Deinotheriidae
Encyclopedia
Deinotheriidae is a family of prehistoric elephant-like proboscidea
ns that lived during the Tertiary period
, first appearing in Africa, then spreading across southern Asia (Indo-Pakistan) and Europe. During that time they changed very little, apart from growing much larger in size - by the late Miocene they had become the largest land animals of their time. Their most distinctive feature was the downward curving tusks on the lower jaw.
Deinotheres were not very diverse; there are only three known genera
: Chilgatherium
; Prodeinotherium
; and Deinotherium
. These form an evolutionary succession (with each new genus replacing the preceding one).
Unlike the various mammoth and mastodont lineages, the deinotheres died out in the early Pleistocene, rather than continuing through the ice age
.
and canine
teeth, but possessed five low-crowned molar
s on each side, with the same number in the lower jaw. Harris (1976) has shown that deinotheres used their front teeth for crushing their food, and the back teeth for shearing (slicing), the plant material.
The front part of the lower jaw was turned downwards, and bore the two tusk-like incisors. These curved downwards and backwards in a sort of huge hook, and constituted the most distinct feature of the deinotheres.
s, with the front teeth being used to crush the food, while the second and third molars have a strong vertical shearing action, with little lateral (side to side) movement. This chewing action differs from both that of gomphotheres (lateral grinding) and elephant
s (horizontal shearing). Deinothere molars show little wear, indicating a diet of soft, nongritty, forest
vegetation, with the down-turned lower tusks being used for stripping bark
or other vegetation.
Deinotherium giganteum has a more elongate lower forelimb than early and middle Miocene Prodeinotherium, indicating a more efficient stride as an adaptation to the spread of savanna
s in Europe during the late Miocene. Deinotheres would probably migrate from forest to forest, traversing the wide and (to them) useless grasslands.
to the Proboscidea, but this view is not followed nowadays.
from the late Oligocene
. Its fossil remains have been found in the district of Chilga
in Ethiopia
(hence the name). This indicates that, like other proboscideans, deinotheres evolved in Africa
. Chilgatherium was quite small, about midway between a large pig
and a small hippopotamus
in size.
By the early Miocene
, deinotheres had grown to the size of a small elephant, and had migrated to Eurasia
. Several species are known, all belonging to the genus Prodeinotherium.
During the late middle Miocene these modest-seized proboscideans were replaced by much larger forms across Eurasia. In Europe, Prodeinotherium bavaricum appeared in the early Miocene mammal faunal zone MN 4, but was soon replaced by Deinotherium giganteum in the middle Miocene. Likewise in Asia, Prodeinotherium is known from the early Miocene strata in the Bugti Hills, and continued into the middle Miocene Chinji Formation, where it was replaced by Deinotherium indicum.
While these Miocene deinotheres were dispersed widely and evolved to huge elephant size, they were not as common as the contemporary (but smaller) euelephantoidea. Fossil remains of this age are known from the France
, Germany
, Greece
, Malta
, and northern India
and Pakistan. These consist chiefly of teeth and the bones of the skull.
After the extinction of the indricotheres
at the end of the early Miocene, the deinotheres were (and remained) the largest animals walking the Earth.
The late Miocene was the heyday of the giant deinotheres. D. giganteum was common from Vallesian
and Turolian
localities in Europe. Prodeinotherium, which was reasonably well represented in the early Miocene of Africa, was succeeded by D. bozasi at the beginning of the late Miocene. And in Asia, Deinotherium indicum was most common in the late Miocene Dhok Pathan Formation.
Fossil teeth of D. giganteum, from the late Miocene Sinap Formation at the Turkish
site of Kayadibi are larger than those from older localities, such as Eppelsheim
, Wissberg
and Montredon
, indicating a tendency for increasing size of members of the species over time. These were the biggest animals of their day, protected from both predators and rival herbivores by virtue of their huge bulk. Not until the Pleistocene would the largest mammoth
s approach them in size.
With the end of the Miocene, deinothere fortunes declined. Deinotherium indicum died out about 7 million years ago, possibly driven to extinction by the same process of climate change that had previously eliminated the even more enormous Indricotherium. While in Europe, Deinotherium giganteum continued, albeit with dwindling numbers, until the middle Pliocene
; the most recent specimen is from Romania
.
In its original African homeland, Deinotherium continued to flourish throughout the Pliocene, and fossils have been uncovered at several of the African sites where remains of hominid
s have also been found.
The last deinothere species to become extinct was Deinotherium bozasi. The youngest known specimens are from the Kanjera Formation, Kenya
, about one million years ago (early Pleistocene
). The causes of the extinction of such a successful and long-lived animal are not known, although a small number of other species of African megafauna
also died out at this time.
