Graptolites from Peinconi
Site Category: Geological
Peinconi is one of Sardinia's most important paleontological geosites from a scientific, historical, and identity perspective, characterized by Graptolites' fossil remains. The locality is known as Pe 'Inconi, which translated from Sardinian means "lame foot." The fossiliferous outcrops were discovered for the first time in 1838 by Alberto Ferrero della Marmora, who described the site as consisting of "black schists that can be divided into thin plates like the sheets of writing paper, which allow the footprints of these to be glimpsed on both sides singular bodies "(the graptolites). The schists are very carbonaceous, shiny, and stain the hands and alternated with limestone banks of the same geological period. The fossil specimens were studied by Meneghini (1857), who confirmed their belonging to the middle Silurian and precisely to the middle Wenlockian (430-427 Ma). About seventy years later, Gortani's studies (1923) made Goni become a Middle Wenlockian graptolites' classic location. Several graptolites have been identified in these outcrops: Goni is known for the index species Monograptus belophorus (Meneghini, 1857). The graptolites' fossil remains commonly appear as finely serrated silver ribbons that contrast with the host rock's color. During the lower Paleozoic, these animal organisms with colonial ways of life spread and dominated the oceans as main components of zooplankton and are considered important guide fossils for the lower Silurian-Devonian interval. In Sardinia, 155 species of graptolites have been recognized, assembled in 24 biozones covering the period referring to the entire Silurian period from the basal Llandovery to Pridoli. In the Goni section, six biozones of the Wenlockian have been recognized from bottom to top: Monograptus belophorus; Cyrtograptus rigidus; Cyrtograptus ramosus – Cyrtograptus ellesae; Cyrtograptus lundgreni – Testograptus testis; Pristiograptus parvus – Gothograptus nassa; Colonograptus praedeubeli – Colonograptus deubeli; Colonograptsus ludensis – Colonograptus gerhardi.