Monday, 9 March 2020


In the summer of 1996, Angelo Zanella, an avocational fossil collector and active collaborator at the Museo di Storia Naturale di Milano (MSNM) spotted some intriguing fossil bone sticking out of a large block of rock while hunting for ammonites in the Salnova marble quarry.

The quarry is in the Alpine foothills, at the Swiss–Italian border near Saltrio. Saltrio is about 80 km north of Milan in the province of Varese, Lombardy, Italy.

Zanella reported the bones to the MSNM, which arranged a paleontological expedition to the site. The research was difficult because the explosives used for industrial quarrying had blown up the fossil-bearing layer and had broken it into hundreds of pieces.

The Saltrio quarry has been active since the 15th century as one of the finest sites of marble production, and the “Saltrio Stone” provides high-quality building materials for many famous Italian monuments  — the Scala Opera House in Milan and the Mole Antonelliana in Turin. They actively use dynamite to extract the marble. Great for the workers who are not required to manually break-up the massive pieces. Less so for the fossils. The bones from the Saltrio theropod were blown to bits just prior to Zanella's discovery then had to be pieced back together.

Three years later, after 1,800 h of chemical preparation in the Laboratory of the MSNM, 132 remains were extracted from three main blocks. Although fragmentary, jaw fragments, one tooth, rib remains, pectoral and limb bones were analyzed and found to be that of a large theropod dinosaur.

The Saltrio theropod (MSNM V3664) became popular by the name, Saltriosauro, and so it was reported (Dal Sasso, 2001a) and preliminarily described (Dal Sasso, 2001b, 2004).

Pictured above: selected elements used in the diagnosis of Saltriovenator zanellai n. gen. n. sp. Right humerus in medial (A), frontal (B) and distal (C) views; (D) left scapula, medial view; (E) right scapular glenoid and coracoid, lateral view; (F) furcula, ventral view; tooth, labial (G) and apical (H) views; (I) left humerus, medial view; right second metacarpal in dorsal (J), lateral (L) and distal (N) views; first phalanx of the right second digit in dorsal (K), lateral (M) and proximal (O) views; (P–T) right third digit in proximal, dorsal and lateral views; (U) right distal tarsal IV, proximal view; third right metatarsal in proximal (V) and frontal (X) views; second right metatarsal, proximal (W) and frontal (Y) views; (Z) reconstructed skeleton showing identified elements (red). Abbreviations as in text, asterisks mark autapomorphic traits. Scale bars: 10 cm in (A)–(E), (I), and (U)–(Y); two cm in (F), and (J)–(T); one cm in (G).

Photos by G. Bindellini, C. Dal Sasso and M. Zilioli; drawing by M. Auditore. -