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Text-fig. 6. a. Vertical section showing part of body-chamber of a Cenoceras in the top of the Main Cenoceras Bed associated with attached oysters below and stringers of crinoid debris below and stretching laterally. Coin 23 mm in diameter. b. Complete lateral half of conch showing intact and elastically deformed septa on which rests crinoid debris that spreads across the exposed septa and onto the adjacent substrate. Conch approximately 180 mm in diameter. c. Individual showing dispersed crinoid and molluscan debris within body-chamber and septa in the crushed inner whorls that have taken a sparite cement prior to, and after having undergone brittle deformation. 160 mm in diameter. d. Vertically embedded specimen showing the loss of septa in the inner whorls that are infilled with matrix mottled by bioturbation. Tape measure provides scale. in 'Cenoceras Islands' In The Blue Lias Formation (Lower Jurassic) Of West Somerset, Uk: Nautilid Dominance And Influence On Benthic Faunas

Text-fig. 6. a. Vertical section showing part of body-chamber of a Cenoceras in the top of the Main Cenoceras Bed associated with attached oysters below and stringers of crinoid debris below and stretching laterally. Coin 23 mm in diameter. b. Complete lateral half of conch showing intact and elastically deformed septa on which rests crinoid debris that spreads across the exposed septa and onto the adjacent substrate. Conch approximately 180 mm in diameter. c. Individual showing dispersed crinoid and molluscan debris within body-chamber and septa in the crushed inner whorls that have taken a sparite cement prior to, and after having undergone brittle deformation. 160 mm in diameter. d. Vertically embedded specimen showing the loss of septa in the inner whorls that are infilled with matrix mottled by bioturbation. Tape measure provides scale.

Text-fig. 7. a. Worn section through a horizontally bedded body-chamber and phragmocone, body-chamber showing oyster attached to inside of aperture as well as burrow mottling. Tape measure provides scale. b. Body-chamber and crushed phragmocone with body-chamber and phragmocone entirely filled with bioturbated matrix containing stringers of crinoid and molluscan debris. Flank of phragmocone encrusted by oysters. Tape measure for scale. c. Complex of Thallassinoides and Diplocraterion burrows associated with conch that has been eroded out by wave action. A few 'Ghostly' fragments of ammonite are also present. Original scope of the image approximately 400 mm. c. Verically embedded conch with largely intact septa and camera infilled with burrowed matrix containing crinoid debris. Tape measure for scale. in 'Cenoceras Islands' In The Blue Lias Formation (Lower Jurassic) Of West Somerset, Uk: Nautilid Dominance And Influence On Benthic Faunas

Text-fig. 7. a. Worn section through a horizontally bedded body-chamber and phragmocone, body-chamber showing oyster attached to inside of aperture as well as burrow mottling. Tape measure provides scale. b. Body-chamber and crushed phragmocone with body-chamber and phragmocone entirely filled with bioturbated matrix containing stringers of crinoid and molluscan debris. Flank of phragmocone encrusted by oysters. Tape measure for scale. c. Complex of Thallassinoides and Diplocraterion burrows associated with conch that has been eroded out by wave action. A few 'Ghostly' fragments of ammonite are also present. Original scope of the image approximately 400 mm. c. Verically embedded conch with largely intact septa and camera infilled with burrowed matrix containing crinoid debris. Tape measure for scale.

Text-fig. 8. a. Shell belonging to one flank of the conch a horizontally bedded individual with sveral large oysters attached to its underside indicating that the shell was either originally vertical or was flipped from one surface to the other by turbulance. Approximately 300 mm across. b. Crushed individual showing oysters encrusting both flanks of the conch. 250 mm in diameter. c. Wave-worn conch showing oysters attached to the umbilicus, the venter and possibly the inside of the body-chamber. Tape measure for scale. d. Flank of conch with crinoid debris and oysters spread around its periphery. Scope of image approximately 350 mm. in 'Cenoceras Islands' In The Blue Lias Formation (Lower Jurassic) Of West Somerset, Uk: Nautilid Dominance And Influence On Benthic Faunas

Text-fig. 8. a. Shell belonging to one flank of the conch a horizontally bedded individual with sveral large oysters attached to its underside indicating that the shell was either originally vertical or was flipped from one surface to the other by turbulance. Approximately 300 mm across. b. Crushed individual showing oysters encrusting both flanks of the conch. 250 mm in diameter. c. Wave-worn conch showing oysters attached to the umbilicus, the venter and possibly the inside of the body-chamber. Tape measure for scale. d. Flank of conch with crinoid debris and oysters spread around its periphery. Scope of image approximately 350 mm.

