Dolphins have a four-chambered heart.
4
Two
four chambers
A fish's heart have Two chambers .
The fox has a 4 chambered heart.
4 chambers as they are mammals.
The dolphin's heart has four chambers. This characteristic shows that the dolphin evolved from land based mammals, rather than from amphibians, which only have three chambered hearts.
There is no such thing as a fiber chamber of the heart.
The function of the dolphin heart is to move blood and oxygen through the tissues and organs of the animal. Without a heart, the dolphin would be unable to survive.
1
bird:3 human:4
A spider monkey has four chamber like the human heart