Calcare di Aurisina

The Calcare di Aurisina is a Mesozoic geologic formation in Italy and Slovenia. This limestones are found in the Trieste area and are of Late Cretaceous age, being a local record of Carbonate platform limestones, historically quarried by cutting large blocks using steel wire, what has allowed more access to them, as numerous quarries allow excellent exposure. Due to being cut into large blocks and slabs, that usually end stored near the quarries, detailed, three-dimensional study of the rock's composition and fossils can be easily done.

Characteristics

The Aurisina limestone has usually a light grey background, sometimes appearing hazelnut in color. It is known for its high purity, compactness, and uniformity. The quarries where it is extracted consist of thick, solid layers of stone. Different varieties of Aurisina marble are distinguished by shades of grey and the distribution, size, and orientation of the organic remains within the stone. Well-known varieties include Aurisina Fiorita, Aurisina Lumachella, Aurisina Chiara, and Roman Stone, among others.
Aurisina marble's chemical composition and physical properties make it ideal for use in architecture, both for structural and decorative purposes, as well as in statues and monuments. The stone is valued for its durability and aesthetic appeal in various applications.

Historical Importance

The Aurisina Limestone has been used since the Roman Republic. Evidence from ancient monuments in Aquileia, a Roman colony founded in 181 BC, suggests that quarrying began in the 1st century BC and continued until the 5th century AD. The stone was widely used in Aquileia for architectural elements, statues, and funerary monuments. The nearby city of Tergeste also made extensive use of Aurisina Limestone for public buildings and sculptures. Its use spread across northern Italy, with artifacts found as far as Pavia.
In the post-Roman period, Aurisina marble was notably used in the Mausoleum of Theodoric in Ravenna, built around 520 AD. However, its use declined during the medieval and Baroque periods. In Venice, it was replaced by Istrian stone, but in Trieste, it saw a revival in the 18th century as the city grew following the establishment of the free port by Emperor Charles VI. Notable examples of its use in Trieste include Palazzo Pitteri, the Stock Exchange, and the renovation of the Greek Orthodox Church of San Nicolò dei Greci.
Aurisina Limestone's "golden age" came under the Austro-Hungarian Empire, particularly after the completion of the Southern Railway, connecting Trieste to Vienna. The stone was used in major projects throughout the empire, including the Parliament and Hofburg in Vienna, the State Opera in Budapest, and many buildings in cities like Graz, Munich, and Ljubljana. By 1890, the industry employed over 3,000 workers.
After Trieste's annexation to Italy in 1918, Aurisina Limestone was used in large-scale projects like the Military Shrine of Redipuglia and Milan's Central Station, where 38,000 tons were utilized. During this period, the marble also reached international markets, being used in Egypt and the United States.
In the post-war era, Aurisina Limestone continued to be popular in foreign markets, with notable projects including the Atlanta subway in the U.S., Berlin airport, and La Défense in Paris. In 1989, it was used for Milan Metro's Line 3. More recently, it has featured in prestigious architectural projects, such as Milan's Citylife Shopping District designed by Zaha Hadid and Turin's Lavazza headquarters. Internationally, it is used in projects across Europe, Asia, Australia, and the U.S.

Paleoenvironment

The formation is characterized by lagoonal facies with episodes of higher energy and rare bivalve patch reefs, such as Chondrodonta and Rudists, which are found throughout the entire unit. The lower section, referred to as the "Zolla member" consists of bivalve-rich limestone, including rudists and Chondrodonta, as well as foraminiferal limestone, often interbedded with dolomitized dark wackestones. In the upper part of this member, pelagic limestone with Pythonella fossils is present. The main body of the Aurisina Limestone is characterized by peritidal carbonates, with some dark laminated facies, dominated by rudists, benthic foraminifera, cyanobacteria, and algae. The Paleoenvironment of this unit is accepted to be a succession of emerged and shallow marine carbonate platform settings, including inner lagoons, high-energy shoals, tidal channels, and rudist accumulations The complex dolomitization and silicification in the region may be linked to a Monsoon climate with alternating wet and dry periods. Comparable dolomitization occurs across the Adriatic Platform, particularly in the Middle-Lower Cenomanian.
The Villaggio del Pescatore fossil site records a progressive environmental shift from a stable shallow-marine carbonate platform to a restricted, tectonically controlled basin. Initially, the area was a protected inner platform with shallow, calm seas, where early sediments accumulated in poorly oxygenated lagoons before giving way to better-ventilated marine conditions with normal salinity. Rudist-bearing facies developed during this stage, though their small size suggests ecologically stressed conditions. Later, higher-energy shallow-marine settings produced bioclastic sands and rudstones under well-oxygenated conditions. During the Lower Senonian, synsedimentary tectonic activity disrupted the platform, creating a small fault-bounded depression. Differential block movements led to erosion of emergent areas and collapse of basin margins, generating polygenic breccias composed of reworked platform material, including clasts showing oxidation, pedogenic alteration, and evidence of subaerial exposure. As tectonic activity decreased or relative sea level rose, clastic input diminished and the basin evolved into a quiet, restricted water body. The depression was progressively filled by finely laminated limestones deposited under low-energy conditions with limited circulation and oxygen-poor bottom waters. Seasonal lamination indicates cyclic sedimentation, consistent with fluctuating freshwater input and variable salinity in a brackish lagoon or shallow coastal lake. Microfossils, freshwater algae, plant traces, and slump structures reflect continental influence and ongoing instability along the basin margins. These anoxic conditions enabled exceptional preservation of vertebrate remains, including hadrosaurs, crocodyliforms, fish, and crustaceans. The surrounding bauxite and coal deposits indicate a humid climate and a karst landscape where surface water was scarce, making the basin a persistent water source. The depression likely functioned as a cenote-like feature that attracted animals, some of which drowned and were preserved at its stagnant base. A subsequent Upper Santonian transgression restored open-marine carbonate platform conditions, sealing the restricted basin deposits and preserving the unique fossil record.