Text-fig. 9. a. Shorn-off, vertically embedded conch surrounded by layer of crinoid debris at level of planation of shell and with some debris within the conch at this level. Lateral width of body-chamber 80 mm. b. Example of ammonite that occurs rarely in the Main Cenoceras Bed. Note the poorly defined shell particularly on the outer whorl, suggesting partial dissolution. Tape measure for scale. in 'Cenoceras Islands' In The Blue Lias Formation (Lower Jurassic) Of West Somerset, Uk: Nautilid Dominance And Influence On Benthic Faunas

Text-fig. 9. a. Shorn-off, vertically embedded conch surrounded by layer of crinoid debris at level of planation of shell and with some debris within the conch at this level. Lateral width of body-chamber 80 mm. b. Example of ammonite that occurs rarely in the Main Cenoceras Bed. Note the poorly defined shell particularly on the outer whorl, suggesting partial dissolution. Tape measure for scale.

Fig. 7 in Epibionts on upper Eifelian crinoid columnals from the Holy Cross Mountains, Poland

Fig. 7. Frequency distribution of epibionts on the crinoid host species from the Skały Beds (upper part of complex XVII, Tortodus kockelianus Zone), Skały village, Holy Cross Mountains; e, number of epibionts; h, number of hosts.

Fig. 3 in Epibionts on upper Eifelian crinoid columnals from the Holy Cross Mountains, Poland

Fig. 3. Epibionts on crinoids from the Skały Beds (upper part of complex XVII, Tortodus kockelianus Zone), Skały village, Holy Cross Mountains. A, B. Rhomboporid? bryozoan bases on Schyschcatocrinus creber Dubatolova, 1975; perpendicular orientation of the zoaria to the axis of stalk may indicate that the host was dead during epibiont growth. A. Regularly developed base, GIUS−4−2445/58. B. Root−like base, GIUS−4−2445/59. C–H. "Ctenostome bryozoans" encrusting nearly the entire circumference of columnals that may indicate that the stalks were upright when fouled. C. Eliasopora stellata (Nicholson and Etheridge, 1877) on Tantalocrinus scutellus Le Menn, 1985, GIUS−4−2445/27. D. "Ropalonaria" givetiana Kiepura, 1965 on Schyschcatocrinus creber Dubatolova, 1975; arrows indicate small borings of Trypanites?, GIUS−4−2445/31. E. Allonema moniliforme parvum Kiepura, 1965 on Tantalocrinus scutellus Le Menn, 1985, GIUS−4−2445/15. F. Ascodictyon vinelliforme Kiepura, 1965 on Pentagonostipes petaloides Moore and Jeffords, 1968, GIUS−4−2445/21. G. Ascodictyon sparsiforme Kiepura, 1965 (white arrows) and Vinella sp. (black arrow) on Cycloocetocrinus sp., GIUS−4−2445/17. H. Vinella sp. on Cycloocetocrinus sp., GIUS−4−2445/34. Scale bars 1 mm.

