The Ursus spelaeus
finding environment. (a) Image of the Grotta all’Onda cave from the above, showing the well-defined cut of the Mt. Matanna flank where the cave is located; (b) image of the entrance of the Grotta all’Onda cave; (c) image of the soil stratigraphy from which the Ursus spelaeus
fossil remains have been sampled during the 1999 field campaign; (d) geological sketch map of the area around the Grotta all’Onda cave (http://www502.regione.toscana.it/geoscopio/geologia.html#
). Formation of the Tuscan Nappe unit: LIM: “Calcare Secifero di Limano
” formation; RSA: “Rosso Ammonitico
” formation; MAS: “Calcare Massiccio” formation; RET: “Raethavicola Contorta
” formation, Late Triassic dolomitic-limestones; ctc: cataclastic formation made by a polygenic breccias of mainly metamorphic limestone clasts. Tuscan metamorphic units: PSM: “Pseudomacigno” formation; MCP: “Cipollini” formation.