Biota

Foranimifera

Unnamed Miliolidae and Rotaliidae tests are know from Villaggio del Pescatore.

Genus	Species	Location	Material	Description	Images
Accordiella	A conica	Slivia quarries Villaggio del Pescatore	Tests	Benthic zone Chrysalidinidae
Calveziconus	C. cf. lecalvezae	Villaggio del Pescatore	Tests	Benthic zone Dictyoconinae
Cuneolina	C. spp.	Slivia quarries	Tests	Benthic zone Cuneolinidae
Dicyclina	D. schlumbergeriD. spp.	Slivia quarries Villaggio del Pescatore	Tests	Benthic zone Dicyclinidae
Fleuryana	F. adriatica	Villaggio del Pescatore	Tests	Benthic zone Charentiidae
Goupillaudina	G. cf. daguini	Villaggio del Pescatore	Tests	Benthic zone Osangulariidae
Keramosphaerina	K. tergestina	Slivia quarries Villaggio del Pescatore	Tests	Benthic zone Keramosphaeridae
Metacuvillierinella	M. sp.	Villaggio del Pescatore	Tests	Benthic zone Rhapydioninidae
Moncharmontia'	M. apenninicaM. spp.	Slivia quarries Villaggio del Pescatore	Tests	Benthic zone Charentiidae
Murciella'	M. cuvillieriM. spp.	Slivia quarries Villaggio del Pescatore	Tests	Benthic zone Rhapydionininae
Murgella	M. lata	Villaggio del Pescatore	Tests	Benthic zone Praerhapydionininae
Neorotalia	N.? cretaceaN.? cf.cretacea	Villaggio del Pescatore	Tests	Benthic zone Pararotaliinae
Pilatorotalia	P. pignattiiP. spp.	Villaggio del Pescatore	Tests	Benthic zone Calcarinidae
Pseudocyclammina	P. sphaeroideaP. spp.	Slivia quarries Villaggio del Pescatore	Tests	Benthic zone Amijellinae
Reticulinella	R. fleuryi R. maxima R. cf.maximaR. scarsellai	Slivia quarries Villaggio del Pescatore	Tests	Benthic zone Loftusiidae
Scandonea	S. mediterraneaS. samnitica''	Slivia quarries Villaggio del Pescatore	Tests	Benthic zone Praerhapydionininae

Arthropods

Rare to common Ostracod fragile smooth shells are seen at Villaggio del Pescatore.

Genus	Species	Location	Material	Description	Images
Caridea	Indeterminate	Villaggio del Pescatore Polazzo	Multiple specimens	Shrimps resembling extant Neocaridina.
Cirolanidae	Indeterminate	Villaggio del Pescatore	MCSNT 57229	Isopods similar to Cirolana.
Heteroptera	Indeterminate	Villaggio del Pescatore	MCSNT 72/88	Insects similar to modern Closterotomus.
Palaemon?	P. sp. P. cf.antonellae	Villaggio del Pescatore	Multiple specimens	Palaemonidae Shrimps similar to extant Palaemon.

Cnidaria

Stony coral polyps or fragments are seen in Villaggio del Pescatore.

Genus	Species	Location	Material	Description	Images
Jellyfish	Indeterminate	Dobravlje	BJ 1660, body impression	It has a diameter of 2.5 cm
Hydnophora	H. multilamellosa	Lipica	Impressions	Merulinidae stony coral

Echinodermata

Abundant sea urchins spines/radioles and rare cases, as well Crinoid stem fragments/entrochi are know from Villaggio del Pescatore.

Genus	Species	Location	Material	Description	Images
Saccocomidae	Indeterminate	Križ, southwest of Tomaj	Ossicles	Free living Crinoids

Bony Fish

At least 120 small fishes and other of larger size are know from Villaggio del Pescatore.