Fig. 4 in Epibionts on upper Eifelian crinoid columnals from the Holy Cross Mountains, Poland

Fig. 4. Epibionts on crinoids from the Skały Beds (upper part of complex XVII, Tortodus kockelianus Zone), Skały village, Holy Cross Mountains. A. Cystoporate bryozoan Fistulipora sp. on Schyschcatocrinus creber Dubatolova, 1975; growth around the entire stem circumference may indicate that the host was alive, GIUS−4−2445/53. B–E. Cystoporate bryozoan Eridopora orbiculata (Kiepura, 1973) on Pentagonostipes petaloides Moore and Jeffords, 1968 (B–D) and Tantalocrinus scutellus Le Menn, 1985 (E). B. Growth around the entire stem circumference may indicate that the host was alive, GIUS−4−2445/45. C. Growth on one side of the stem may indicate that the host was dead, GIUS−4−2445/46. D. Arrow indicates small "ctenostome bryozoan" Ascodictyon vinelliforme Kiepura, 1965, GIUS−4−2445/47. E. Arrow indicates damaged and regenerated part of the stem, GIUS−4−2445/48. F–H. "Cyclostome bryozoan" Hederella sp. on Tantalocrinus scutellus Le Menn, 1985 (F) and Pentagonostipes petaloides Moore and Jeffords, 1968 (G, H); zoaria occupying a significant part of the columnals circumference may indicate that they lived on the upright stalks. F. Zoarium on well ornamented, circular pluricolumnal, GIUS−4−2445/37. G. Zoarium on angularly pentagonal pluricolumnal, GIUS−4−2445/38. H. Zoarium on subpentagonal pluricolumnal, GIUS−4−2445/39. Scale bars 1 mm.

Fig. 2 in Epibionts on upper Eifelian crinoid columnals from the Holy Cross Mountains, Poland

Fig. 2. Epibionts on crinoids from the Skały Beds (upper part of complex XVII, Tortodus kockelianus Zone), Skały village, Holy Cross Mountains. A. Saccamminid foraminiferans on Gilbertsocrinus vetulus Moore and Jeffords, 1968, GIUS−4−2445/3. B, C. Schyschcatocrinus creber Dubatolova, 1975 malformed by attachment of the brachiopod Poloniproductus? sp.; stereomic overgrowth indicates that the host was alive when fouled. B. Root appendage, GIUS−4−2445/11. C. Stem fragment, GIUS−4−2445/12. D. Cyrtinitid brachiopod on Tantalocrinus scutellus Le Menn, 1985, GIUS−4−2445/14. E, F. Rugose coral Adradosia? sp. on Schyschcatocrinus creber Dubatolova, 1975; stereomic response indicates that both epibionts and the hosts were alive contemporaneously. E. Arrows indicate later attachment of juvenile crinoids (holdfasts), GIUS−4−2445/4. F. Cluster of three individuals; note significant stereomic overgrowth (F1) and complete boreholes (Trypanites?) on coral on opposite side of pluricolumnal (F2), GIUS−4−2445/5. G. Tabulate coral Favosites sp. on Tantalocrinus scutellus Le Menn, 1985; oblique orientation of the coral may indicate that the crinoid stalk was upright during epibiont growth, GIUS−4−2445/9. Scale bars 1 mm.

Fig. 1 in Epibionts on upper Eifelian crinoid columnals from the Holy Cross Mountains, Poland

Fig. 1. Geological map of western part of the Holy Cross Mountains and location of study site. Simplified after Marynowski et. al. (2000).

publicSep 2019View details →

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Data from: Early Silurian recovery of Baltica crinoids following the end-Ordovician extinctions (Llandovery, Estonia)

Open the record for dataset details and reuse information.

opencc-zeroJul 2020View details →

A Hirnantian holdover from the late Ordovician mass extinction: phylogeny and biogeography of a new Anthracocrinid crinoid from Estonia

