Eocene Marine Biodiversity of the Alpone Valley

Description

Overall, the fossiliferous deposits of the Alpone valley constitute a natural site of universal importance. The serial site “Eocene Marine Biodiversity of the Alpone valley” consists of 39 fossil deposits located in the province of Verona, in north-east Italy. The Alpone valley, named after the watercourse descending it, covers an area of about 16,700 hectares with altitudes ranging from 30 to 925 meters above sea level. Its territory is characterized by extensive outcrops of volcanic rocks with gentle and undulating morphology, punctuated by soaring conical shapes locally known as “purges” (Purga di Bolca, Purga di Durlo) and by the remains of ancient volcanic “structures” (Monte Calvarina, Monte Crocetta, Monte Castello and Monte del Diavolo). The volcanic rocks contain a number of olistolites of a variety of sizes of marine sedimentary rocks, comprising abundant and significant fossil deposits mostly dating back to the Eocene (between 56 and 34 million years ago), a period characterized by important biological, climatic, environmental and geodynamic changes.

The 39 deposits – some better known, others less famous – form a unified heritage site, despite their composite location, and have specific characteristics in which three main types or categories of fossil finds can be recognized: (a) marine vertebrates, (b) terrestrial vertebrates and (c) marine invertebrates. Their excellent preservation, size, biodiversity and uniqueness (mainly fish, crustaceans and marine mollusks, plus continental vertebrates, insects and terrestrial plants), as well as the variety of the fossil deposits, are essential elements for defining the main features of the Eocene tropical marine ecosystems.

For centuries, the extraordinary Eocene fauna of the Alpone valley played a crucial role in phylogenetic studies and in the reconstruction of paleoclimatic, paleoecological and paleobiogeographical aspects of the ancient Tethys sea, as demonstrated by the long history – almost 500 years – of scientific research, and by the large number – over 800 – of relevant publications.

Justification of Outstanding Universal Value

The 39 fossil deposits of the Alpone valley allow a comprehensive definition of a unique scenario of the Eocene tropical marine biodiversity. The various deposits (two of which are in the adjacent upper Chiampo valley) form a serial site in which three main types or categories of fossils may be recognized:

1. marine vertebrates (bony and cartilaginous fish, mammals) that characterize the deposits denominated Pesciara Monte Postale and Monte Duello;
2. terrestrial vertebrates (crocodiles, turtles and birds) that characterize those of the Purga di Bolca, Monte Vegroni and Pesciara;
3. marine invertebrates (bivalves, gastropods and crustaceans), which mainly characterize the deposits of Valle della Chiesa, Ciupìo, Monte Serea and Monte Duello.

There is nothing worldwide to equal the extraordinary preservation quality of the vertebrates, invertebrates and plant remains, especially the size, extraordinary diversity and uniqueness of the fossil fishes, including numerous anatomical structures usually not prone to survive the fossilization processes. The various sites include the absolute icon of Italy’s paleontological heritage, the “Pesciara” of Bolca. Celebrated for about five centuries for the exceptional beauty and importance of its finds, it is one of the most studied deposits in the world also representing the fossil site with the greatest biodiversity of vertebrate remains.

Both early excavations, which began before 1550, and important recent paleontological research, scientifically conducted, have provided essential contributions to the knowledge of the evolution of the Eocene tropical marine and terrestrial environments.

These deposits, both in the past and in ongoing excavations, have yielded and continue to yield unique information about the conspicuous biodiversity of the Eocene fauna and flora. Among the well preserved fossils there are numerous bony and cartilaginous fish, but also crocodiles, turtles, snakes, birds, gastropods, bivalves, cephalopods, crustaceans, corals, worms, jellyfish, insects, marine and terrestrial plants – the latter very often associated with flowers and fruits. They are the most complete fossil evidences of a very important phase in the history of the Earth, and have provided a comprehensive and detailed picture of the tropical coastal marine life during the Eocene. The structure and composition of the fauna and flora from these deposits provide a unique evidence of the complete recovery of marine biodiversity after the most recent mass extinction that characterized the long history of our planet.

Each single deposit has contributed and continues to contribute, to a varying extent but in a complementary fashion, to the rich fossil heritage which is collected, restored, studied and exhibited in museums all over the world.

Criterion (viii): The Eocene paleontological heritage of the Alpone valley consists of 39 diversified fossil deposits, two of which are topographically located outside the valley, although historically associated with it. Taken together, these deposits form an excellent and complete representation of unique efficacy in documenting the main features of the marine biotic communities of the Eocene era, which covers a time interval between 56 and 34 million years ago. This situation, unlike any other in the world, allows us to better define the characteristics of an extraordinary biodiversity hotspot which, as a result of changes in the geographical configuration of Eurasia and the Afro-Arabian plates, gradually moved eastwards to settle in its current position, the so-called East India triangle located between Indonesia, the Philippines and the South China Sea.

The excavations and studies conducted for centuries in the deposits of the Alpone valley, still ongoing, are documented by an enormous number of publications (over 800), which have provided a fundamental contribution to paleontological research and knowledge of the Eocene history of life of our planet. The deposits’ importance and distinctiveness are demonstrated by the attention long shown them by paleontologists, geologists, other scholars and travellers, thereby making this serial site unique and exceptional.

Fossil specimens from theese deposits are currently exhibited both in local museums and in the world’s main natural history museums, contributing to the preservation, study and dissemination of knowledge of the Eocene marine paleontological heritage.

