32 - Rhinoceros
Stephanorhinus hundsheimensis (Toula, 1902)
This medium-large rhinoceros stood over 200 cm tall at the shoulder and had two horns on its snout. It appeared in the late Pleistocene and spread to Central and Southern Europe, including Italy. It was a generalist rhinoceros, capable of adapting to both wooded and steppe environments, with a slight preference for the former.
It died out around 500,000 years ago due to competition from two other species of rhinos that arrived from Asia and were more specialized: Stephanorhinus kirkbergensis, or Merk’s rhinoceros, adapted to forested environments, and Stephanorhinus hemitoechus, or the steppe rhinoceros, adapted to open environments.
Coelodonta antiquitatis (Blumenbach, 1799)
During cold phases, the woolly rhinoceros was present in the Po Valley. It was covered with fur with a very thick undercoat and two horns, one of which was very long and flattened at the sides.
33 - The Ice Age: Glaciations and Interglaciations
In common parlance, the informal term “ice age” refers to the Quaternary Period or Pleistogene (Pleistocene + Holocene), when continuous climatic cooling began 2.51 million years ago and culminated in a series of glaciations (or ice ages) interspersed with warmer interglacial phases (or interglaciations). Though the best known, the Quaternary ice age was not the only one in Earth’s history, only the most recent.
An ice age stems from a general lowering of the temperature on a global scale that lasts for a very long time, so that every year the amount of snow and ice formed is greater than the amount that melts, leading to a steady expansion of glaciers and the snowline.
Given the current permanent ice fields in Greenland and Antarctica, we can say we are still in the Quaternary ice age, but more specifically in an interglacial period that corresponds to the Epoch in which we live (Holocene).
The alternation of climatic conditions, with glacial and interglacial periods, of an ice age is matched by advancing and retreating glaciers, fluctuations in sea levels – which rise when ice and snow melt and fall when they are being formed – and produces changes in the composition of the flora and fauna.
The causes of global climate cooling characteristic of the ice ages, as well as the alternation of glacial and interglacial periods within them, have been identified with a number of factors that interact with and influence each other, such as:
- astronomical phenomena that periodically alter the characteristics of the Earth’s rotation around the Sun and on its own axis (Milankovitch cycles)
- composition of the atmosphere, with variations in the amounts of greenhouse gases such as carbon dioxide and methane
- plate tectonics: by causing phenomena such as volcanism and orogeny and defining the extent and arrangement of the continental masses, this affects the movement of masses of air and ocean currents.
34 - EQUIDS
The equids evolved primarily in North America during the Eocene, though on several occasions some genera migrated, evolved and become extinct in other parts of the world. The horses present in Eurasia represent four morphologically distinct species: Prezewalski’s horse (Equus prezewalskii) in Mongolia, the tarpan (Equus ferus), in central Russia and Ukraine (exterminated in the wild state in the nineteenth century), the domestic horse (Equus caballus), probably derived from the tarpan, and finally the donkey (Equus asinus). The remains of the earliest horses with a morphology similar to today’s horses come from Middle Pleistocene sediments. The domestic form appears in the fossil record about 5,500 years ago (Dereivka, Ukraine). Equus hydruntinus, similar to the donkey but more finely built, was quite common in southern Italy in the Middle and Upper Pleistocene.
35 - Era Glaciale or Ice Age?
In Italian people commonly speak of the Era Glaciale or “Ice Era”, but it would be more correct to speak of an “Ice Age”. The actual duration of the glacial and interglacial phases with respect to the (geochronological) time scale used by scientists comes close to that of an Age – and certainly not to that of the Eras, which are far greater!
The Ages are time intervals into which the Epochs are divided, being in turn subdivisions of Periods, which are contained in Eras. From this point of view, the English terminology Glacial Age or Ice Age is more appropriate.
Though of relatively short duration, the Pleistocene glaciations remained a major event on a global scale in the history of the planet. In this regard, in 2009 the ICS (International Commission on Stratigraphy) decided to transfer the Age known as the Gelasian from the Pliocene Epoch to the Pleistocene: by doing so, the beginning of the Ice Age, dated to 2.588 million years ago, not only coincided with the beginning of an Age, but also with that of an Epoch (the Pleistocene) and a Period (the Pleistogene or Quaternary).
