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Figure 2. Mediterranean distribution of the main vermetid reefs cited in the text. The light grey stripe indicates the
megatransect described in section 4 of the text. Dot size is proportional to reef surface length. White dots indicate sites
sampled along the megatransect.

although Laborel [13] recorded them in the north of Corsica, though further confirmation by
direct observation is needed.

The present-day distribution of vermetid reefs includes the central-southern Mediterranean
Sea, although they are more frequently found in eastern areas of the basin (Figure 2). The largest
structures, developed as reefs or atolls, were described along the Israeli coasts [14–16], although
living vermetid reefs are progressively disappearing in this region (G. Rilov, pers. comm.). A
similar situation occurs in Lebanon, where vermetid formations are evenly distributed along the
coast [17], but living reefs are present in only a few locations (Sidon, Tyre). This may be linked
to oil spills and cleaning operations following the 2006 war (S. Silenzi, pers. obs.). Reefs have
also been reported in southern Turkey and Crete [13]. Along Maltese shores, vermetids developed
mainly as crusts and ledges [18], although the presence of some true reefs is acknowledged [19].
Vermetid platforms have been observed at Tipaza and Fouka-Marine in Algeria [20] and small
formations have been found along Mediterranean Moroccan coasts (Gofas S.) [21]. In Spain,
vermetid formations are mainly distributed between Cap de la Nao (near Alicante) and Cabo de
Gata (Almeria) in the southeast Iberian Peninsula [21,22]. Some well-developed bioconstruc-
tions have also been described in Ibiza and Formentera in the Balearic Islands [21,22]. Along
the continental shores of Italy there are no published studies on the distribution of vermetids,
although some structures are known on the Island of Licosa (Campania; G.F. Russo, pers. comm.),
in Campomarino (Taranto – Apulia; S. Silenzi, pers. comm.), and in Capo Rizzuto (Calabria;
S. Silenzi, pers. comm.). Dendropoma petraeum has been reported on the island of Ischia, in
the Gulf of Naples [23], and on northwest coasts of Sardinia, between Capo Figari and Tavolara
Island, with a ledge morphology [11]. Large reefs are found in northern Sicily, between Milazzo
Cape and the coast of Trapani with the Egadi Islands. Some small reefs, shaped as ledges and
encrustations, are also found around Taormina and Syracuse, on the eastern coast of Sicily, and
on the islands of Lampedusa and Ustica [9,12].

4. Vermetid reefs as natural archives of past climatic variations

Vermetid reefs have only recently been recognised as natural archives for reconstructing past
sea-surface temperature variations and sea-level changes [4,6,7,24]. Vermetid bioconstructions
are widely distributed in the Mediterranean basin, located between the lower mesolittoral and the