Embrithopods Proboscidea Arsinoitherium early Oligocene 50 MYA Rhino size Paired horns Fed on coarse leafed swamp plants Large grazers and browsers Huge cheek teeth for grinding plants Dispersal worldwide except Australia and Antarctica Earliest well known one Pig sized trunkless African Moeritherium 35 MYA Long columnar limbs Large fatty pads on feet Mastodonts Mammut Mammut nipple tooth Different teeth from living Elephantidae 3 premolars and 3 molars Progression in jaw back to front Tusks in both sexes Lower jaw tusks in many Browser open spruce forest 4 tusked mastodonts Ampelodon Platybelodon Short tusks and broad lower incisors Used shovel to scrape up aquatic plants Family Elephantidae 3 lineages from a rapid radiation out of Africa Elephas most diversity two lines Europe Africa and Asia Mammuthus widest geographic distribution Loxodonta Palaeoloxodon smallest and largest big elephants Large columnar legs elongated flexible trunks tusks Sister taxa forest elephants giant Palaeoloxodon Sister taxa asian elephants mammoths Elephantidae molariform teeth Occlusal surface vertical plates alternating enamel with dentine Serial replacement to compensate for wear conveyor belt Worn down as elephant ages Many transverse ridges loxodont Molars erupt pushed as conveyor belt from back to front Palm of hand manus and arch of foot pes supported by an elastic ball Elephantidae Feet Digits radiate out Digitigrade Graviportal Elephantidae Skull High for muscles ligaments Leverage for tusks Pneumatic sinuses Brain cavity Nasal passage Starting on Slide 24 Asian Elephant whats being passed on is very small and diminutive tusks Loxodonta Africa vs Elephas Asia Ear size Number of nails on foot Height at shoulder and hip Convex or concave foreheard Ribs 21 pairs in Af 20 in As Number of caudal tail vertebrae Number of finger like structures on end of trunk Loxodonta africana Largest land mammal 5 10 tons Feeds on coarse vegetation in open savanna and marshes Low nutrient content food Intake large Hindgut fermenter Feeds 70 of active time Difficult to tame never for work Why Plays into the strong connection of the Asian elephants and humans they have basically been domesticated African Elephants have never been domesticated Mostly located in sub Saharan Africa Roman times north to the Mediterranean and Syria How Hannibal used war elephants Loxodonta cyclotis Smaller African forest elephant Straight tusks rounder ears DNA L cyclotis and africana genetically different as lions and tigers as great as between L africana and E maximus Closely related to giant extinct Paleoloxodon India and Southeast Asia including Sumatra Borneo Sri Lanka Formerly in china to north to Yangtze river They prefer grasses different from african elephant but they also consume bark roots leaves and stems of trees vines and shrubs Elephas maximus Jungle to grassy plain Gregarious Captured and trained for work African Elephant Ecology Almost exclusively browsers hindgut fermenters like horses and rabbits Over 12 hours one animal fed on 64 species of plants of 28 species Grass is used only after suitable browse is gone Devastation resulting from feeding downed trees uprooted stripped bark Role of migration local devastation and regeneration Farm saplings fertilize soil move on Stands recover elephants return Ecology and Society Elephants have advanced social organisms Society based on Closeness and intimacy among females Power of the matriarch Length of time associations endure Elephant population structure 2 3 tiered hierarchy of sociality Family unit 10 20 females and young Matriarch largest oldest strongest Rallies others and leads Gradually replaced as she ages sudden loss causes instability Takes lead when confronting danger Takes the rear position in retreat Home range 14 52 Km 2 Adolescent bulls play fight At 13 form bachelor herds Size determines dominance Small bulls may form coalitions to dominate a mid sized bull Large adult bulls are solitary maintain small home range along paths to water holes Kinship group ensemble of family groups that remain nearby show personal familiarity probably arise from splitting family groups Clan 100 250 individuals that aggregate together during mass migration Cooperation and altruism Calves of both sexes are treated equally Nurse any lactating female Adolescent cows aunts Family members assist defend one another African elephant communication Visual signals vocalizations and scent Hostility shown by series of postures and sounds Middle move toward enemy crack of ears extend trunk forward trunk swish and Lowest standing tall head lifted peer over tusks ears cocked forward trumpet Highest full charge ears flapping trunk held high trumpet loudly Hearing and vocalizations Hearing as acute as humans Trained Asian elephants recognize up to 24 verbal commands Vocalizations include growls trumpets squeals shrieks Infrasound 14 24 Hz not audible to humans but can be sensed as air pressure vibrations Probably picked up by the elephant skeleton foot pads Chemical Communication Very keen sense of smell Sense danger man lion etc Bulls check sexual condition of cows Family group members track one another Temporal gland Produces a strong smelling secretion Begins at 12 15 years sexual maturity Maximum release when excited or under stress African both sexes rub secretion on trees Asian only males produce secretions Musth Courtship and Mating Male society regulated by smell Socially immature males release honey like odors to avoid conflict with adult males Older musth males malodorous combinations deter young males Females advertise estrus by odor a mature bull in a cow herd indicates a cow is in estrus Adult male and estrus female form a consort Courtship includes touching with trunks During mounting cows and juveniles circle couple Gestation 22 months nursed for 6 months calf is weaned at 12 months Testes are in the same position as ovaries Consistency of temp in body could be beneficial Protection