Pygmy elephant

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Pygmy elephant
Borneo-elephant-PLoS Biology.jpg
The Borneo pygmy elephant (Elephas maximus borneensis)
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Class:
Mammalia
Superorder:
Afrotheria
Order:
Proboscidea
Family:
Elephantidae

Gray, 1821

Pygmy elephants live in both Africa [1] and Asia. [2] [3] [4] The African pygmy elephant, formerly described as "Loxodonta pumilio", is currently considered to be a tiny morph of the African forest elephant (L. cyclotis). [1] The Borneo elephant (Elephas maximus borneensis), a well-documented variety of elephant, is also called "pygmy elephant." This elephant, inhabiting tropical rainforest in north Borneo (east Sabah and extreme north Kalimantan), was long thought to be identical to the Asian elephant and descended from a captive population. In 2003, DNA comparison revealed them to be probably a new subspecies. [2] [3] [4]

Africa The second largest and second most-populous continent, mostly in the Northern and Eastern Hemispheres

Africa is the world's second largest and second most-populous continent. At about 30.3 million km2 including adjacent islands, it covers 6% of Earth's total surface area and 20% of its land area. With 1.2 billion people as of 2016, it accounts for about 16% of the world's human population. The continent is surrounded by the Mediterranean Sea to the north, the Isthmus of Suez and the Red Sea to the northeast, the Indian Ocean to the southeast and the Atlantic Ocean to the west. The continent includes Madagascar and various archipelagos. It contains 54 fully recognised sovereign states (countries), nine territories and two de facto independent states with limited or no recognition. The majority of the continent and its countries are in the Northern Hemisphere, with a substantial portion and number of countries in the Southern Hemisphere.

Asia Earths largest and most populous continent, located primarily in the Eastern and Northern Hemispheres

Asia is Earth's largest and most populous continent, located primarily in the Eastern and Northern Hemispheres. It shares the continental landmass of Eurasia with the continent of Europe and the continental landmass of Afro-Eurasia with both Europe and Africa. Asia covers an area of 44,579,000 square kilometres (17,212,000 sq mi), about 30% of Earth's total land area and 8.7% of the Earth's total surface area. The continent, which has long been home to the majority of the human population, was the site of many of the first civilizations. Asia is notable for not only its overall large size and population, but also dense and large settlements, as well as vast barely populated regions. Its 4.5 billion people constitute roughly 60% of the world's population.

African forest elephant The third largest living land animal in the world

The African forest elephant is an African elephant species native to humid forests in West Africa and the Congo Basin. It is the smallest of the three living elephant species, reaching a shoulder height of 2.4 m. Both sexes have straight, downpointing tusks, which erupt when they are 1–3 years old. It lives in family groups of up to 20 individuals. Since it forages on leaves, seeds, fruit, and tree bark, it has been referred to as the 'megagardener of the forest'. It contributes significantly to maintain the composition and structure of the Guinean Forests of West Africa and the Congolese rainforests.

Contents

The term pygmy elephant should not be confused with "dwarf elephant", which is used for a number of extinct species of elephants that evolved their size due to island dwarfing.

Dwarf elephant Prehistoric elephant species

Dwarf elephants are prehistoric members of the order Proboscidea which, through the process of allopatric speciation on islands, evolved much smaller body sizes in comparison with their immediate ancestors. Dwarf elephants are an example of insular dwarfism, the phenomenon whereby large terrestrial vertebrates that colonize islands evolve dwarf forms, a phenomenon attributed to adaptation to resource-poor environments and selection for early maturation and reproduction. Some modern populations of Asian elephants have also undergone size reduction on islands to a lesser degree, resulting in populations of pygmy elephants.

Extinction Termination of a taxon by the death of the last member

In biology, extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" after a period of apparent absence.

Evolution change in the heritable characteristics of biological populations over successive generations

Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes that are passed on from parent to offspring during reproduction. Different characteristics tend to exist within any given population as a result of mutation, genetic recombination and other sources of genetic variation. Evolution occurs when evolutionary processes such as natural selection and genetic drift act on this variation, resulting in certain characteristics becoming more common or rare within a population. It is this process of evolution that has given rise to biodiversity at every level of biological organisation, including the levels of species, individual organisms and molecules.

