This canid is very important because it signals the advent of the so-called "wolf-event", that is the modification of the groups of European carnivores which occurred about 2.5-2.4 million years ago following the onset of climatic changes typical of the Quaternary, characterized by fluctuations of temperature and progressive increase of aridity during the colder phases. This involves the arrival in Europe of representatives of the genus Canis: Canis etruscus is in fact the oldest representative of these animals. It reached dimensions comparable to that of a current wolf, it may be that it was a social animal like the latter and therefore that it hunted in packs. Among the favorite prey of the canids of the time are the "false" fallow deer of Nesti and the deer with comb-shaped antlers.

Within the lower Pleistocene ecosystem of the upper Valdarno, it is one of the most impressive predators. It belongs to the Homoterium category and falls into the subfamily which also includes the more famous Smilodon category. It had a "hanging" appearance, similar to that of a hyena, because the forelimbs were longer than the hind ones. The skull was strong and equipped with strong, rather long canines. Various species of this animal are known, including the European crenatidens.

The Etruscan bear was an Ursidae widespread in Europe in the lower Pleistocene, believed in the past to be the basis of the group of European and American brown bears. The specimens from the early Pleistocene were small in size and rather similar to the modern Tibetan bear, which weighs up to 200 kg. On the contrary, the specimens that lived at the end of the lower Pleistocene reached the size of a current brown bear. It was an opportunistic species, which colonized a great variety of environments, although it was probably adapted for woodland environments. In fact, its diet was omnivorous and included a variety of plants and animals, including fish. The Etruscan bear became extinct at the end of the lower Pleistocene, when it was replaced by the ancestors of the modern brown bear, coming from Asia.

The Auvergne bear was a species of bear widespread, during the entire Pliocene, in Europe and China with various subspecies. It was a small Ursidae typical of forest environments, similar to the current Tibetan bear, especially from the dental point of view, although it was smaller in size. The Auvergne bear was the first representative of the genus Ursus and in fact is the origin of black, cave and brown bears both in Europe and in North America. In Europe it gives origin, at the end of the Pliocene (about 2.6 million years ago), to the Etruscan bear.

This large hippopotamus is a late representative of the characteristic faunas of the age known as the upper Villafranchiano of the upper Valdarno (dating back to about 2-1.5 million years ago), when the landscape was characterized by open forest environments alternating with savannah environments, in following the drying up and lowering of temperatures at the beginning of the Pleistocene (about 2.6 million years ago). Like the current hippos, it was a large partially aquatic herbivore, whose males were endowed with particularly long tusks, used for defense and for fighting for the territory. It is possible that the ancient hippopotamus even survived up to about 126,000 years ago, at the beginning of the Upper Pleistocene, although the last fossils certainly belonging to this species date back to about 500,000 years ago.

This large animal is one of the five species of extinct proboscideans that can be found in the upper Valdarno. Belonging to the Elephantidae family, it comes from Africa and is a distant ancestor of the famous woolly mammoth. It was a large animal that in some subspecies could reach a height of around 4 m and a weight of around 11 t, comparable to that of the largest known African savannah elephant. The molars of the southern elephant signal the climatic variations of the Valdarno, which passed from a more humid and warm climate, with a landscape mainly characterized by forest environments, to a more arid one with more open spaces. Mammuthus meridionalis was in fact a herbivore with a varied diet and ate both leaves and bark of trees and low plants and grass, unlike more ancient proboscidia such as the Auvergne mastodon and the Borson mastodon.

The late Pliocene rhinoceros lived at the end of the Pliocene. It was a relatively slender animal, medium to large in size compared to other contemporary rhinos. It lived in the same faunas together with other animals, such as the Auvergne tapir, the Auvergne mastodon and the Borson mastodon, testifying to the existence of the so-called Triversa Fauna Unit. This association testifies to a forest environment with a warm and humid climate, also reflected by the set of teeth with low dental crown, typical of a grinder adapted to a diet composed mostly of leaves, roots and bark.

The auroch was the ancestor of modern domestic cows: it probably originated in India between 2 and 1.8 million years ago, at the beginning of the second half of the lower Pleistocene, while the first known remains in Europe date back to the beginning of the Pleistocene. medium (about 800,000 years ago). It was distinguished from domesticated cattle mainly by the size and shape of the horns: it could in fact reach 1.80 meters at the withers; moreover, the horns of the auroch were relatively robust and with a characteristic lyre shape, directed forward with the tip curved upwards, as well as being very long. In winter the aurochs gathered in large herds, while in summer there were herds of only cows with their newborn babies, with the males living separated from them in small groups or individually. They lived mainly in the more open areas of marshy environments and humid forests, where they grazed.

The steppe bison is representative of the climate change underway during the Pleistocene, which leads to a progressive cooling and drying of the environment that culminates in the so-called ice ages. This animal, found in the upper Valdarno from the end of the middle Pleistocene, originated in southern Asia around the middle of the lower Pleistocene. Similar to today's bison, it was up to 2m tall at the shoulder and reached an estimated weight of between 700 and 800kg, with horns up to 0.5m long. The presence of a thicker coat than today's bison indicates an animal adapted to colder climates; moreover, it fed mainly on herbaceous plants in a steppe environment. This animal became extinct, like many other faunas typical of the glacial periods, at the end of the Pleistocene in Europe and Asia and slightly later in North America, being replaced by the current cattle species.

This Equidae is part of the faunas of the so-called "Third Phase" of the Valdarno, which took place between the end of the Middle Pleistocene and the beginning of the Upper Pleistocene (approximately between 300,000 and 100,000 years ago), in which there is a progressive cooling and drying of the environment, with the formation of wide open steppe spaces and the arrival of faunas that testify to these changes. It is likely that the latter originated in North America at the beginning of the Calabrian (about 1.8 million years ago), and then subsequently immigrated to the Far East via the Bering Strait.