Crinoid Species Research Articles

A new species of comatulid crinoid from the Duck Creek Formation of the Washita Group (Lower Cretaceous) north-central Texas

A new species of comatulid crinoid from the Duck Creek Formation of the Washita Group (Lower Cretaceous) north-central Texas

Reproduction in five species of crinoids at Lizard Island, Great Barrier Reef

Reproduction in five species of crinoids [Himerometra bartschi (A. H. Clark), H. robustipinna (P. H. Carpenter), Cenometra bella (Hartlaub), Colobometra perspinosa (P. H. Carpenter), and Oligometra serripinna (P. H. Carpenter)] was studied at Lizard Island, Queensland, over 24 mo, from April 1981 to March 1983 (except for O. serripinna —June 1981 to March 1983). All five species of crinoids were dioecious, although a few instances of synchronous hermaphroditism were noted in H. bartschi, C. perspinosa, and O. serripinna. Gonad morphology and the sequence of developmental stages were similar in each species. Within individuals, gametogenesis was synchronous in gonads both along and between arms, except in some proximal and distal genital pinnules in which gonads never matured. Within a species, there was a degree of synchrony of gametogenesis in a sample, but the level of gametogenic activity varied considerably between years. A high level of continuous reproductive activity was observed in H. bartschi, H. robustipinna, Cenometra bella, and Colobometra perspinosa from about mid-summer to early/mid-winter, while O. serripinna probably had a bimodal reproductive cycle with peaks around February and June. There was a significant 1:1 male:female sex ratio in the populations sampled, and unsexable individuals were significantly smaller (as determined by maximum arm length) than either sexable males or females.

Biochemical composition of antarctic echinoderms

1. 1. The biochemical composition of the body components of 24 species of echinoderms from McMurdo Sound, Antarctica were ascertained. These included 14 species of asteroids, three species of ophiuroids, three species of echinoids, three species of holothuroids, and one species of crinoid. 2. 2. Levels of ash (% dry wt) were high, reflecting large amounts of skeletal material in the asteroid body wall (31.3–80.3%), the ophiuroid disc (48.7–71.7%) and arms (56.8–72.7%), the echinoid test (79.5–80.5%), spines (88.6%) and lantern (79.3%), the holothuroid body wall (31.5–36.2%) and the crinoid cirri (83%), calyx (79%) and arms (63.5%). 3. 3. Levels of insoluble and soluble protein and lipid were high in the nutrient storage organ (pyloric cecum) of the asteroids and the gut of the ophiuroids. 4. 4. Analyses of the biochemical composition of the gonads of 16 echinoderm species reveal high levels of lipid and soluble and insoluble protein. In 88% of the species levels of lipid were higher in ovaries when compared to testes. 5. 5. Levels of carbohydrate were low in all body components. 6. 6. The biochemical composition of antarctic echinoderms is similar to species from other latitudes. High levels of lipid in ovaries of most antarctic echinoderms appear to be related to the preponderance of lecithotrophy at high latitudes.

Diel patterns of emergence of crinoids (Echinodermata) from within a reef at Lizard Island, Great Barrier Reef, Australia

Periods of emergence of nine species (88 individuals) of crinoids (Comanthus parvicirrus, Clarkcomanthus albinotus, Comaster multifidus, Oxycomanthus comanthipinna, Oligometra serripinna, Comanthus gisleni, Comanthus wahlbergi, Comatula purpurea, and Oxycomanthus exilis) were monitored at Lizard Island, Queensland, over seven days in March 1983. One species (O. serripinna) was fully exposed and the others partially exposed. Two patterns of emergence were species-specific: emergent both day and night, and emergent only at night. Intraspecific exposure patterns were generally synchronous in six species and asynchronous in three species. The number of species visible was relatively constant during all dives, while at least twice as many individuals were visible at night compared to day. Degree of emergence was determined as the number and length of arms extended into the water column. Except for species fully exposed, degree of crinoid emergence was generally minimal at midday and maximal at twilight and night. Increases in both number of crinoids visible, and the amount of an individual's emergence, corresponded to decreasing light intensities, even during daytime. It is suggested that the patterns of exposure are a response to increased prey abundance at twilight and night, and also a means of avoiding diurnal predators. Gonads on the longest arms of some partially exposed crinoids were not extended into the water, thus protecting the gonads from predators.