Background

Pygmy elephants inhabited the islands from the Mediterranean region during the Pleistocene period but became extinct in the course of the Holocene. Despite striking distinctive anatomical characteristics related to insularity, some similarities with the lineage of extant Asian elephants have suggested that pygmy elephants could be most probably seen as members of the genus Elephas. Poulakakis et al. (2006) have recently challenged this view by recovering a short mtDNA sequence from an 800 000 year old fossil of the Cretan pygmy elephant (Elephas creticus). [5]

See also

Related Research Articles

Elephant Large terrestrial mammals with trunks from Africa and Asia

Elephants are mammals of the family Elephantidae and the largest existing land animals. Three species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. Elephantidae is the only surviving family of the order Proboscidea; extinct members include the mastodons. The family Elephantidae also contains several now-extinct groups, including the mammoths and straight-tusked elephants. African elephants have larger ears and concave backs, whereas Asian elephants have smaller ears, and convex or level backs. Distinctive features of all elephants include a long trunk, tusks, large ear flaps, massive legs, and tough but sensitive skin. The trunk, also called a proboscis, is used for breathing, bringing food and water to the mouth, and grasping objects. Tusks, which are derived from the incisor teeth, serve both as weapons and as tools for moving objects and digging. The large ear flaps assist in maintaining a constant body temperature as well as in communication. The pillar-like legs carry their great weight.

Elephantidae family of mammals

The Elephantidae are a family of large, herbivorous mammals collectively called elephants and mammoths. These are terrestrial large mammals with a snout modified into a trunk and teeth modified into tusks. Most genera and species in the family are extinct. Only two genera, Loxodonta and Elephas, are living.

Asian elephant species of mammal

The Asian elephant, also called Asiatic elephant, is the only living species of the genus Elephas and is distributed throughout the Indian subcontinent and Southeast Asia, from India in the west, Nepal in the north, Sumatra in the south, and to Borneo in the east. Three subspecies are recognised—E. m. maximus from Sri Lanka, E. m. indicus from mainland Asia and E. m. sumatranus from the island of Sumatra.

<i>Elephas</i> genus of mammals

Elephas is one of two surviving genera in the family of elephants, Elephantidae, with one surviving species, the Asian elephant, Elephas maximus.

<i>Palaeoloxodon</i> genus of mammals (fossil)

Palaeoloxodon is an extinct genus that contains the various species of straight-tusked elephants. Its species' remains have been found in Bilzingsleben, Germany; Cyprus; Japan; India; Sicily; Malta; and England during the excavation of the second Channel Tunnel. The English discovery, in 2006 in northwest Kent, dated to around 400,000 years ago, and was of a single adult; associated with it were Palaeolithic stone butchering tools of the type used by Homo heidelbergensis. One species, Palaeoloxodon namadicus, was possibly the largest known land mammal.

Battle of Raphia battle

The Battle of Raphia, also known as the Battle of Gaza, was a battle fought on 22 June 217 BC near modern Rafah between the forces of Ptolemy IV Philopator, king and pharaoh of Ptolemaic Egypt and Antiochus III the Great of the Seleucid Empire during the Syrian Wars. It was one of the largest battles of the Hellenistic kingdoms and was one of the largest battles of the ancient world. The battle was waged to determine the sovereignty of Coele Syria.

African elephant genus of mammals

The African elephant (Loxodonta) is a genus comprising two living elephant species, the African bush elephant and the smaller African forest elephant. Both are herbivores and live in groups. They have grey skin and differ in the size of their ears and tusks, and in the shape and size of their skulls.

Sumatran elephant subspecies of mammal

The Sumatran elephant is one of three recognized subspecies of the Asian elephant, and native to the Indonesia island of Sumatra. In 2011, IUCN upgraded the conservation status of the Sumatran elephant from endangered to critically endangered in its Red List as the population had declined by at least 80% during the past three generations, estimated to be about 75 years. The subspecies is preeminently threatened by habitat loss, degradation and fragmentation, and poaching; over 69% of potential elephant habitat has been lost within the last 25 years. Much of the remaining forest cover is in blocks smaller than 250 km2 (97 sq mi), which are too small to contain viable elephant populations.

Sri Lankan elephant Subspecies of the Asian elephant

The Sri Lankan elephant is one of three recognised subspecies of the Asian elephant, and native to Sri Lanka. Since 1986, Elephas maximus has been listed as endangered by IUCN as the population has declined by at least 50% over the last three generations, estimated to be 60–75 years. The species is primarily threatened by habitat loss, degradation and fragmentation.

Motty was the only proven hybrid between an Asian and an African elephant. He was named after George Mottershead, who founded the Chester Zoo in 1931. The male calf was born on 11 July 1978 in Chester Zoo, to Asian mother Sheba and African father Jumbolino.

Borneo elephant subspecies of mammal

The Borneo elephant, also called the Borneo pygmy elephant, is a subspecies of Asian elephant that inhabits northeastern Borneo, in Indonesia and Malaysia. Its origin remains the subject of debate. A definitive subspecific classification as Elephas maximus borneensis awaits a detailed range-wide morphometric and genetic study. Since 1986, Elephas maximus has been listed as Endangered on the IUCN Red List as the population has declined by at least 50% over the last three generations, estimated to be 60–75 years. The species is pre-eminently threatened by habitat loss, degradation and fragmentation.