Proboscidea
Proboscidea is a taxonomic order containing one living family, Elephantidae, and several extinct families. This order was first described by J. Illiger in 1881 and encompasses the trunked mammals...
ns that lived during the Tertiary period
Tertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...
, first appearing in Africa, then spreading across southern Asia (Indo-Pakistan) and Europe. During that time they changed very little, apart from growing much larger in size - by the late Miocene they had become the largest land animals of their time. Their most distinctive feature was the downward curving tusks on the lower jaw.
Deinotheres were not very diverse; there are only three known genera
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
: Chilgatherium
Chilgatherium
Chilgatherium is the earliest and most primitive representative of the family Deinotheriidae. It is known from late Oligocene fossil teeth found in the Ethiopian district of Chilga...
; Prodeinotherium
Prodeinotherium
Prodeinotherium is an early representative of the family Deinotheriidae, that lived in Africa, Europe, and Asia in the early and middle Miocene. It was the size of a small elephant, about 9 feet at the shoulders, but differed from elephants in possessing a pair of downward curving tusks on the...
; and Deinotherium
Deinotherium
Deinotherium , also called the Hoe tusker, was a large prehistoric relative of modern-day elephants that appeared in the Middle Miocene and continued until the Early Pleistocene. During that time it changed very little...
. These form an evolutionary succession (with each new genus replacing the preceding one).
Unlike the various mammoth and mastodont lineages, the deinotheres died out in the early Pleistocene, rather than continuing through the ice age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...
.
Description
The body shape and proportions of deinotheres were very much like those of modern elephants. The legs were long, like modern elephants, but the skull was rather flatter than that of true elephants. The upper jaw lacked incisorIncisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
and canine
Canine tooth
In mammalian oral anatomy, the canine teeth, also called cuspids, dogteeth, fangs, or eye teeth, are relatively long, pointed teeth...
teeth, but possessed five low-crowned molar
Molar (tooth)
Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....
s on each side, with the same number in the lower jaw. Harris (1976) has shown that deinotheres used their front teeth for crushing their food, and the back teeth for shearing (slicing), the plant material.
The front part of the lower jaw was turned downwards, and bore the two tusk-like incisors. These curved downwards and backwards in a sort of huge hook, and constituted the most distinct feature of the deinotheres.
Ecology
Harris (1975) argues that deinotheres were "shearing browsers" adapted for feeding on plants above ground level. The way they chewed their food was probably similar to that of modern tapirTapir
A Tapir is a large browsing mammal, similar in shape to a pig, with a short, prehensile snout. Tapirs inhabit jungle and forest regions of South America, Central America, and Southeast Asia. There are four species of Tapirs: the Brazilian Tapir, the Malayan Tapir, Baird's Tapir and the Mountain...
s, with the front teeth being used to crush the food, while the second and third molars have a strong vertical shearing action, with little lateral (side to side) movement. This chewing action differs from both that of gomphotheres (lateral grinding) and elephant
Elephant
Elephants are large land mammals in two extant genera of the family Elephantidae: Elephas and Loxodonta, with the third genus Mammuthus extinct...
s (horizontal shearing). Deinothere molars show little wear, indicating a diet of soft, nongritty, forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
vegetation, with the down-turned lower tusks being used for stripping bark
Bark
Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...
or other vegetation.
Deinotherium giganteum has a more elongate lower forelimb than early and middle Miocene Prodeinotherium, indicating a more efficient stride as an adaptation to the spread of savanna
Savanna
A savanna, or savannah, is a grassland ecosystem characterized by the trees being sufficiently small or widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of C4 grasses.Some...
s in Europe during the late Miocene. Deinotheres would probably migrate from forest to forest, traversing the wide and (to them) useless grasslands.
Relationships
The ancestry and evolutionary relationships of the deinotheres remain obscure. It has been suggested that they are related to the barytheres, due to similarities in the structure of the teeth. What is clear is that they diverged from the rest of the proboscideans at a very early date. In the 1970s several researchers placed them in a separate orderOrder (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
to the Proboscidea, but this view is not followed nowadays.
Evolutionary history
The oldest known deinothere is Chilgatherium harrisiChilgatherium
Chilgatherium is the earliest and most primitive representative of the family Deinotheriidae. It is known from late Oligocene fossil teeth found in the Ethiopian district of Chilga...
from the late Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
. Its fossil remains have been found in the district of Chilga
Chilga
Chilga is one of the 105 woredas in the Amhara Region of Ethiopia. It is named after its chief town Chilga , an important stopping point on the historic Gondar-Sudan trade route...
in Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...
(hence the name). This indicates that, like other proboscideans, deinotheres evolved in Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
. Chilgatherium was quite small, about midway between a large pig
Pig
A pig is any of the animals in the genus Sus, within the Suidae family of even-toed ungulates. Pigs include the domestic pig, its ancestor the wild boar, and several other wild relatives...
and a small hippopotamus
Hippopotamus
The hippopotamus , or hippo, from the ancient Greek for "river horse" , is a large, mostly herbivorous mammal in sub-Saharan Africa, and one of only two extant species in the family Hippopotamidae After the elephant and rhinoceros, the hippopotamus is the third largest land mammal and the heaviest...
in size.