Aerosol suspension feeding and current velocities: distributional controls for late Osagean crinoids

Distributional patterns of late Osagean (Mississippian) crinoids from the east-central United States are examined using multivariate analysis of crinoid species diversity and species abundance data. We confirm previous hypotheses that three well-defined crinoid associations existed during the late Osagean. These associations were dominated, respectively, by 1) monobathrid camerates preserved in carbonate packstones; 2) poteriocrine inadunates in higher-energy siltstones and sandstones; and 3) disparid inadunates, cyathocrine inadunates, and flexibles in mudstones where neither monobathrids nor poteriocrines dominated. In conjunction with petrologic data on the enclosing sediments, the analyses suggest that these associations occurred along a spectrum of increasing current velocity at the seafloor. Camerates, poteriocrine inadunates, and flexibles are interpreted to display preferences for specific environmental conditions, whereas disparid and cyathocrine inadunates are inferred to be environmental generalists.The different environmental distributions of the major crinoid groups are interpreted to be a function of the mode or modes of aerosol filtration feeding used by each group. This inference is possible through functional morphologic and morphometric studies of crinoid arms, because the skeletal elements of the arms, which are commonly preserved, are directly involved in feeding.

Unusual crinoids from the Ramp Creek Formation (Mississippian), Indian Creek, Montgomery County, Indiana

Three new species of inadunate crinoids of Early Mississippian age from the Ramp Creek Formation along Indiana Creek, southern Montgomery County, Indiana, are described. Poteriocrinites amplus n. sp. is the first correctly identified record from North America of this long-ranging Old World genus. Poteriocrinites macropleurus and P. doris from the Burlington Limestone are here reassigned to Springericrinus. Interchange of Mississippian crinoid genera between Europe and North America is rare, many genera being endemic. Springericrinus sacculus n. sp. is the youngest reported species of this North American counterpart of Poteriocrinites. This new species exhibits two advanced features: presence of only one, rather than three, anal plate, and presence of 3 or 4, rather than 1 or 2, primibrachial plates per ray. The third species, Decadocrinus stellatus n. sp., presents an interesting blend of characters usually used as generic discriminators between Decadocrinus and Histocrinus. The specimen could possibly be considered to be an intermediate between these two genera that are currently placed, incorrectly we believe, in two separate superfamilies.

A new Devonian species of flexible crinoid from the Lost River Range, east-central Idaho

The new flexible crinoid Para clidochirus n. gen. is described, with P. keyserensis (Springer, 1920) as the type species. A new species, P. schultzi, is described from the Late Devonian of Idaho.

The ordovician crinoid genus Caleidocrinus Waagen and Jahn, 1899

AbstractConfusion concerning the precise nature of the crinoid species Caleidocrinus multiramus is due to an erroneous description by Springer which was based on two specimens which were not types. The genus Caleidocrinus is unusual amongst inadunates in having interbrachial plates. The two recognized species are assigned to separate subgenera. C. multiramus, the type species, is assigned to Caleidocrinus s. s. subgen. nov, and has tall, shield‐like radials, concealed basals, and brachials with unsculptured latera. C. turgidulus has broad radial plates supported by triangular basals and brachials with lateral depressions adjacent to plate sutures. It is assigned to Hwcleyocrinus subgen. nov. C. barrandei is a synonym of C. multiramus. Ristnacrinus is probably closely related to this genus.

Pigments of Marine Animals. XV. Bianthrones and Related Polyketides from Lamprometra palmata gyges and Other Species of Crinoids

The range of presumably polyketidal constituents in comatulid crinoids has been extended by examination of Lamprometra palmata gyges Bell to include three 10,10′-bianthrones derivable from the known crinoid constituents, 1,3,8-trihydroxy-6-propyl-9,10-anthraquinone and the corresponding 6-(1′-hydroxypropyl) quinone . From other species, a 1,1′- bianthraquinone, a phenanthroperylene-7,14-quinone and probably 8- acetyl-1,2,4,5,7-pentahydroxy-9,10-anthraquinone have been identified in addition to other pigments previously known from crinoids. The polyketides present in particular comatulid crinoids may be determined by natural selection from a wide range available to crinoids generally, rather than by chemotaxonomic considerations.

New host and locality records of the commensal adyte crinoid/cola (Polychaeta:Polynoidae)

Adyte crinoidicola (Potts, 1910) is recorded from Australian waters for the first time. An amended description is provided. The number of known host crinoid species is increased from 3 to 17.

