Becuase they were fully aquatic unlike tetrapods today
Answer:
D
Explanation:
Im not exactly for sure on this one, but if i were you, i would choose either A or D . Homeostasis is like the normal for something when they it isnt sick. Its when they are doing good with not really any concerns!
NOUN
the natural coloring matter of animal or plant tissue.
VERB
(pigmented)
color (something) with or as if with pigment.
"pigmented areas such as freckles"
Answer:
to show the function of one organ in the digestive tract in isolation
