Above: The skeletons of colonial Halysites polyps linked together laterally (that is, side to side), as can be seen in this three-quarter view. In this way, their fossils formed sheet-like folds of mineralized material
Above: The skeletons of colonial Halysites polyps linked together laterally (that is, side to side), as can be seen in this three-quarter view. In this way, their fossils formed sheet-like folds of mineralized material