Modern Deep-Water Coral Mounds North of Little Bahama Bank: Criteria for Recognition of Deep-Water Coral Bioherms in the Rock Record

ABSTRACT Deep-water, ahermatypic coral mounds are present at water depths of 1,000-1,300 m on the lower slope north of Little Bahama Bank. The mounds are patchily distributed over a minimum area of 2,500 km2 and typically display 5-40 m of relief above the surrounding sea bottom. A diverse benthic community exists on these apparently unlithified mounds, including l 1 genera and 16 species of ahermatypic coral (Bathypsammia, Caryophyllia, Deltocyathus, Desmophyllum, Enallopsammia, Javania, Madrepora, Polymyces, Solenosmilia, Stephanocyathus, and a previously undescribed genus), alcyonaceans, gorgonians, antipatharians, hydroids, ophiuroids, crinoids, barnacles, galatheid crabs, polychaetes, gastropods, bivalves, and sponges. Conspicuously absent from the coral fauna are Lop elia and Dendrophyllia, common deep-water corals in other parts of the Atlantic. Radiocarbon dates on fresh coral and gorgonian fragments of 940 ± 40 and 860 ± 50 years indicate the mounds are at least in part Recent and are probably actively forming today. Bored and stained corals date at around 22 10314C years B. P., which establishes a minimum age for these mounds. We speculate that the mounds develop on sea-floor perturbations in areas where strong bottom currents provide needed oxygen and nutrients to the fauna. The mounds may have undergone multi-stage evolution from colony to thicket to coppice to bank. This evolution may be accomplished through the in situ contribution of skeletal material along with the baffling and trapping of fine-grained carbonate sediment winnowed from adjacent areas by bottom currents. If found in the rock record, the coral mounds north of Little Bahama Bank would probably be considered bioherms. Geologists should thus be aware that scleractinian bioherms are not uniquely shallow-water in origin. The distinction between ancient deep- and shallow-water coral buildups involves using multiple recognition criteria, including: 1) presence or absence of algae; 2) diversity of corals; 3) coral morphology and microstructure; 4) abundance of planktonic/benthonic components; 5) microborings; 6) surrounding litho- and biofacies; 7) stable isotopes of carbon and oxygen; and 8) trace element geochemistry, particularly Sr and U concentrations. The distinction between deep- and shallow-water bioherms is crucial to regional paleoenvironmental and stratigraphic interpretations.

Two new camerate crinoid species from the Permian of eastern Australia

Two new camerate crinoids, Dichocrinus? australis sp. nov. and Dichocrinus? darlingtonensis sp. nov., are described from the Early Permian of eastern Australia. Both are tentatively assigned generically because the precise morphology of their respective tegmens is not known. The species bear a close resemblance to Early Carboniferous North American representatives of the genus. They are interpreted as end members of a conservative and cosmopolitan crinoid lineage that experienced little change in the Palaeozoic. D? darlingtonensis is thought to be ancestral to D? australis.

Lost & Found: 54. Murchison, Roderick Impey (1792-1871)

Dr. James C. BROWER of the Department of Geology, Syracuse University, Syracuse, New York 13210 USA is working on Silurian crinoids and seeks the holotypes of two of John Phillips species of Silurian crinoids described in Murchison's Silurian System 1839 page 674 and plate 17 figs. 4 and 5 as Dimerocrinites decadactylus Phillips sp. nov. fig. 4 and Dimerocrinites icosidactylus Phillips sp. nov. fig. 5 Murchison gave the crinoids to Phillips for description and often did not note from whose collection particular specimens came and to which many presumably then returned. Murchison did record that the first of these specimens (pi. 17 fig. 4) came from a Mrs. Downing -...

Host‐specific pit‐forming epizoans on Silurian crinoids

Brett, Carlton E. 197807 15: Host-specific pit-forming epizoans on Silurian crinoids. Lethaia, Vol. 11. pp. 217–232. Oslo. ISSN 0024–1164. Circular-parabolic pits occur commonly on the endoskeletal remains of certain Paleozoic crinoids. Detailed study of several hundred specimens, representing about 30 pelmatozoan species from the Upper Silurian Rochester Shale of New York and Ontario, reveals that such pits occur exclusively in seven species of crinoids. Furthermore, there are consistent differences in the morphology and orientation of holes occurring on the different crinoid species. This suggests that distinct epizoan species settled selectively on given hosts. The relationship between the hole-producing epizoans and crinoid hosts is inferred to have been a form of dependent commensalism. Preliminary surveys of other Paleozoic crinoid assemblages reveal similar host-selectivity by pit-producing epizoans. Crinoidepizoan pairs apparently co-evolved through considerable spans of geologic time as related genera and species of different ages, from Silurian to Pennsylvanian, exhibit similar pits.

The Swain Reefs Expedition: Crinoidea

Eighteen species of crinoids collected at the Swain Reefs, 21°43′S 152°25′E; N.E. of the Capricorn Channel, are discussed, one of these, the unusual five-armed Eudiocrinus serripinna A. H. Clark, representing a genus new to the Australian fauna. The range of two other species, Oligometra serripinna (P. H. Carpenter) and Ptilometra australis (Witton), are extended into Queensland waters by the expedition's work.

