Elephants have evolved over 55 million years from small fox-sized ancestors like Moeritherium. Key changes along the evolutionary line include an increase in size, lengthening of the jaw and nose to form a trunk, shortening of teeth, and development of tusks. The last common ancestor of modern elephants lived over 20 million years ago. Today there are two surviving genera - Loxodonta, which includes the African bush and forest elephants, and Elephas, which includes the Asian elephant. Hunting and climate change have contributed to the extinction of other proboscidean genera such as mastodons and mammoths.

1. PRESENTED BY:
GROUP-D
SHYAMOL CHARAIMURIA
QUEEN CHETIA
KUKI MONJORI BORUAH
WAZBIR AHMED
MARINA CHORAI
ASSAM UNIVERSITY, SILCHAR
DEPARTMENT OF EARTH SCIENCE
EVOLUTION OF ELEPHANTS

2.  INTRODUCTION
 LINE OF EVOLUTION
 GENUS Moeritherium
 GENUS Berytherium
 GENUS Phiomia
 GENUS Paleomestodont
 GENUS Dinotherium
 GENUS Mastodon
 GENUS Elephas
 GENUS Loxodonta
 PHYLOGENY
 CONCLUSION
 REFFERENCE

3.  Elephants belong to the order
PROBOSCID within the class Mammalia.
 Elephants distantly present communicate
via infrasound.
 Elephants are commonly found in
AFRICA and ASIA.
 All the existing and extinct from a
common ancestor- MOERITHERES.
 Elephants have plantigrade posture
 56 million years ago, elephant species
originated in AFRICA and In 20 Mya
elephant ancestors spreads across
AFRICA to EUROPE to ASIA.

4. KINGDOM: Animalia
PHYLLUM: Chordata
CLASS: Mammalia
ORDER: Proboscidea

5.  At present, they are represented by only two genera each with a
single species-
AFRICAN - Loxodonta africanus
ASIATIC - Elephas maximus
 Fossil evidences have prove that various types of elephants, some
exhibiting
 Gigantic forms inhabited the world quite abundantly at least during
middle and upper part of Cenozoic Era.
 Unfortunately, all but two, failed to cross the Pleistocene – Holocene
boundary.
 The Proboscidea had branched into four principal stocks- the
Moeritheres, the Dinotheres, the Mastodons and the Elephants.

6. GENUS MOERITHERIUM
• Upper Eocene and Lower Oligocene times was
taper sized.
• About size of pig.
• Bunodont dentition and Swamp dweller.
• Elongated body and short legs.
• Earliest and most primitive proboscidean.
• Fossils of this genus are recorded from Bugti
beds of Baluchistan, Lower Siwalik of India and
Egypt.
GENUS BERYTHERIUM
• Eocene rocks of Egypt was similar to
Moeritherium except the difference in the jaw.
• The Proboscideans developed along several
adaptive radiations through middle and late
Cenozoic times.
• The lines of evolution were development of
giant size, pillar-like limbs and short, broad and
padded feet, secondary shortening of the lower
jaw and elongation of upper lip into
muscular,mobile trunk-proboscis.

7. • Oligocene period.
• Phiomia was around 2.5 metres(8.2 ft)
high.
• The shape of its nasal bones and very
short trunk.
• Tusk present in both jaws and skull
large with air cells.
• Some evolutionists believed it to be in
main line of evolution while others
considered it in side line evolution

8. • Extinct genus.
• Ancestors of mastodons.
• Lived in semi aquatic
swamps.
• Middle late Eocene to Early
Oligocene.
• Proboscis short.
• Upper tusk more long.
• Lower tusks are short.

9. GENUS MASTODON
• They appeared in Oligocene and continued
into Pleistocene.
• All the four tusked Mastodon with elongated
lower jaw are known as Tetrabeladon and
they had skull with forwardly sloping frontal
area. Inferior incisors were smaller than the
superior ones.
• They are reported from Lower and Mid
Siwalik rocks of India, Miocene rocks of Gers
(France), Pliocene rocks of Texas (America)
and Miocene rocks of Italy.
• The N. American, Europe, Asia and Africa
Mestodon with long, dense and saggy hairs all
over the body was known as Mammoth.

10. • Deinotherium was a large elephant like
proboscideans that appeared in the
Middle Miocene and survive until the
Early Pleistocene.
• They had a notably flexible necks as well
as the molars were low crowned and had
two crossed ridges. The upper tusks
were absent and the lower tusks were
curved sharply downward and
backwards.
• It was a wide spread genus ranging from
East Africa to the South to Europe and
East to the Indian Subcontinent (Kamlial
Formation of Lower Siwalik of India).

11.  Asiatic elephants include ELEPHAS
genera.
 There are 3 subspecies in Asiatic
elephant :
1. Sri Lankan elephant
2. Indian Elephant
3. Sumatran Elephant
 Elephas is one of the surviving genera in
the family of elephants.
 Asian Elephant have gray skin that is
covered with hair.
 The males are much larger in size with
compare to female.
 Pliocene to recent.

12. • African elephant include
Loxodonta genera.
• There are 2 subspecies in African
Elephant:
1. African Bush Elephant
2. African Forest Elephant
• The African Elephant is typically
larger than the Asian Elephant
and has a concave back.
• African Elephant have larger ears.
• Holocene to Recent.

13.  During the course of evolution of Elephas from Moeritherium , the height
increased from 90cm to 3.5 -5 metres (Elephas Antiquus) &bulk up by 125
times.
 Number of teeth decreases , short crowned teeth with two cross crests
change into large, deep crowned teeth with numerous crosscrests.
 2nd superior incisor pair in moeritherium was large and pointed
downwards to forms the tusk , while inferior tusk were small and
straight.
 Lower jaw became more &more elongated with the increase in the
size of the animal. After Miocene , 2nd shortening took place as
exhibited by elephas.
 The changes in the skull were due to the size and number of teeth,
development of proboscis and tusk. Pillars like short ,strong & stout
limbs with spreading padded toes develop with the increase in size
,neck size also decreases.
 Size decrease during two ancient global warming events ma ago.

14. Fig:- phylogeny
of elephas

15. • Modern day elephants represent only one of many Proboscid families that have
existed throughout history.
• Elephant ancestry spans over 55 ma and includes more than 300 proboscidean
species.
• The two species of elephant today are the Africa and Asian elephants.
• Many complete mastodon skeletons have been discovered from Pleistocene
swamps.
• Most of our early proboscidean knowledge of internal and external anatomy
comes from well preserved nearly complete fossilized mammoth discovered in
soviet union in 1977.
• Fossil records indicate that hunting by man was a factor in eliminating them
,as well as Global warming.

16.  Benton,M.J (4th Edition): Vertebrate Palaeontology.
 Jain,P.C; Anantharaman: Palaeontology (Palaeobiology) Evolution and animal
distribution.
 WEBSITES –
 https://www.google.com/ elephant evolution
 https:// wikipedia.org/ wiki/ elephant evolution
 http://paleosleuths.org/elephants.html

17. THANK YOU