In what characteristics did woolly mammoths differ from ordinary elephants?
As the two others pointed out, the first thing that distinguishes mammoths from modern-day elephants is the fur. Sure enough, mammoths had a thicker skin and long, shaggy hair that protected them from the harsh winter conditions.
While elephants live in the tropics of Asia and Africa, and thus have sparse hair on their skins and heads, which help them cool down during the hottest of days.
Mammoths had also fatty humps on their backs, which provided them all the necessary nutrients required to survive in their northerly ranges.
Other physical differences lie in the mammoth’s shorter ears (way shorter than an Asian elephant’s), and longer tusks that could reach up to 4.9 m in length, way longer than an African elephant’s.
Apart from the aforementioned differences, mammoths were not that dissimilar from elephants, for both species are related, belonging to the same order called Proboscidea. Not to mention they share the same size (approximately the same as that of African elephants), the same voluminous head, the same long, flexible trunk, the same number of fingers on each foot, and the same senses of touch and hearing.
In terms of ecology and behavior, mammoths and elephants are highly social animals, and live in large matriarchal herds – meaning the herds that are led by a female –, which they heavily protect against predatory threats.