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.
Elephants are largest land animals now living. Two genera of the family Elephantidae: Elephasand Loxodonta. Three species of elephants are living today: theAfrican bush elephant, the African forest elephantand the Asian elephant. All other species and genera of Elephantidae areextinct. The Asian and African elephants diverged from acommon ancestor some 7.6 million years ago.
AFRICAN ELEPHANTSingle species with two subspecies. AFRICAN SAVANNA / BUSH ELEPHANT(Loxodontaafricana africana). AFRICAN FOREST ELEPHANT (Loxodonta africanacyclotis).
Four subspecies. Sri Lankan elephant (Elephas maximus maximus),only found on the island of Sri Lanka. Indian elephant (Elephas maximus indicus),foundin India. Sumatran elephant (Elephas maximussumatranus), found only on Sumatra. Borneo pygmy elephant, found only in Borneo.
The African elephant is typically larger than theAsian elephant and has a concave back. African elephants have larger ears. In Asian elephants, only males have tusks, butboth males and females of African elephantshave tusks.
Elephants are now endangered. Today there are about 600,000 Africanelephants and 30,000 wild Asian elephants. There are 170 known fossil elephant speciesthat inhabited the whole Earth, except forAustralia and Antarctica.
The elephants ancestors appeared 50 million years agoin North Africa, were pig sized and resembled a tapir.Elephants living closest relatives are sea cows, likemanatees, dugongs and hyraxes. During the Ice Age there were more 6-7 elephantspecies, including mastodons in North America andmammoths in Eurasia and North America. There are 170 known fossil elephant species thatinhabited the whole Earth, except for Australia andAntarctica.
Parameters Tatrot, Pinjor, and Boulder conglomerate stagesAge 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, inDistrict Chakwal.Principle Exposures Pubbies of Gujrat, Rhotas, Hattar, Kotal Kund, Kala Chitta Range,JARI KAS and Tatrot.Lithology Conglomerates with subordinate interbeds of greenish greySandstone, brown grey Siltstone and great variety of Pebbles. Clay isorange brown in color.
The family Stegodontidae has its origin in theEarly Miocene of Asia and is composed of twogenera, Stegolophodon and Stegodon. The genus Stegodon remained largelyrestricted to Asia, but thrived there throughoutthe Plio-Pleistocene, with a centre of radiationlocated in Southern China (Saegusa, 1996).
In the past, stegodonts were believed to be theancestors of the true elephants andmammoths, but it is currently believed that theyhave no modern descendants. Stegodon is derived from the genusStegolophodon, an extinct genus known fromthe Miocene of Asia. Stegodon is considered to be a sister group ofthe mammoth, as well as the elephants.
Taxon Specimen no. Position Formation/LocalityGPS Co-ordinatesStegodonbombifronsPUPC No.2010/16Skull withpalate andright and leftmolars.Pinjor (JariKas, Mirpur)33° 06 236 N73° 50 012 E
Uptil now fossils of Stegodon have beenrecovered from Indonesia, China, Thailand, Japan Africa and pakistan
Cranium compressed anteroposteriorly with convex skullvertex. Tusks small. Cement gradually increases in the successive teeth. Enamel very thick. Teeth broad and large. Usually a trace of median longitudinal cleft present inanterior ridges. Inner columns of ridge-plates occasionally showaccessory tubercles near the longitudinal cleft. Ridge plate formula:
CementPalateConeletsDentineEnamelRidge plateAneterior sidePosterior side
SPECIES No. of ridgeplatesL (mm) W (mm) W/L indexStegodondhokawanensisspecies new.61/2183 93 51S.pinjorensis (FromOsborn, 1942).141/2-1 360 130 36S.bombifrons(deduced from Falconer,1968, Lydekker,1886 and Osborn,1942.71/2-91/2253-282 93-108 37-38S. insignis (deducedfrom Falconer,1868, Lydekker,1886 and Osborn,1942).81/2-111/2233-287 86-106 37