Relatively few Hirnantian (Late Ordovician) crinoids are known, and none have been previously described from the palaeocontinent of Baltica. This has impaired our ability to understand patterns of extinction and biogeographic dispersal surrounding the Late Ordovician mass extinction, which triggered a major turnover in crinoid faunas. Here, we describe Tallinnicrinus toomae gen. et sp. nov., an anthracocrinid diplobathrid from the Hirnantian of northern Estonia. Tallinnicrinus is the youngest member of the Anthracocrinidae and the first representative of the family to occur in Baltica. Morphologically, Tallinnicrinus is unusual in that the radial and basal plates are in a single circlet of ten plates, similar to the anthracocrinid Rheocrinus Haugh, 1979 from the Katian of Laurentia. Phylogenetic analysis further confirms a close relationship between Tallinnicrinus and Laurentian anthracocrinids, suggesting biogeographic dispersal of the lineage from Laurentia to Baltica during the late Katian or early Hirnantian. The occurrence of this new taxon establishes that the family Anthracocrinidae survived the first pulse of the Late Ordovician mass extinction. However, the lineage remained a "dead clade walking" as it failed to diversify in the wake of the end-Katian extinction and ultimately went extinct itself by the end of the Ordovician.

opencc-zeroNov 2019View details →

Data from: The nervous and circulatory systems of a Cretaceous crinoid: preservation, paleobiology, and evolutionary significance

Featherstars, those comatulid crinoids that shed their stalk during their ontogeny, are the most species-rich lineage of modern crinoids and the only ones present in shallow water today. Although they are of considerable paleontological interest as a 'success story' of the Mesozoic Marine Revolution, their fossil record is relatively species-poor and fragmentary. New Spanish fossils of the Cretaceous featherstar Decameros ricordeanus preserve the shape and configuration of nervous and circulatory anatomy in the form of infilled cavities, which we reconstruct from CT scans. The circulatory system of D. ricordeanus was relatively extensive and complex, implying a pattern of coelomic fluid flow that is unique among crinoids, and the peripheral parts of the nervous system include linkages both to the circulatory system and to the surface of the body. A phylogenetic analyses – the first to include both living and fossil featherstars and which includes characters from internal anatomy – recovers D. ricordeanus among the lineage of featherstars that includes Himerometroidea, Tropiometra, and "Antedonoidea," among others. D ricordeanus is larger than almost any modern featherstar, and its elaborate coelomic morphology appears to be a consequence of positive allometry. All featherstars with coelomic diverticula are shown to belong to a single comatulid subclade, and this feature may constitute a synapomorphy of that group. Some preservation of cavities corresponding to soft tissue is probably not exceptional in fossil crinoids, providing an opportunity to study the diversity and evolution of extinct anatomical systems typically only preserved in Lagerstätten.

opencc-zeroJan 2020View details →

Data from: Fullerene-like structures of Cretaceous crinoids reveal topologically limited skeletal possibilities

In general there are few cases where numbers or types of possible phenotypes are known, although vast state spaces have been postulated. Rarely applied in this context, graph theory and topology enable enumeration of possible phenotypes and evolutionary transitions. Here, we generate polyhedral calyx graphs for the Late Cretaceous, stemless crinoids Marsupites testudinarius and Uintacrinus socialis (Uintacrinoidea Zittel 1879) revealing structural similarities to carbon fullerenes and fulleroids (respectively). The Uintacrinus calyx incorporates numerous plates (e.g. |V| ≥ 197), which are small, light, low-density and have 4 to 8 sides. Therefore, the corresponding number of possible plate arrangements, given by the number of polyhedral graphs, is large (>> 〖1×10〗^14). Graph vertices representing plates with sides > 6 introduce negative Gaussian curvature and topological instability. However, observed Uintacrinus graph cardinalities (|V|) do not allow more stable pentaradial configurations. In contrast, the Marsupites calyx dual graph has 17 faces that are pentagonal or hexagonal. Therefore, it is structurally identical to a carbon fullerene, specifically C30-D5h. Corresponding graph restrictions result in radical constraint to only three structural options. Further restriction to pentaradial symmetry allows only one possibility: the Marsupites phenotype. This robust, stable topology is consistent with adaptation to the predation pressures of the Mesozoic marine revolution. Consequently, the most plausible evolutionary pathway between unitacrinoid phenotypes was a mixed heterochronic trade-off to fewer, larger calyx plates. Therefore, topological limitations radically constrained uintacrinoid skeletal possibilities but thereby aided evolution of a novel adaptive phenotype.

