“Fossil Art”: The importance and value of the palaeobiodiversity in the Naturtejo Global Geopark, under UNESCO (Portugal)

The Geopark Naturtejo da Meseta Meridional (Centre Iberian Zone, Portugal) is developing the inventory of geological and mining heritage since 2004. This inventory in a concluding stage shows 18 fossil geosites, including classical and newly discovered sites evidencing international to regional importance. Some of the oldest fossils of the Iberian Peninsula were found at Naturtejo Geopark, corresponding to Middle - Late Ediacaran marine cyanobacteria found in a turbidite sequence cropping out at Erges River valley, near Salvaterra do Extremo locality. Most of the inventoried fossil sites belong to the Armorican Quartzite Formation, which is a peri-Gondwanan distributed biofacies famous for its trace fossils, such as the classic Skolithos (in piperock ichnofabrics) and the Cruziana rugosa group, as well as for obolid brachiopod shell beds, but lacking almost any other body fossils. The Penha Garcia Ichnological Park, a popular attraction of Naturtejo Geopark, is becoming internationally recognized for the unusual abundance and preservation of such trace fossils, with remark for the diverse feeding patterns made during the life cycle of giant trilobites. The remaining Ordovician period is well represented by fossil sites with calymenid, illaenid, dalmanitid, trinucleid and pliomerid trilobites, bivalves, orthoceratid cephalopods, orthid brachiopods, didymograptid graptolites, diploporitid echinoderms and ostracod arthropods. Fossils from Lower Silurian age (Llandovery) were found recently and for the first time in Naturtejo Geopark. Graptolites, cephalopods, bivalves and possible remains of eurypterids are among the first fossils identified. In the continental Cenozoic deposits, the fluvial terrace of Pinhal records the first incision of the Tejo River on the Neoproterozoic-to-Lower Palaeozoic and Palaeogene-Neogene rocks of Naturtejo Geopark during lower Pleistocene. In these conglomerates, at least 7 fossil tree trunks were found, due to the erosion by the Tejo river of Middle - Late Miocene aged arkoses and their deposition in flooding plain environment. The fossil trees were found by the Romans almost two thousand years ago during exploitation of the fluvial conglomerates for gold. The most recent fossil site was dated to 33500 years and corresponds to sandstones from the last fluvial terrace developed by the Tejo River. Foz do Enxarrique fossil site provided remains of large mammals such as red deer and auroch. But the most important finding was the remains of Elephas antiquus, corresponding to the latest record of this important elephant before its final extinction from Europe mainland. Fossil sites and palaeontological data achieved from active ongoing research at Naturtejo Global Geopark are being included in several tourism packages and educational programmes proposed by Naturtejo for national and international tour operators and schools. Cruziana trace fossils and trilobites that produced them have become the geobrand for nature tourism and landscape touring, not only for the Geopark area but also for the whole Portuguese Centre Region. Actually, they are already being used in innovative business opportunities.