The story opens following the discovery, from 1972 to 1994, of a series of fossil impressions casually found in the exposed layers at the foot of Mt. Catria. These impressions were very interesting first because they represented an undocumented find for scientific literature, and second because they did not belong to any living species. A regular series of impressions is called a “trail” and the study of the latter makes it possible to collect important information for the reconstruction of the "author" of the impressions, for example its gait, the form of its feet, its posture, its skeletal structure, it speed of movement, its weight. Thus, from a trail, the correct systemic position, the dimensions, the general morphology and, at times, the diet of the "author" can be reconstructed. The impressions left by Ugo, a trail consisting in about twenty sets, distributed with a certain regularity, are divided into two morphologically different types: the large ones, with a shape similar to that of a pear are aligned in two series; the other, smaller ones are arranged to form a long zigzag line. The cast displayed at the museum, is an excellent demonstration of the find.

The environment in which Ugo lived was marine; the impressions were made on the bottom of sea estimated to be several tens of meters in depth (20 – 30 meters in depth..) Another condition necessary for the formation of the casts found was that of having a bottom constituted of material with plastic characteristics for the conservation of the impressions against the currents and the movement of the waters. The fact that Ugo swam and the direction in which he swam, has been reconstructed by observing the expulsion edge, present only behind the impressions and not all around them: Ugo did not walk on the bottom, weighting his limbs, rather he used them to push himself in a swimming motion.

And he used the front limbs for thrust (the large prints) while he left his rear limbs light and extended (the smaller impressions lying over the first), perhaps for a braking effect or for direction. The form and distribution of the impressions identify a vertebrate animal with four feet which moved snakelike as he moved around on the sea bottom in search of food.

Therefore, Ugo was a reptile from the Mesozoic era. He lived in aquatic environments and has provided important information on the depth and nature of the sea bottom, useful in the reconstruction of the palaeogeography of the area which, in the Jurassic era, counted on various marine environments of divers depths and on rocks almost completely lacking in any reptile fossils.