opencc-zeroMar 2016View details →

Crinoids

ID no.: no inventory number Museum: The Geological Museum at the Faculty of Geology, Geophysics and Environmental Protection of the AGH University of Science and Technology https://muzea.malopolska.pl/en/objects-list/834 Digitalisation: RDW MIC, Małopolska's Virtual Museums project Source: Objaverse 1.0 / Sketchfab

opencc-zeroDec 2020View details →

Crinoid

Crinoids (Crinoidea, Greek: krinon – lily + eidos - shape) are aquatic animals classified as echinoderms (Echinodermata). Their structure resembles flowers, hence their name. The presented Encrinus liliiformis is the most common crinoid of the upper shell limestone, i.e. an informal Triassic stratigraphic unit isolated in Poland, Germany and the Benelux. This species has been frequently described in the Tatra Mountains by Uhlig (1897), Rabowski (1959), Kotoński (1963) and Passendorfer (1983). The presented exhibit is a gift from Prof. Jerzy Lefeld, an outstanding researcher of the Tatra crinoids. ID no.: G/60/MT Time and place of creation: Triassic (middle triassic) Museum: The Dr. Tytus Chałubiński Tatra Museum in Zakopane https://muzea.malopolska.pl/en/objects-list/1821 Digitalisation: RDW MIC, Virtual Małopolska project Source: Objaverse 1.0 / Sketchfab

opencc-by-4.0Apr 2019View details →

Figure 1 in New records of the shrimp Periclimenes crinoidalis Chace, 1969 (Decapoda: Palaemonidae) and its crinoid host Nemaster grandis A.H. Clark, 1909 (Echinodermata: Crinoidea) in the Caribbean Sea

Figure 1. Crinoid Nemaster grandis, in Chichiriviche de la Costa, Vargas State.

opencc-zeroJun 2022View details →

Dispersals from the West Tethys as the source of the Indo-West Pacific diversity hotspot in comatulid crinoids

Conspicuous centers of biodiversity are frequently attributed to local conditions that promote speciation or resistance to extinction, but recent diversification studies indicate this mode of explanation might not be very general, so it may be fruitful to revisit the role of dispersal in concentrating biodiversity. Here we consider the processes underlying the marine diversity hotspot in the Indo-West Pacific among comatulid crinoids, suspension-feeding echinoderms conspicuous on modern tropical reefs. We used ancestral range reconstruction on a phylogeny of extant crinoids, assembled a new occurrence database of fossil comatulids and interrogated it with probabilistic preservational models, and developed a morphological character matrix to estimate the relationships among living and fossil comatulids. Ancestral range reconstruction on a phylogeny of extant comatulids recovers an origin outside the Indo-Pacific and elevated dispersal into it. A new occurrence database records the comatulid clade spreading out gradually from origin in the Early Jurassic of the West Tethys. They do not appear in their modern hotspot until the Oligocene, and taphonomic analyses show these results cannot be explained solely as a result of inadequate sampling in Asia and Oceania. Finally, phylogenetic analyses demonstrate that deeply nested crown-group comatulids had originated before the clade became well-established in the East Tethys, implying many independent dispersals into the modern hotspot. These consilient results suggest a biodiversity hotspot that owes its existence to dispersals out of the ancient West Tethys rather than to elevated in situ diversification.

opencc-by-4.0Aug 2006View details →

Fig. 10 in Description Of Crinotonia Anastasiae, New Genus, New Species, A New Crinoid Associated Pontoniine Shrimp (Crustacea: Caridea) From Nha Trang Bay, Vietnam, With Inclusion Of Periclimenes Attenuatus Bruce, 1971, In The New Genus

Fig. 10. Crinotonia attenuatus (Bruce), new combination, male (PCL 3.2 mm). Scale bar = 5 mm.

opencc-by-4.0Aug 2005View details →

Figure 21 in Environmental control versus phylogenic fingerprint in ontogeny: The example of the development of the stalk in the genus Guillecrinus (stalked crinoids, Echinodermata)

Figure 21. Comparison of the filtration potential of the crown in several extant stalked crinoids.