3. PHYLUM CHORDATA
SUB PHYLUM VERTEBRATA
CLASS MAMMALIA Linnaeus, 1758
ORDER PROBOSCIDEA Illeger, 1811
SUB-ORDER ELEPHANTIFORMES Tassy, 1988
SUPER FAMILY ELEPHANTOIDEA Osborn, 1921
FAMILY STEGODONTIDAE Osborn, 1918
SUBFAMILY STEGODONTINAE Osborn, 1918
GENUS STEGODON Falconer, 1857.
4. Elephants are largest land animals now living.
Two genera of the family Elephantidae: Elephas
and Loxodonta.
Three species of elephants are living today: the
African bush elephant, the African forest elephant
and the Asian elephant.
All other species and genera of Elephantidae are
extinct.
The Asian and African elephants diverged from a
common ancestor some 7.6 million years ago.
5. AFRICAN ELEPHANT
Single species with two subspecies.
AFRICAN SAVANNA / BUSH ELEPHANT(Loxodonta
africana africana).
AFRICAN FOREST ELEPHANT (Loxodonta africana
cyclotis).
6.
7.
8. Four subspecies.
Sri Lankan elephant (Elephas maximus maximus),
only found on the island of Sri Lanka.
Indian elephant (Elephas maximus indicus),found
in India.
Sumatran elephant (Elephas maximus
sumatranus), found only on Sumatra.
Borneo pygmy elephant, found only in Borneo.
9.
10. The African elephant is typically larger than the
Asian elephant and has a concave back.
African elephants have larger ears.
In Asian elephants, only males have tusks, but
both males and females of African elephants
have tusks.
11. Elephants are now endangered.
Today there are about 600,000 African
elephants and 30,000 wild Asian elephants.
There are 170 known fossil elephant species
that inhabited the whole Earth, except for
Australia and Antarctica.
12. The elephants' ancestors appeared 50 million years ago
in North Africa, were pig sized and resembled a tapir.
Elephants' living closest relatives are sea cows, like
manatees, dugongs and hyraxes.
During the Ice Age there were more 6-7 elephant
species, including mastodons in North America and
mammoths in Eurasia and North America.
There are 170 known fossil elephant species that
inhabited the whole Earth, except for Australia and
Antarctica.
13.
14. Parameters Tatrot, Pinjor, and Boulder conglomerate stages
Age Boulder Conglomerates 0.5-11000,
Pinjor 3.2-0.5Ma.
Tatrot 3.5-3.2Ma.
Thickness 30-500m.
Type Locality Lies along the road Gali Jagir to Sihal, on the north of Soan River, in
District Chakwal.
Principle Exposures Pubbies of Gujrat, Rhotas, Hattar, Kotal Kund, Kala Chitta Range,
JARI KAS and Tatrot.
Lithology Conglomerates with subordinate interbeds of greenish grey
Sandstone, brown grey Siltstone and great variety of Pebbles. Clay is
orange brown in color.
15. The family Stegodontidae has its origin in the
Early Miocene of Asia and is composed of two
genera, Stegolophodon and Stegodon.
The genus Stegodon remained largely
restricted to Asia, but thrived there throughout
the Plio-Pleistocene, with a centre of radiation
located in Southern China (Saegusa, 1996).
16.
17. In the past, stegodonts were believed to be the
ancestors of the true elephants and
mammoths, but it is currently believed that they
have no modern descendants.
Stegodon is derived from the genus
Stegolophodon, an extinct genus known from
the Miocene of Asia.
Stegodon is considered to be a sister group of
the mammoth, as well as the elephants.
18. Taxon Specimen no. Position Formation/
Locality
GPS Co-
ordinates
Stegodon
bombifrons
PUPC No.
2010/16
Skull with
palate and
right and left
molars.
Pinjor (Jari
Kas, Mirpur)
33° 06 236 N
73° 50 012 E
20. Uptil now fossils of Stegodon have been
recovered from
Indonesia,
China,
Thailand,
Japan
Africa
and pakistan
21. Cranium compressed anteroposteriorly with convex skull
vertex.
Tusks small.
Cement gradually increases in the successive teeth.
Enamel very thick.
Teeth broad and large.
Usually a trace of median longitudinal cleft present in
anterior ridges.
Inner columns of ridge-plates occasionally show
accessory tubercles near the longitudinal cleft.
Ridge plate formula:
23. SPECIES No. of ridge
plates
L (mm) W (mm) W/L index
Stegodon
dhokawanensis
species new.
61/2
183 93 51
S.pinjorensis (From
Osborn, 1942).
141/2
-1 360 130 36
S.
bombifrons(deduce
d from Falconer,
1968, Lydekker,
1886 and Osborn,
1942.
71/2
-91/2
253-282 93-108 37-38
S. insignis (deduced
from Falconer,
1868, Lydekker,
1886 and Osborn,
1942).
81/2
-111/2
233-287 86-106 37
24. SPECIES dP2 dP3 dP4 M1 M2 M3
S. insignis 2 5–6 7 7–8 7–8 10–11
S.
orientalis
3 5–6 6–7 6–7 6–8 11–12