The exceptional preservation of the fossils, which in the case of fish often allows the recognition and reconstruction of anatomical structures that rarely fossilize, their concentration and considerable diversity and uniqueness of the finds and, finally, their phylogenetic and paleoecological significance concur to emphasize the relevance of paleobiological research to contribute to a comprehensive and complete understanding of the multi-layered history of biological, climatic and environmental variations of the Eocene marine biota.

Statements of authenticity and/or integrity

The 39 deposits making up the serial site bring together extremely varied components of the Eocene epoch, but also relate to a broader geological context. They benefit from the full protection of geopalentological resources recognized for assets of this type by the Italian state. Fossil deposits are subject to a clear legislative regulation, hinging mainly on the “Code of Cultural Heritage and Landscape”; furthermore, the two most important deposits (Pesciara and Monte Postale) are each subject to specific legal restrictions. The Code of Cultural Heritage and Landscape requires that the State and Regions guarantee the knowledge, protection, planning and management of territory in relation to the diverse values associated with its various constituent elements. In order to achieve this purpose, the State and Regions must subject territory to specific norms for its use, through landscape plans or urban-territorial plans with specific attention to landscape issues.

All the elements that contribute to define the universal value of the serial site may be found in its 39 deposits, if considered together.

The planning currently in force in the territory proposed for UNESCO candidacy is arranged into several levels: (a) the Regional Territorial Coordination Plan; (b) the Provincial Territorial Coordination Plans (PTCP) of the Provinces of Verona and Vicenza; (c) municipal (PAT) and inter-municipal (PATI) land use plans ; (d) planning by the Lessinia Regional Natural Park Authority.

The management and monitoring of the sites are currently under the responsibility of the Superintendence of Archeology, Fine Arts and Landscape of Verona, Rovigo and Vicenza, the Civic Museum of Natural History in Verona and – more in general – of the Ministry of the Environment and MIBACT (Ministry of Cultural Heritage and Activities and Tourism).

The territory on which the deposits are located has not been affected by urbanization or infrastructures: its scientific value has therefore remained unchanged over time.

Use of correct technique in extracting the fossils of the Alpone Valley during more recent scientific research has maintained intact their value and extraordinary preservation, so allowing a full, comprehensive  reconstruction of biotic, climatic and environmental variations, as well as favouring understanding of their phylogenetic and paleoecological significance. The abundance of fossil remains extracted in the past has not in any way impoverished the deposits, allowing for new and modern excavation campaigns, carried out according to directives provided by MIBACT and by the Superintendence of Archeology, Fine Arts and Landscape of Verona, Rovigo and Vicenza.

The consolidated collaboration between Verona’s Civic Museum of Natural History and the University of Padua’s Museum of Geology and Paleontology – the two museums which house the largest share in the world of the Alpone valley’s historical collections – guarantees that the criteria of integrity are met in an exemplary fashion.

A further part of this priceless paleontological heritage, which has played a fundamental role in the history of science, is currently preserved in two public museums local to the Alpone valley: the Fossil Museum in Bolca, and the Paleontological Museum in Roncà. Other museums, located in both Europe and the United States of America, possess paleontological finds from the Alpone valley – the relevant list is held in the archives of the Civic Museum of Natural History in Verona.

All of these elements concur to define the universal value of these paleontological sites.

Modern studies conducted on the serial site are part of a major scientific research project involving the Civic Museum of Natural History in Verona and numerous other Italian and foreign institutions, both universities and museums. The results of such researches are published in Italian and international journals, including “Studi e ricerche sui giacimenti terziari di Bolca”, a paleontological miscellany published by the Civic Museum of Natural History of Verona since 1969. Other studies are published in Rivista Italiana di Paleontologia e Stratigrafia, Bollettino della Società Paleontologica Italiana, Journal of Vertebrate Paleontology, Palaeontology, Acta Palaeonologica Polonica, Journal of the Geological Society of London, Geological Magazine, Journal of Paleontology, Palaeo-3, Palaios, etc.

Comparison with other similar properties

Outside Italy there are a number of other world-famous Eocene fossiliferous localities. For instance, the paleolakes of Grube Messel (Hesse, Germany) - known for the extraordinary mammals – and Kemmerer and Green River Formation (Wyoming, USA); however, their finds are not comparable in terms of diversity with those of the Alpone valley. If we look at fish fauna, for example, Grube Messel and Green River Formation include about three dozen of species (in any case less than 40), as compared to more than 260 known for the Pesciara site alone. Wadi Al-Hitan (Egypt), on the other hand, only documents the evolution of the archeocetans (archaic cetaceans) of the Eocene epoch. The Pesciara di Bolca is recognized as one of the seven most important Konservat-Lagerstatten in the world and. Considering its exceptional nature, it is comparable if not superior to other celebrated paleontological sites, including: the Triassic site of Monte San Giorgio (I, H), the Jurassic sites of Holzmaden (D) and Solnhofen (D), the Eocene sites of Green River (US) and Messel (D). The Messel site is already registered in the UNESCO World Heritage List as a crucial paleontological site for reconstructing the evolution of mammals in the Eocene era, while the Monte San Giorgio site is included in the List for the marine fauna of the Middle Triassic.

The Eocene geopaleontological heritage of the Alpone valley is therefore unique of its kind. There is nothing similar in the rest of the world, due to the long history of research (almost five centuries) and the large number of publications (over 800), as well as for the exceptional preservation size, biodiversity and uniqueness of the fossil finds (mainly fish, crustaceans and marine mollusks, continental vertebrates insects and terrestrial plants), and, finally, for the variety of fossil deposits located along the valley.