Jurassic Period, 150 million years B.P. A well-detailed pelagic or free-floating crinoid Sacca pectinate. 210 grams, 10.5 cm (4 1/8 in.). From the Solnhofen Formation, Germany. Private Shropshire, UK collection. While most crinoids attached themselves to the sea floor with a stem and holdfast, crinoids of the orderatulida, also known as feather stars typically do not have stalks. They live on the sea beds and reefs in tropical or temperate waters. [No Reserve]