36 – CERVIDS: The Irish Elk
Irish Elk Megaloceros giganteus (Blumenbach, 1803)
Also known as the giant elk of the peat bogs or Irish Elk, this herbivore could stand 180 cm tall at the shoulder and its huge antlers were sometimes over 300 cm wide. Coming from China, it appeared in Europe during the Middle Pleistocene, sharing the wetlands and taiga with bison, mammoths and horses. Its extinction in the Po Valley seems to have occurred at the end of the last Ice Age, coinciding with the spread of closed forest at the expense of the vast grasslands. Prehistoric man actively hunted it, perhaps driving it into the tangled vegetation where its huge antlers hampered its movements.
37 – Carnivores
The fossil remains of the predators at the top of the food chain, such as wolves, lions, foxes, hyenas and some species of bears are much rarer than those of their prey. This reflects what happens in nature, where carnivores are much less numerous than herbivores and their remains are therefore much less likely to fossilize.
38 – BOVIDAE: The Bison
Appearing in the early Miocene, the bovids underwent an explosive adaptive radiation in the Late Miocene. In the Pleistocene forms very similar to today’s bison and cattle were found in Europe.
Steppe Bison Bison priscus (Bojanus, 1827)
This is one of the commonest species in fossil deposits in the Po Valley. It appeared in Europe during the Middle Pleistocene, coming from the East. It occupied the cold, arid steppes during the last Wurmian glacial phase, together with the woolly mammoth. Its height at the shoulders approached 200 cm and the arcs of the great horns with swept back tips could be up to 120 cm wide. This species gave rise to the current European form, Bison bonasus, which still survives in the wild in protected areas of Poland and Belarus.
39 - BOVIDS: Cattle
Aurochs (primeval cattle) Bos primigenius (Bojanus, 1827)
This was the wild form of today’s domestic cattle. Compared to the latter the aurochs had a more massive structure, even heftier than the bison’s. Its sexual dimorphism was strongly marked, large females being only two-thirds the size of males. Appearing in the early Middle Pleistocene, it reached its greatest size (220 cm at the shoulder) in the Holocene. It was most widespread when the forested areas opened out into large glades, while it retreated into more sheltered areas with a Mediterranean climate during the coldest intervals. This large herbivore finally died out in the seventeenth century because of hunting by humans and competition with domesticated forms: the last recorded specimen died in Lithuania in 1628.
40 - CERVIDS: Deer and Elk
Red deer Cervus elaphus (Linnaeus, 1758)
The current form of deer has been present in Europe since the second half of the Middle Pleistocene. In Italy it has survived since then in some areas of the Alps, while it has been reintroduced to the Apennines. It lives mainly near clearings in forests of conifers and deciduous trees. It stands up to 150 cm high at the shoulder.
Elk Alces alces (Linnaeus, 1758)
This is the same species still found in Northern Europe. It has been conjectured that it became differentiated from the extinct form Alces latifrons in the Middle Pleistocene. It lives near swamps or watercourses in open birch or pine forests. In Italy fossils have been reported in the Po Valley and Liguria, while it seems that never to have spread to the south.
Broad-Fronted Moose Alces latifrons (Johnson, 1874)
This differed from the present species by its much longer beams (the main stems of the antlers). In Europe fossils are very common, but rare in Italy, where they have been reported only at Ranica (BG) and near Voghera, along the Pavian stretch of the Po. They appeared in the Pleistocene and became extinct after the last interglacial phase. They lived in more open environments than those favoured by Alces alces.
41 - URSIDS
The origin of the family Ursidae, which appeared relatively recently, dates from at the beginning of the Miocene. Beginning with archaic forms about the size of a fox, the general trend has been an increase in size and adaptation of the teeth to an omnivorous or even herbivorous diet. The genus Ursus appeared in the Pliocene, with the species U. minimus.