Mammuthus lamarmorai is a species of mammoth which lived during the late Middle and Upper Pleistocene on the island of Sardinia. M. lamarmorai is a dwarf species, as it is estimated to have reached a shoulder height of only 1.4 m and weighed about 550 kg. This pygmy mammoth has been found mostly in the fine-grained sediments of the western part of the island.

Cyprus dwarf hippopotamus species of mammal (fossil)

The Cyprus dwarf hippopotamus or Cypriot pygmy hippopotamus is an extinct species of hippopotamus that inhabited the island of Cyprus until the early Holocene.

North African elephant subspecies of mammal

The North African elephant was a subspecies of the African bush elephant, or possibly a separate elephant species, that existed in North Africa, north of the Sahara, until becoming extinct in Roman times. These were the famous war elephants used by Carthage in the Punic Wars, their conflict with the Roman Republic. Although the subspecies has been formally described, it has not been widely recognized by taxonomists. Other names for this animal include the "North African forest elephant", "Carthaginian elephant", and "Atlas elephant". Originally, its natural range probably extended across North Africa and down to the present Sudanese and Eritrean coasts.

Cyprus dwarf elephant species of mammal (fossil)

The Cyprus dwarf elephant is an extinct species that inhabited the island of Cyprus during the Pleistocene until around 11,000 years BC. Remains comprise 44 molars, found in the north of the island, seven molars discovered in the south-east, a single measurable femur and a single tusk among very sparse additional bone and tusk fragments. The molars support derivation from the Straight-tusked elephant (Palaeoloxodon antiquus), that inhabited Europe since 780,000 years ago, who reached the island presumably during a Pleistocene glacial maximum when low sea levels opened terrestrial corridors between Cyprus and Asia Minor. During subsequent periods of isolation the population adapted within the evolutionary mechanisms of insular dwarfism, which the available sequence of molar fossils confirms to a certain extent. The fully developed Palaeoloxodon cypriotes weighed not more than 200 kg (440 lb) and had a maximum height of 1.40 m (4.59 ft). Whether the species extinction is to be attributed to the arrival of humans on the island remains debated. The species represented a sizable food source, but was easily overcome by contemporary hunter-gatherer populations.

African bush elephant Species of mammal

The African bush elephant, also known as the African savanna elephant, is the largest living terrestrial animal with bulls reaching a shoulder height of up to 3.96 m (13.0 ft). Both sexes have tusks, which erupt when they are 1–3 years old and grow throughout life.

<i>Mammuthus creticus</i> species of mammal (fossil)

Mammuthus creticus, or the Cretan dwarf mammoth, is an extinct species of dwarf mammoth. With a shoulder height of about 1 m and a weight of about 310 kg, it was the smallest mammoth that ever existed.

References

  1. 1 2 Debruyne R, Van Holt A, Barriel V, Tassy P (July 2003). "Status of the so-called African pygmy elephant (Loxodonta pumilio (NOACK 1906)): phylogeny of cytochrome b and mitochondrial control region sequences". Comptes Rendus Biologies. 326 (7): 687–97. doi:10.1016/S1631-0691(03)00158-6. PMID   14556388.
  2. 1 2 Fernando P, Vidya TN, Payne J, Stuewe M, Davison G, et al. (2003). "DNA Analysis Indicates That Asian Elephants Are Native to Borneo and Are Therefore a High Priority for Conservation". PLoS Biol. 1 (1): e6. doi:10.1371/journal.pbio.0000006. PMC   176546 . PMID   12929206.
  3. 1 2 CBS News. July 1, 2005 Spying on the Pygmy Elephant
  4. 1 2 Alfred, R.; Ahmad, A.H.; Payne, J., William, C.; Ambu, L. (2010). "Density and population estimation of the Bornean elephants (Elephas maximus borneensis) in Sabah" (PDF). Online Journal of Biological Sciences. 10 (2): 92–102. doi:10.3844/ojbsci.2010.92.102.
  5. ↑ Orlando, Ludovic; Pagés, Marie; Calvignac, Sébastien; Hughes, Sandrine; Hänni, Catherine (2007-02-22). "Does the 43 bp sequence from an 800 000 year old Cretan dwarf elephantid really rewrite the textbook on mammoths?". Biology Letters. 3 (1): 58–60. doi:10.1098/rsbl.2006.0536. ISSN   1744-9561. PMC   2373798 . PMID   17443966.
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