ISOLATED IDEAS: CRINOID LITERATURE OF THE 16TH CENTURY
Living and fossil crinoids were neither allied nor correctly interpreted. Living comatulid crinoids were considered starfish, and fossil crinoid columnals and pluricolumnals were considered inanimate objects. Different column types were not consistently grouped as similar. Little continuity existed in either understanding or terminology from one author to the next, even early illustrations did not promote terminology stability for crinoids during this time. Although many of these 16th Century natural historians corresponded, most were physically isolated, and their interpretations were greatly isolated.
At the close of the 16th Century, the following were correct or would eventually be adopted: 1, circular and pentalobate columnals and pluricolumnals were related (as crinoids) to one another; 2, the name for pentalobate pluricolumnals continues to be a valid name for the Jurassic crinoid Pentacrinus; and 3, living comatulid crinoids are echinoderms. Given this limited material, key aspects of crinoids that would not be articulated until after the 16th Century were 1, fossil crinoids were the remains of once living organisms; 2, columnals and pluricolumnals of a similar shape were both part of a single larger animal; 3, columnals and pluricolumnals were echinoderms; and 4, columnals, pluricolumnals, and comatulid crinoids together represent a separate class of echinoderms, the Crinoidea. The latter was not recognized until the early part of the 18th Century.