Bollettino del Museo Civico di Storia Naturale di Verona, 36, 2012 Geologia Paleontologia Preistoria: 45-52 Introduction Sponges are among the most ancient extant mul- ticellular animals (Hooper & van Soest, 2002). Due mostly to the low preservation potential of many taxa, especially those with organic skeleton only, sponge fossil record is rather incomplete. Moreover, Ceno- zoic siliceous sponges are insuiciently studied (Pisera, 1999 and 2006). Regarding the Eocene, the word- wide record of siliceous sponges is quite scarce and includes Spain (Pisera and Busquets, 2002), North Carolina (Finks et al., 2011 and literature herein) SW Australia (Gammon et al., 2000 and literature herein), New Zealand (Hinde and Holmes, 1892; Kelly and Buckeridge, 2005). In Italy, there is only one (Middle) Eocene reported occurrence of siliceous sponges, in Chiampo Valley (Lessini Mountains, NE Italy) (Menin, 1972; Visentin, 1994; Matteucci and Russo, 2005 and 2011). his study reports the presence of siliceous sponge spicules found during excavations at Monte Duello, Montecchia di Crosara (Verona, NE Italy) in Bartonian marls (Fig. 1). he aim of this note is to give a prelimi- nary account of this assemblage, with description and illustration of the isolated spicules found this far. Materials and methods he spicules described were studied under optical microscopes. Two methods were used: 1. Preparation for optical binocular microscope, re- lected light At Padova University, Micropalaeontology Labora- tory, bulk rock samples were broken in pieces of 1- 2 cm of diameter, treated with H 2 0 2 15% (Bonci et al., 1997) and then washed on 125 and 63 µm sieves. Some samples were dissolved in 10% HCl to verify if the spicules were siliceous. he spicules were picked under a Leica MZ 125 binocular mi- croscope. Photos were taken with Nikon D300, software Nikon CAMERA CONTROL PRO2 2. Optical microscope, trasmitted light At Museu Nacional of Universidade Federal do Rio de Janeiro (Brazil), Porifera laboratory, bulk rock Preliminary study of isolated siliceous sponge spicules from Monte Duello, Montecchia di Crosara (Lessini Mountains, Verona, NE Italy) VIVIANA FRISONE*, ROBERTO ZORZIN** (*Museo di Archeologia e Scienze Naturali “G. Zannato”, Montecchio Maggiore (Vicenza); Università degli Studi di Padova; **Museo Civico di Storia Naturale di Verona) Abstract Bartonian marls of Monte Duello, Montecchia di Crosara (Verona, NE Italy), contain isolated siliceous sponge spicules here described and il- lustrated for the irst time. he spicules were observed under optical microscopes and their identiication performed by comparison with Recent sponges. Nearly all spicules belonged to Demospongiae Sollas, 1885 class, mostly “soft sponges” but also the rigid skeleton ‘lithistids’. Moreover, some Hexactinellida Schmidt, 1870 spicules were also found. Spicules are preserved as opaline silica but very fragmented .To achieve a more precise taxonomic assignment further studies are necessary using scanning-electron microscope (SEM) and extracting spicules from the rock with more adequate methods. Keywords: siliceous sponges, Demospongiae, Hexactinellida spicules, Eocene, Lessini Mountains, Monte Duello, Italy. Riassunto Le marne bartoniane del Monte Duello, Montecchia di Crosara (Verona, NE Italia), contengono spicole isolate di spugne silicee qui de- scritte e illustrate per la prima volta. Le spicole sono state osservate con microscopi ottici e la loro identiicazione è stata efettuata tramite il confronto con spugne attuali. Quasi tutte le spicole appartengono alla classe Demospongiae Sollas, 1885, per la maggior parte alle “spugne molli” ma anche ai “litistidi”, spugne dallo scheletro rigido. Sono state inoltre trovate alcune spicole di Hexactinellida Schmidt, 1870. Le spicole appaiono molto frammentate e conservate in silice opalina originaria. Per ottenere una determinazione tassonomica più accurata sono necessari ulteriori studi utilizzando il microscopio elettronico a scansione (SEM) ed estraendo le spicole con metodi più adeguati. Parole chiave: spugne silicee, Demospongiae, Hexactinellida spicole, Eocene, Monti Lessini, Monte Duello, Italia.