Choiaとは 意味・読み方・使い方

Choia is a fossil demosponge dating to the Cambrian and Lower Ordovician periods. It was unusual because it was not attached to the sea bed, and radiated spines from the edge of its flattish, conical body, producing an appearance not unlike that of the peak of a big top, with guy lines. Water entered the sponge parallel to the spines, being expelled, presumbaly, from a central opening. It reached 28 mm in diameter. 127 specimens of Choia are known from the Greater Phyllopod bed, where they comprise 0.2% of the community.