Fossil Crinoids Gallery

A virtual museum of crinoids from all over the world

Classic Crinoid Sites

Selection of fine specimens

























Click on any Period to enter the Gallery

Fossil Crinoids in Geologic Record

Fossil Crinoids have graced the oceans for more than 500 million years. Among the most attractive fossils, crinoids had a key role in the ecology of marine communities through much of the fossil record, and their remains are prominent rock forming constituents of many limestones.

Crinoids in Cenozoic Era

The Cenozoic Era (66 million years ago through today) is the "Age of Mammals." Birds and mammals rose in prominence after the extinction of giant reptiles. 

As a result of the distribution of sea and land during the Tertiary, which was similar to that of today, most marine sediments were deposited in shallow water close to present coastlines. Therefore, there are only a few chances to collect from deposits in which crinoids might be well preserved. It must be assumed that, starting from a low at the Cretaceous–Tertiary boundary, the number of crinoid species has steadily increased during the Tertiary to arrive at the present diversity. The poor fossil record of Tertiary crinoids is, therefore, most probably due to non-preservation rather than to a lack of species.

Crinoids in Mesozoic Era

The Mesozoic Era (252 to 66 million years ago) was the "Age of Reptiles." As climate changed, sea levels rose world-wide and seas expanded across the center of North America. Large marine reptiles flourished in these seas. 

Following their near-demise during the end-Permian extinction, crinoids underwent a major evolutionary radiation during the Middle–Late Triassic that produced distinct morphological and behavioral novelties, particularly motile taxa that contrasted strongly with the predominantly sessile Paleozoic crinoid faunas. Crinoids recovered during the Triassic and re-occupied almost all ecological niches they had held in Palaeozoic times. The Late Triassic extinction event was the last major perturbation in crinoid history. Although many taxa have come and gone since then, the overall changes between the Late Triassic and the present day have been comparatively gradual. The occurrence of the pseudoplanktonic crinoids is an enigma of the Jurassic.  Even at the end of the Cretaceous, when so many other elements of the fauna experienced profound changes, crinoids appear to have suffered no great change in diversity, although it is perhaps significant that no pelagic microcrinoids survived the end-Cretaceous event.

Crinoids in Paleozoic Era

During the Paleozoic Era (541 to 252 million years ago) fish diversified, fossils include trilobites and cephalopods such as crinoids, as well as insects and ferns. The greatest mass extinction in Earth's history ended this era.

Crinoids reached their highest generic richness and overall abundance during the Mississippian, which thus has been dubbed the Age of Crinoids. The causes are hypothesized to be from the coincidence of two factors. First, in the wake of the Late Devonian mass-extinction event, the five major crinoid groups recovered and radiated in the Early Mississippian. The advanced cladids continued to radiate from their origin in the Early Devonian and reached a peak in the Middle Mississippian (Visean) that was not exceeded again until the Middle Pennsylvanian (Moscovian). Second, the Late Devonian mass-extinction event destroyed the extensive coral-stromatoporoid platform-edge reefs that had restricted circulation on carbonate platforms and limited the abundance of crinoids, which are stenohaline. The resulting carbonate ramps during the Mississippian had improved circulation, producing stenohaline conditions that resulted in an abundance peak for crinoids, recorded by widespread regional encrinites on multiple continents. This increased habitat space was ideal for camerate crinoids and resulted in a new radiation of camerate crinoids. The simultaneous radiation of pinnulate cladids and the short resurgence of camerates were responsible for the biodiversity spike in the Mississippian. The Age of Crinoids ended with a major drop in sea level at the end of the Mississippian as massive glaciers formed on Gondwana and epicontinental seas were drained.