Ecology of the northern Red Sea crinoids and their Epi- and Endozoic fauna

Fourteen crinoid species are found along the coral reefs of the northern Red Sea that form aggregations of different species at various depths. The shallowest aggregation consists partly of Lamprometra klunzingeri and Capillaster multiradiatus, occurring subtidal to a depth of 2 to 5 m. Of this group, Heterometra savignii inhabits depths down to 12–15 m. Further down, another group of 10-armed crinoids occurs, dominated by Decametra chadwicki and Oligometra serripinna. The deepest aggregation of crinoids occurs at 45 m; its most common members are Colobometra arabica and Comaster distinctus. Feeding on micro- and nanoplankton, shallow-water crinoids show a circadian activity rhythm; in deeper aggregations (10 to 12 m), this behaviour changes with decreasing illumination, to a diurnal activity rhythm. The symbiotic animals living on crinoids comprise 27 taxons, among them Copepoda (6 species), Mollusca (2 species), Polychaeta (11 species, especially Myzostomida); Ophiurida (1 species), Crustacea, Decapoda (6 species); and the clingfish Lepadichthys lineatus. These symbiotic animals form food webs at various depths, according to the distribution of their crinoid host. The occurrence of Indo-West Pacific and Mediterranean commensals on the same crinoid in the Gulf of Aqaba is of special interest.

Feeding behavior and ecology of shallow-water unstalked crinoids (echinodermata) in the Caribbean Sea

The feeding behavior, living position, and skeletal morphology of 8 species of reef-dwelling Caribbean comatulid crinoids are intimately related to the regime of water movement prevailing in the microhabitat. These adaptations are related to the dependence of the crinoid suspension-feeding mechanism on externally produced water movements for a continuous food supply. Greater numbers of co-occurring comatulid species (6 to 7) and larger populations have been found off Colombia and Panama than off Curacao and Jamaica (4 species). It is suggested that these differences may be related to increased or diversified primary productivity close to the larger land masses. Overal food availability as determined by primary productivity may, thus, be an important factor controlling the regional diversity and abundance of these species.

Five new genera and two new species of unstalked crinoids

Five new genera and two new species of unstalked crinoids

New Crinoids from Coplow Knoll, Clitheroe, with Lists of Carboniferous Limestone Crinoid Species

One purpose of this paper is to place on record a new crinoid genus from Coplow Knoll, Clitheroe. The name Edapocrinus is proposed for its reception. Another is to note the discovery of two nearly complete crinoids at the same locality. This type of preservation is very rare at Coplow since the great majority of specimens found there consist of calices only and, except Actinocrinus and allied genera which have the lower brachials incorporated in the cup, it is only on a rare occasion that one finds a cup with any portion of the arms in position. In a paper to this Magazine, (1928, p. 246), I noted the discovery of the rare Flexible species, Euryocrinus rofei Bather and Gregory, which had part of the arms preserved, and remarked then on the scarcity of complete specimens of any species. Besides Coplow, this seems to apply to all the knolls in the Clitheroe region. Phillips, in his Geology of Yorkshire (1836), describes a considerable number of species from “Bolland”, most of which appear to have been collected by Gilbertson of Preston, and possibly some of the specimens were found at Coplow. All are cups only, with the exception of Poteriocrinus, now Taxocrinus nobilis, which is a complete crown. On different occasions during the last eight years, when I have made an annual visit to Coplow, I have found odd portions of arms, greatly displaced and not attached to any cup, usually in such a jumbled state that they were indeterminable.

XIX. On Carboniferous Crinoids from Fyfe, with notes on some localities and provisional lists of species

Introduction. Viewing a section of one of the Lower Carboniferous Limestones, and noting the prodigious numbers of crinoid fragments of which it is usually composed, one cannot but regret that so very few complete specimens of the organisms have been preserved to us. This has always been a subject of lament to Scottish palæontologists. In the Carboniferous Limestones of Scotland, as a whole, cups even appear to be of rare occurrence, and judging from the lists of species hitherto published, and the specimens exhibited in our museums, they occur at widely-separated localities. Now, in Fife this is not the case, where, I am glad to say, it has been my good fortune to find several localities within a short distance of one another, where large numbers of cups and more or less entire specimens may be found. This is an interesting fact, for among the many classes of organisms which abound in our rocks there is, I think, no more beautiful object than a well-preserved crinoid—a specimen which always brings a thrill of joy and delight to the heart of its discoverer. If we examine the collections of Scottish Carboniferous fossils which are exhibited in our museums, the crinoids occupy but a small space compared with other classes. Further, if we note the lists of crinoid species from Scotland recorded in various publications, the total is by no means large. Scottish Carboniferous crinoid nomenclature is in a very unsatisfactory state at present, and when we remember that many of the This 250-word extract was created in the absence of an abstract