Middle Triassic. At that time, the area was a sub-tropical environment, a sort of lagoon: an inlet with a depth of a few thousand metres, with islets and sandbanks, separated from the open sea by a reef of calcareous algae.  These conditions promoted the settling of carcasses on the seabed; thanks to the limited circulation of water inside the lagoon and the low concentration of oxygen, the remains of flying, terrestrial or marine reptiles and other organisms (especially fish) remained intact and became fossils, imprisoned in the layers of rocks and sediments.

In the Middle Ages, Monte San Giorgio was famous for ichthyol, which was extracted from oily fossil organic material, mainly composed of remains of fish and marine organism and used as a medicine for the skin. In the 19^th century, excavations started in the area aimed at finding fossil fuel, since the oil shales of the area were suitable for different industrial uses. The first scientific excavations date from the second half of the 19^th century; in 1854, naturalist Emilio Cornalia described the finding of some fossil small reptiles, while in 1863 Abbot Antonio Stoppani, considered the father of Italian Geology, carried out the first campaign of paleontological excavations in the area. The long tradition of paleontological studies and orderly management of excavations led to important collections of finds used for several scientific publications. The fossil succession of Monte San Giorgio was the main worldwide reference for all future paleontological studies on Triassic marine fauna.

Many Monte San Giorgio finds are of rare or even unique species, such as Sangiorgiosaurus or Besanosaurus, whose names refer to the toponyms of the findings. 21,000 specimens have been found from the first campaigns to the following excavations in the territory, including 30 species of reptiles, 80 species of fish, approximately 100 species of invertebrates, several microfossils and plants, today on display in the Museo Civico di Storia Naturale in Milan, Paläontologisches Museum-Universität in Zurich, Museum of the Institute of Palaeontology in Zurich, Museo Cantonale di Storia Naturale in Lugano, Museo dei Fossili in Meride, Museo Insubrico di Storia Naturale in Clivio, and Museo Civico dei Fossili in Besano (Italy). Visitor reception for the UNESCO area is granted by the visitor-centers of Clivio (Italy) and Meride (Switzerland).

(Switzerland, Meride Limestone, Middle Triassic) is considered a symbol of the fossil heritage of Monte San Giorgio and, indeed, a stamp with the image of Ceresiosaurus was created in 2003 when the Swiss side was added to the World Heritage List. Ceresiosaurus belongs to the nothosaurus family, i.e. reptiles with a long neck, a small head with sharp teeth and paddle shaped limbs, also known as the “Triassic seals” because they were excellent swimmers although they did not live always in the water. In the Monte San Giorgio area, the first findings were made in the ‘30s during excavations coordinated by Bernhard Peyer of the University of Zurich at Acqua del Ghiffo, property of Mr Emilio Calcagni. Several skeletons of ceresiosaurs of different size were found in the site, together with fish, small reptiles and algae.

(Italy, Besano Formation, Middle Triassic). In 1993, the remains of a giant marine reptile were found near Besano, at Cava del Sasso Caldo. It is a new species, a unique specimen, belonging to the ichthyosaur family, and its name Besanosaurus leptorhynchus means “Reptile of Besano with a thin rostrum” since it was characterized by a sort of long beak similar to that of dolphins.  It was six m long and the fossil is complete and intact. It was identified by using X rays on a slab of rock, which required 16,500 hours to be cleaned and prepared by the research group of the Museo di Storia Naturale of Milan. The Besanosaur found was a female, had small cone-shaped teeth and ate squids. A particular detail of the fossil is that the trace of four small vertebral columns can be seen in the abdomen: the embryos inside the mother.

The area of Monte San Giorgio is rich in karstic caves that fuelled popular imagination over the centuries by giving birth to legends of wizards and kidnapped girls. Manfredo Settala (12^th century), a medieval hermit of noble Milanese origins to which several miracles were attributed, lived there.

Abbot Antonio Stoppani (Lecco, 1824 – Milan, 1891) was an Italian scientist and man of letters. Lecturer of Geology at the Università di Pavia and the Politecnico di Milano, he published the first Italian essay on geology. He was an important expert of the Monte San Giorgio area. Collaborator of the Museo Civico di Storia Naturale of Milan, he was also director of the institution from 1882 to his death.

The Dolomites, a naturalistic Site in eastern Italy, tell the history of the Earth (from the end of Palaeozoic to the whole Mesozoic).  Like Monte San Giorgio, the Dolomites were completely different from now, with a large sub-tropical lagoon, islets, coral reefs separated by basins and active volcanoes.  The basin environments promoted the preservation of marine organisms, including reptiles, which settled on the bed upon death.

Oil shales, blackish sedimentary rocks, rich in organic oils and spathic.

Invertebrates, animals with no vertebral column, e.g. insects, worms, molluscs and arthropods.

Embryo, the first development stage of a complex organism from fertilisation of the ovum to cellular differentiation with the beginning of the different organs.