Which detail in paragraph 2 is interesting, but not needed to find the main idea of that paragraph?

A、Itstailis3inches(7.5cm)long.
B、Scientistsfound40-million-year-oldfossilsofitsancestors.
C、Itweighs0.8ounces(23g).
D、Itsbodyisabout8inches(20cm)long.