You can google...i tried
Cape Buffalo. On wikipedia it says:
The African buffalo or Cape buffalo...... It is not closely related to the slightly larger wild water buffalo of Asia and its ancestry remains unclearSo you may have to go back to thhe common ancestors of cattle.
The elephant, take a look : http://elephant.elehost.com/About_Elephants/Stories/Evolution/evolution.html . The mammoths are not ancestors, they are more like cousins
Rhino , - they are very ancient species, and the wooly ones were probably just a side-branch.
You can read more HERE, where it among other things say :
Based on some of the fossils that have been located it is believed that the Rhinoceros is closely related to animals such as small horses but that didn’t have any horns. It is possible that the Rhinoceros didn’t have one either but that through the evolution process this developed to help protect them. It is also believed that they used to be much taller and larger than they are today.
Sorry, I don't have more time right now, - try if you can find the others
...I would love to see it
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SUSANNE