The difference in the size of the ears is interesting. Probably a climate adaptation. Although the Indian elephant, not shown, has disproportionately smaller ears than the African elephant which is a larger beast, I would suspect it's not much cooler in India.
Speaking of climate, it is even more interesting to speculate why these beasts disappeared from North America about 11,000 years ago. The Wikipedia article cites the possibility that humans hunted them to extinction but seems to lean toward the view that climate change-global warming 11,000 years ago-led to their extinction.
The Indian elephants are largely found in hillside rainforest fringes, be they along the Himalayan foothills in the north and north-east, or the Western Ghats, in the south.
These places are much cooler than the range that African elephants occupy.
By the way, I had also watched a Nat Geo program where they mentioned the Indian elephant being the closest genetic living relative to the Mammoth.
There's also a theory that a meteor strike caused their extinction. The lack of a crater is attributed to the meteor hitting the ice sheet that covered northern North America at the time.
Leastwise, that's the theory.