By the early Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
, deinotheres had grown to the size of a small elephant, and had migrated to Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...
. Several species are known, all belonging to the genus Prodeinotherium.
During the late middle Miocene these modest-seized proboscideans were replaced by much larger forms across Eurasia. In Europe, Prodeinotherium bavaricum appeared in the early Miocene mammal faunal zone MN 4, but was soon replaced by Deinotherium giganteum in the middle Miocene. Likewise in Asia, Prodeinotherium is known from the early Miocene strata in the Bugti Hills, and continued into the middle Miocene Chinji Formation, where it was replaced by Deinotherium indicum.
While these Miocene deinotheres were dispersed widely and evolved to huge elephant size, they were not as common as the contemporary (but smaller) euelephantoidea. Fossil remains of this age are known from the France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
, Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
, Malta
Malta
Malta , officially known as the Republic of Malta , is a Southern European country consisting of an archipelago situated in the centre of the Mediterranean, south of Sicily, east of Tunisia and north of Libya, with Gibraltar to the west and Alexandria to the east.Malta covers just over in...
, and northern India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
and Pakistan. These consist chiefly of teeth and the bones of the skull.
After the extinction of the indricotheres
Indricotheriinae
Indricotheriinae is a subfamily of Hyracodontidae, a group of long-limbed, hornless rhinoceroses that evolved in the Eocene epoch and continued through to the early Miocene. The earlier hyracodontid species, such as Hyracodon were modest-sized, fast-running, lightly built animals with little...
at the end of the early Miocene, the deinotheres were (and remained) the largest animals walking the Earth.
The late Miocene was the heyday of the giant deinotheres. D. giganteum was common from Vallesian
Vallesian
The Vallesian age is a period of geologic time within the Miocene used more specifically with European Land Mammal Ages. It precedes the Turolian age and follows the Astaracian age. The Turolian overlaps the Tortonian and Messinian ages....
and Turolian
Turolian
The Turolian age is a period of geologic time within the Miocene used more specifically with European Land Mammal Ages. It precedes the Ruscinian age and follows the Vallesian age. The Turolian overlaps the Tortonian and Messinian ages....
localities in Europe. Prodeinotherium, which was reasonably well represented in the early Miocene of Africa, was succeeded by D. bozasi at the beginning of the late Miocene. And in Asia, Deinotherium indicum was most common in the late Miocene Dhok Pathan Formation.
Fossil teeth of D. giganteum, from the late Miocene Sinap Formation at the Turkish
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
site of Kayadibi are larger than those from older localities, such as Eppelsheim
Eppelsheim
Eppelsheim is an Ortsgemeinde – a municipality belonging to a Verbandsgemeinde, a kind of collective municipality – in the Alzey-Worms district in Rhineland-Palatinate, Germany.- Municipal council :...
, Wissberg
Wissberg
Wissberg is a mountain in the Urner Alps. It is located near Engelberg in Switzerland.-External links:*...
and Montredon
Montredon
Montredon is a commune in the Lot department in south-western France....
, indicating a tendency for increasing size of members of the species over time. These were the biggest animals of their day, protected from both predators and rival herbivores by virtue of their huge bulk. Not until the Pleistocene would the largest mammoth
Mammoth
A mammoth is any species of the extinct genus Mammuthus. These proboscideans are members of Elephantidae, the family of elephants and mammoths, and close relatives of modern elephants. They were often equipped with long curved tusks and, in northern species, a covering of long hair...
s approach them in size.
With the end of the Miocene, deinothere fortunes declined. Deinotherium indicum died out about 7 million years ago, possibly driven to extinction by the same process of climate change that had previously eliminated the even more enormous Indricotherium. While in Europe, Deinotherium giganteum continued, albeit with dwindling numbers, until the middle Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
; the most recent specimen is from Romania
Romania
Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...
.
In its original African homeland, Deinotherium continued to flourish throughout the Pliocene, and fossils have been uncovered at several of the African sites where remains of hominid
Hominidae
The Hominidae or include them .), as the term is used here, form a taxonomic family, including four extant genera: chimpanzees , gorillas , humans , and orangutans ....
s have also been found.
The last deinothere species to become extinct was Deinotherium bozasi. The youngest known specimens are from the Kanjera Formation, Kenya
Kenya
Kenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east...
, about one million years ago (early Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
). The causes of the extinction of such a successful and long-lived animal are not known, although a small number of other species of African megafauna
Megafauna
In terrestrial zoology, megafauna are "giant", "very large" or "large" animals. The most common thresholds used are or...
also died out at this time.