Explanation:
members of the same species battle each other to protect their young
Clues such as fossils such as bones, footprints, tar, etc, preserved underground helped inform scientists. You can also count how old a tree is when you cut it open and there are some alive for thousands of years so that is a possible way.
Answer:
In Branchiostoma, it is used mainly for feeding. The pharynx consists of numerous pharyngeal bars, with pharyngeal slits between them. The animal sucks in water through its mouth and forces it out through the pharyngeal slits, capturing small food particles from the water
