海绵硬蛋白
hǎi mián yìnɡ dàn bái
- 名spongin
海绵硬蛋白-
虽然现在所发现的海绵中约有90%都属于寻常海绵纲，但此类海绵化石比其他类型的更加罕见，因为它们的骨骼由相对柔软的海绵硬蛋白组成，不易形成化石。3.水母
Although about 90 % of modern sponges are demosponges , fossilized remains of this type are less common than other types because their skeletons are composed of relatively soft spongin that does not fossilize well . 3.Jellyfish