I have Four Corners

I am a sweet fruit. I am not big.

I wear a beautiful red dress. There is a small green hat on my head.

My body has a shape of a heart.

Who I am?

If 

111 = 13

112 = 24

113 = 35

114 = 46

115 = 57

Then

116 = .....???

I live in Africa. I am Yellow and Brown.

I eat leaves. I have a long neck.

Who I am?

I am the eighth planet from the Sun. My twin brother is Uranus.

I am the farthest planet from the Sun.

I am a desert animal. I am tall.

People like to ride on me. 

Who I am?