Search results
Results from the WOW.Com Content Network
Articulata are a subclass or superorder within the class Crinoidea, including all living crinoid species. They are commonly known as sea lilies (stalked crinoids) or feather stars (unstalked crinoids). The Articulata are differentiated from the extinct subclasses by their lack of an anal plate in the adult stage and the presence of an ...
A stalked crinoid (white) and a comatulid (red) in deep sea, showing the differences between these two sister groups. Most modern crinoids, i.e., the feather stars, are free-moving and lack a stem as adults. Examples of fossil crinoids that have been interpreted as free-swimming include Marsupites, Saccocoma and Uintacrinus. [23]
Pentacrinites is an extinct genus of crinoids that lived from the Hettangian to the Bathonian of Asia, Europe, North America, and New Zealand.Their stems are pentagonal to star-shaped in cross-section and are the most commonly preserved parts. [1]
Antedon bifida is a suspension feeder, catching detritus and plankton with its pinnules as they float past. Larger particles are captured and held by the two larger tube feet of each group of three.
This list of crinoid genera is an attempt to create a comprehensive listing of all genera that have ever been considered to be crinoids, excluding purely vernacular terms.
Sea lilies are crinoids with a calyx and five pairs of feather-like arms standing on a long stalk which is retained throughout the animal's life. This stalk is attached to the substrate by means of an enlarged, terminal disc or alternatively by means of several branching, irregular radicular cirri arising from the lowest part of the stem. [ 3 ]
The beaded crinoid is found in the Caribbean Sea and the Gulf of Mexico. It is found at depths between 15 and 40 metres (49 and 131 ft) and is generally uncommon. These crinoids often live in the same concealed spot for several years and should not be moved by divers as they are very sensitive to changes in water temperature and illumination. [2]
Pentacrinoidea includes most major crinoid groups, such as the living Articulata and extinct Flexibilia (together forming the parvclass Cladida) as well as the extinct Disparida. It is a stem-based taxon , defined as including all crinoids closer to Pentacrinites (a Jurassic articulate) or Apektocrinus (an Early Ordovician cladid ) than to ...