Deninger’s Bear Ursus deningeri (von Reichenau, 1904)
Characteristic of the post-Villafranchian faunas of the Early and Middle Pleistocene, this creature was about the same size as the modern brown bear. Its remains are frequent in Palaeolithic deposits and show that it was hunted by human populations.
Cave Bear Ursus spelaeus (Rosenmuller and Heinroth, 1794)
This is the largest ursid to be found in Europe and the commonest in the fossil record (the Dragon Cave in Austria alone yielded 30,000 specimens). It was very common in northern and central Italy until the woodlands shrank and turned to steppe. It probably originated from U. deningeri, which became extinct between the Pleistocene and Holocene. It was mainly herbivorous and the males were much larger than the females.
Brown Bear Ursus arctos (Linnaeus, 1758)
The brown bear, an omnivore, originated in China in the Middle Pleistocene, but later spread to Europe, where it co-existed with the cave bears but unlike them did not become extinct. Today it is among the species in danger of extinction due to the drastic depletion of its environment, caused by humans, who have decimated the surviving specimens.
42 - Hippopotami and Suids
Hippopotamus amphibius (Linnaeus, 1758)
Clearly differentiated in Africa as early as the Pliocene, during the Pleistocene the hippopotami made many migrations as a function of climate change, travelling as far as England during the interglacial intervals with warm climates. Fossil remains are found in the Po Valley from the Middle Pleistocene to the early stages of the last glacial interval (Wurm). Most scholars hold this was the same species that currently lives in Africa, up to 165 cm high at the shoulder. A herbivore, the hippo spends most of its time in pools of water.
Sus scrofa (Linnaeus, 1758)
The wild boar, an omnivore, spread all through the Middle Pleistocene and is still present in many regions of Asia and Europe, including Italy. Fossil forms were slightly larger than those found today, but like these, they lived in small herds in the rich underbrush of forest environments in areas with a temperate climate.
43 - Proboscideans
Alluvial deposits in the Po Valley have been found to contain bones belonging to at least four different species of proboscideans, three to the genus Mammuthus and one to Elephas. The three species of mammoth discovered derive one from another and they all originated in Asia, from the lower Pleistocene, arriving later in Europe. In Italy, Mammuthus meridionalis has been reported from 2 million to 700,000 years ago, Mammuthus trogontherii from 700,000 to 200,000 years ago, and Mammuthus primigenius from 200,000 to about 20,000 years ago. Elephas antiquus also arrived in Europe from Asia, and remained here until 40,000 years ago. It is important to remember that the proboscideans originated in Africa, from where they subsequently migrated to Asia and other continents.
Elephas antiquus (Falconer & Coutley, 1847)
Up to 4 m tall at the shoulder, this large herbivore had long tusks that were only slightly arched and closely resembled today’s African elephant in appearance. It appeared in Western Europe in the Early Pleistocene and its remains are more common in deposits relating to periods when the climate was temperate. In central Italy this species was present when the horse and aurochs became the dominant forms. It also spread to the north during interglacials.
Elephas meridionalis (Nesti, 1825)
This mammoth appeared in the Pleistocene and was associated with cold to temperate climates. The earliest forms were smaller forest-dwellers, but they soon gave rise to giants 4 m high at the shoulder living in more open environments. In appearance it was much like the Indian elephant, with curved, divergent tusks.
Mammuthus primigenius (Blumenbach, 1799)
This is one of the best-known extinct creatures, because of the notable finds of complete frozen specimens, mainly in Siberia. The remains found in the Po Valley consist rather of individual disarticulated bones, due largely to the action of the currents of the Po and its tributaries, which have scattered the various skeletal parts along their course.
The males of this species could stand higher than 3 m at the shoulder; the females were smaller. Both sexes, however, had long curved tusks, perhaps used for scraping away snow and digging up plants. The woolly mammoth was closely tied to cold, arid steppe environments and disappeared after the last glacial period, in part because of hunting by humans. The meat of these pachyderms was one of the principal food sources for humans of the Palaeolithic in central and northern Europe. The non-edible parts of its body were also used for making tools, garments, decorative items and building materials.