Genus	Species	Location	Material	Description	Images
Anguilliformes	Indeterminate	Polazzo	Single complete specimen	This would be the oldest anguilliform found in Italy
Cypriniformes?	Indeterminate	Polazzo	Several small complete and incomplete specimens	This determination still needs to be confirmed
Enchodus	E. spp.	Polazzo Dobravlje Križ, southwest of Tomaj	Several small complete and incomplete specimens	A member of Enchodontidae
Heckelichthys	H. microdon	Križ, southwest of Tomaj	BJ1521, complete specimen	A member of Ichthyodectidae, previously referred to Chirocentrites.
Holocentridae	Indeterminate	Polazzo	Several small complete and incomplete specimens	Represented mostly by small-sized specimens
Hoplopteryx	H. stachei	Križ, southwest of Tomaj	BJ1566, subcomplete specimen	A member of Beryciformes.
Ichthyodectidae	Indeterminate	Križ, southwest of Tomaj	BJ2198, subcomplete specimen; Referred BJ396, BJ1659, BJ1730, BJ2198
Palaeobalistum	P. spp.	Polazzo	Several small complete and incomplete specimens	A member of Pycnodontidae
Parachanos	P. ssp.	Polazzo	Several isolated and articulated remains	A member of Chanidae. The attribution to this genus is dubious
Polazzodus	P. coronatusP. gridelli	Polazzo	Multiple complete specimens and isolated teeth	A member of Pycnodontidae
Pycnodontiformes	Indeterminate	Polazzo Križ, southwest of Tomaj	Multiple complete specimens and isolated teeth	Some specimens have been referred to the genus Coelodus
Rhynchodercetis	R. acutissimusR. spp.	Polazzo Križ, southwest of Tomaj	Multiple specimens, complete and incomplete	A member of Dercetidae. The most abundant genus at Polazzo
Sloveniantriacanthus	S. saksi	Šepulje, east of Tomaj	PMS, VS-001, single specimen	A member of Cretatriacanthidae

"Algae"

Freshwater Characeae gyrogonites, oogonia, and whorls/verticilli are found in Villaggio del Pescatore.

Genus	Species	Location	Material	Description	Images
Decastronema	D. kotori	Villaggio del Pescatore	Imprints	Mat-forming blue-green algae
Thaumatoporella	T. ssp.	Slivia quarries Villaggio del Pescatore	Imprints	Potentially an encrusting Green algae

Flora

Palynology of the Villaggio del Pescatore section has been studied, dominated by a few gymnosperms and several angiospermous pollen types. The distribution of plants in this outcrop include: pollen from tropical lowland plants ; pollen from taller trees from more temperate uplands; possible rhizoliths.

Genus	Species	Location	Material	Description	Images
Araucarites	A.? sp.	Dobravlje Kazlje Križ	Isolated Cones	Conifer cones related with Araucariaceae
Brachyphyllum	B. "sp. nov."B. spp.	Dobravlje Kazije Križ Polazzo	Isolated Branched Shoots	Conifer shots related with Araucariaceae or Hirmeriellaceae.
Cunninghamites	C. cf. elegans	Polazzo	Isolated Branched Shoots	Conifer shots related with Cupressaceae
Dicotyledoneae	Indeterminate	Polazzo	Isolated Leaves
Equisetites	E. sp.	Križ	Stems	Stems of Equisetales
Eucalyptus	E. sp.	Kazlje Križ	Isolated Leaves	Angiosperms leaves of Eucalypteae
Filicales	Indeterminate	Kazije	Pinnae
Frenelopsis	F. ssp.	Villaggio del Pescatore Polazzo	Isolated Branched Shoots	A Conifer, member of Hirmeriellaceae. The msot abundant foliar remain locally
Ginkgoales?	Indeterminate	Polazzo	Isolated Leaves
Magnoliaephyllum	M. sp.	Kazlje	Isolated Leaves	A Flowering Plant, suggested to belong to Magnoliaceae
Pagiophyllum	P. "sp. nov."P. ssp.	Dobravlje Kazlje Križ Polazzo	Isolated Branched Shoots	Conifer shots related with Araucariaceae or Hirmeriellaceae.
Pinophyta	Indeterminate	Dobravlje Kazlje Križ Villaggio del Pescatore	Isolated Branched Shoots	Includes at least a new genus and 2 species
Papillopollis	P. aradeaensis	Villaggio del Pescatore	Pollen	Resembles extant members of the wind-pollinated Juglandales-Myricales
Sassafras	S. sp.	Kazlje	Isolated Leaves	Angiosperms leaves of Lauraceae
Sphenolepis	cf.S. spp.	Polazzo	Isolated Cones	Conifer cones related with Cupressaceae