My seminar At Periyar University Salem I'm Thomas chinnappan Keeranur Pudukkottai tamilnadu India @tcoftheworld @tcorganization

1. Palaeontology
BY:
THOMAS CHINNAPPAN .A ,
M.SC.APPLIED GEOLOGY,
PERIYAR UNIVERSITY,
SALEM.

2. Evolution of
Elephas
(Elephant)

3. Introduction :
• Elephants are giant terrestrial mammals.
• Elephants distantly present communicate via
infrasound.
• Elephants are commonly found in Africa and Asia.
• Male elephants are generally taller than females.
• Elephants have plantigrade posture.

4. • In 20 mya , travels africa & Europe & asia
• 16 mya north america & 3mya South America
• Found oldest elephant fossils
• Eritheriyum azzouzorum
• 60 mya & not look like elephant

5. • KINGDOM : Animalia
• PHYLUM : Chordata
• CLASS : Mammalia
• ORDER : proboscidea
Taxonomy :

6. • Multicellular eukaryotic organisms (metazoa)
• Broad range of animal species
• Animal obtain nutrition
• 565 & 525 mya
• Evolved during cambrian
Kingdom : animalia
Phylum : chordata
• Belongs to vertibrate animals
• Spinal cord
• Four anotomical features

7. Class : mammalia
• Belongs to mammalia
• Because it gives birth & feed milk to there babies
• 300 mya
Order : propocidea
• Trunks by probocidea
• 352 species of probocidea
• Adaptive abilities
• Elongated of mouse

8. Evaluationary Trends :
• Increase in size and weight( elongation of limb
bones and enlarged skull).
• Development and elongation of proboscis.
• Modification of second pair of incisors into tusks.
• Modification of dentition from bunodont (molar
• teeth with rounded cusps) to lophodont (grinding
• surface of molar teeth with transverse sutures).

11. Rate of Evolution :
• The evolution of Africa elephants can be
described as punctuated equilibrium because
new species changed most at the time they
branched from the parent species.
• The organisms changed little as time went on
but some speciees became extinct, and some
new species also developed.

12. Progeny lines with time :
EOCENE Moeritherium
OLIGOCENE Palaeomastodon Phiomia
True Mastodon
MIOCENE Bunomastodon Miomastodon
Deinotherium
PLIOCENE Tetralophodon
Steglophodon
Stegodon
Trilophodon
Phiomastodon
PLEISTOCENE Mastodon
Stegomastodon
RECENT Mammoth
Loxodonta
Elephas
Time period Main lines Side lines

14. • Swamp dweller.
• About size of pig.
• Bunodont dentition
• No proboscis.
• Snot elongated.
• Elongated body.
• Short legs.
• First lower incisor small whereas second lower incisor
large suggesting development of tusks in later stages from
it.
Main lines in Evolution :
1) Moeritherium

16. 2) PALAEOMASTODON :
• Arose from moeritherium
• During oligocene.
• Proboscis short.
• Upper tusks more elong
• Lower tusks are short.
• Gave rise to two lines Bunomastodon

18. •Arose from Palaeomastodon.
•Tusks on both jaws.
•Proboscis long.
•Gave rise to several lines.
3) BUNOMASTODONN :

20. 4) TETRALOPHODON :
• Lived during pliocene.
• Four cusps in four milk teeth and in first and
second molar teeth.
• Proboscis similar to modern elephants.
• Four tusks present.
• Molar high crowned.
• Each molar with four crossing cusps.
• Gave rise to two lines : Stegomastodon
(sideline) and Steglophodon (main line).

22. 5) STEGLOPHODON :
• Lived in pliocene.
• Early records seen in Japan.
• Early specimen showing bunodont indicating its
origin from bunodont ancestors.
• Only upper tusks present.
• Lower tusks absent.

24. 6) STEGODON :
• Widely believed to be originated from steglophodon.
Some believe this occurred in Afica and others believeit
to have occurred in Asia.
• Lived upto pleistocene.
• Skull shortened.
• Anterior part of mandible shorter
• Long proboscis.
• Tusks are huge and generally tusks absent.
• Teeth were high crowned.
• Traditionally believed of Loxodonta, Elephas and
Mammoths.

26. 7. MAMMOTH :
• Like modern elephants but ext
• Lived during pleistocene.
• Strongly curved and twisted tusks.
• Plate number and lamellar frequency in teeth
increased with time.
• Mammoth were generally adapted to cold
environment.

28. 8. MODERN ELEPHANT :
• Represented by two genera, African elephant
Loxodonta and Asian elephant Elephas.
• Loxodonta have cheek teeth with high crowns.
• Loxodonta is only taxa with thick rhomb shaped
lophs.
• Feeding pattern is browsing and grazing.
• Early species of Elephas have low crown, low lamellar
frequency and low enamel.
• African elephants are characterized by great
palmleaf-like ears, while Asian elephants ears are
smaller.

30. SIDE LINES IN EVOLUTION OF
ELEPHANT :
• Oligocene period.
• Size double of Moeritherium
• Tusk present in both jaws.
• Skull large with air cells.
• Some evolutionists believe it to be in main line
of evo while others considered it in side line
evolution.
1.PHIOMIA :

31. 2. DEINOTHERIUM :
• Side line evolution.
• Miocene period.
• Lived in swamps.
• Proboscis present
• Dentition lophodont present as an adaptation to leaf eating.
• First two premolars absent.
• Since only two lobes present in second molar teeth whereas three lobes in
second molar of palaeomastodon, its believed to have more primitive
ancestor.
• Only proboscidean in which upper pair of tusks absent.
• Tusks curved downward and backward.
• Size of deinotherians increased with time. Cause of extinction is that they
couldn't change their eating habits with changing environment espedially
during winter season.

33. 3. MASTODON :
• Size of elephants.
• * Lived from upper oligocene to pleistocene.
• Molar bilophodont.
• Lower tusks absent.
• Upper tusks curved as modern elephants.
• Air spaces in skull.

34. 4. TRILOPHODONT :
• Present during pliocene
• Size of modern elepha
• Four tusks present.
• Upper tusks elongated lower tusks short.
• First two molars have three pairs of transversely
aranged
• Molars low crowned cusps.

35. Evidence of Evolution
*Modern day elephants represent only one of many
Proboscid families that have existed throughout history.
*Elephant ancestry spans over 55 million years and includes
more than 300 Proboscidean species.
*The earliest member of the Order Proboscidea was
Moeritherium. Moeritheriums lived during the Eocene
epoch about 50 to 55 million years ago. Although the
animals did not possess trunks, the structure of the skull
indicates they had an elongated snout.
*Analysis of skull anatomy reveals all members of the
Elephantidae family had well-developed trunks based on
the elevated position of the nostrils.

39. Thankyou