Which of the following vertebrates are ectothermic?

hummingbirds

newts

kangaroos

horses

The correct answer for the question that is being presented above is this one: "newts." The vertebrate that is ectothermic is a newt. A newt is a semiaquatic amphibian of the family Salamandridae, although not all aquatic salamanders are considered newts. Ectothermic is an animal that is dependent on external sources of body heat.