Why haven't more larger animals evolved to eat trees?

There were large mammals like mammoths and mastodons during the last ice age, but they became extinct since the end of the last ice age. Today's climate is warmer than the climate during the last ice age, and the African elephant is the largest land mammal. It can peel bark off trees. Anything larger than the African elephant would simply be unable to survive because the climate is too warm. Large animals have proportionally smaller surface to volume ratios. The African elephant partly compensates for this by having large flat ears to increase the amount of body surface. The ears are filled with blood vessels, which allow the hot blood to be cooled by breezes. Think of the elephant's ears as functionally similar to the radiator of an automobile. Animals that are larger would need even larger ears to avoid heat strokes. The warm climate may be why no animals larger than elephants have evolved since the end of the last ice age.

There are some physical limitations to how large a land animal can get before a body can no longer support its weight.

I forget what its called exactly, but basically each extra foot in any direction is an extra cubic foot of stuff.

Thay have as well as many smaller ones too. Have you never been in an area where the trees are managed and the wardens have put fencing around the trees to protect them. Many organisms consume tree bark or damage it getting to organisms, e.g. beetle larvae, under the bark, or to get a sap. The dead, dry bark on older trees tends not to be eaten unless animals are starving, simply because its nutrient content is extremely low.

You serious?

If lots of large animals evolve to eat trees, they eat all the trees, then they all die from lack of food.

The system evolves to balance.

Update.

That stuff is cellulose, which is fcuking hard to digest. The energy required to digest it, and the time taken to digest it, would make the animal lethargic, and easy for predators to catch.

Haven't you seen cows buffalos ziraffe s rihnosaurs elephants?

Oh, they did, but then a great big meteor crashed down and ended that.

Since the end-of-Cretaceous extinction event, we've had ice ages. Ice ages tend to be harsh on big animals.

Because they realized that they weren't getting any muscles from doing so. More muscles=stronger=protect themselves against predators.