Explore the vast range of titles available.

Three new bibenzochromenones named phanogracilins A–C (1–3) were isolated from the crinoid Phanogenia gracilis. The structure of 1 was established using X-ray crystallography as 5,5′,6,6′,8,8′-hexahydroxy-2,2′-dipropyl-4H,4′H-[7,9′-bibenzo[g]chromene]-4,4′-dione. This allowed us to assign reliably 2D NMR signals for compound 1 and subsequently for its isomer 2 that differed in the connecting position of two benzochromenone moieties (7,10′ instead of 7,9′), and compound for 3 that differed in the length of the aliphatic chain of one of the fragments. Compound 4 was derived from 1 in alkaline conditions, and its structure was elucidated as 5,5′,6′,8,8′-pentahydroxy-2,2′-dipropyl-4H,4′H-[7,9′-bibenzo[g]chromene]-4,4′,6,9-tetraone. Even though compounds 1–4 did not contain stereo centers, they possessed notable optical activity due to sterical hindrances, which limited the internal rotation of two benzochromenone fragments around C(7)–C(9′/10′) bonds. Isolated bibenzochromenones 1–4 were tested for their antiradical, neuroprotective and antimicrobial activities. Compounds 1, 3 and 4 demonstrated significant antiradical properties towards ABTS radicals higher than the positive control trolox. Compounds 1 and 4 exhibited moderate neuroprotective activity, increasing the viability of rotenone-treated Neuro-2a cells at a concentration of 1 µM by 9.8% and 11.8%, respectively. Compounds 1 and 3 at concentrations from 25 to 100 μM dose-dependently inhibited the growth of Gram-positive bacteria S. aureus and yeast-like fungi C. albicans, and they also prevented the formation of their biofilms. Compounds 2 and 4 exhibited low antimicrobial activity.

Crinoid columnals are major faunal components of interbedded shales and carbonates of the Upper Ordovician Kope to Fairview formations (Edenian-Maysvillian) of the Cincinnati Arch region. Six species can be identified on the basis of distinctive morphological characters of the columnals. Crinoid distribution was plotted from point-counted carbonate samples taken through a 68-m thick composite section of the Kope to Fairview formations in Campbell County, Kentucky. This section spans a shallowing-upward, third-order depositional sequence (C1), part of C2, and the Edenian-Maysvillian Stage boundary. The slender cladid crinoid Merocrinus occurs in the lowermost Kope below the base of this section. The slender disparids Cincinnaticrinus and Ectenocrinus occur throughout the section but are most abundant in the lower 25 m where the shale percentage is 60-90 percent. The larger, more robust disparid Iocrinus appears within the carbonate-rich Grand Avenue member of the Kope at 40-50 m, and the large, plated camerate Glyptocrinus first appears just above the Grand Avenue and becomes the dominant crinoid above the C1-C2 sequence boundary that lies just above the Kope-Fairview contact. The largest and most robust crinoid in this sequence, Anomalocrinus, occurs at the top of the Grand Avenue Member. Siliciclastic ratio and biofacies composition indicate that the occurrence of larger, more robust crinoid taxa is correlated with shallowing depth. Crinoid trophic niche differentiation is also correlated with decreasing depth and the concomitant increase in water movement caused by waves and currents. The deeper water disparids have a nonpinnulate filtration fan with low branch density and wider ambulacral grooves. The shallower water camerate Glyptocrinus has a pinnulate filtration fan with high branch density and narrower ambulacral grooves. These relationships are consistent with the predictions of aerosol filtration theory.

Knowledge of phylogenetic relationships among species is fundamental to understanding basic patterns in evolution and underpins nearly all research programs in biology and paleontology. However, most methods of phylogenetic inference typically used by paleontologists do not accommodate the idiosyncrasies of fossil data and therefore do not take full advantage of the information provided by the fossil record. The advent of Bayesian ‘tip-dating’ approaches to phylogeny estimation is especially promising for paleosystematists because time-stamped comparative data can be combined with probabilistic models tailored to accommodate the study of fossil taxa. Under a Bayesian framework, the recently developed fossilized birth–death (FBD) process provides a more realistic tree prior model for paleontological data that accounts for macroevolutionary dynamics, preservation, and sampling when inferring phylogenetic trees containing fossils. In addition, the FBD tree prior allows for the possibility of sampling ancestral morphotaxa. Although paleontologists are increasingly embracing probabilistic phylogenetic methods, these recent developments have not previously been applied to the deep-time invertebrate fossil record. Here, I examine phylogenetic relationships among Ordovician through Devonian crinoids using a Bayesian tip-dating approach. Results support several clades recognized in previous analyses sampling only Ordovician taxa, but also reveal instances where phylogenetic affinities are more complex and extensive revisions are necessary, particularly among the Cladida. The name Porocrinoidea is proposed for a well-supported clade of Ordovician ‘cyathocrine’ cladids and hybocrinids. The Eucladida is proposed as a clade name for the sister group of the Flexibilia herein comprised of cladids variously considered ‘cyathocrines,’ ‘dendrocrines,’ and/or ‘poteriocrines’ by other authors.

A major goal of biological classification is to provide a system that conveys phylogenetic relationships while facilitating lucid communication among researchers. Phylogenetic taxonomy is a useful framework for defining clades and delineating their taxonomic content according to well-supported phylogenetic hypotheses. The Crinoidea (Echinodermata) is one of the five major clades of living echinoderms and has a rich fossil record spanning nearly a half billion years. Using principles of phylogenetic taxonomy and recent phylogenetic analyses, we provide the first phylogeny-based definition for the Clade Crinoidea and its constituent subclades. A series of stem- and node-based definitions are provided for all major taxa traditionally recognized within the Crinoidea, including the Camerata, Disparida, Hybocrinida, Cladida, Flexibilia, and Articulata. Following recommendations proposed in recent revisions, we recognize several new clades, including the Eucamerata Cole 2017, Porocrinoidea Wright 2017, and Eucladida Wright 2017. In addition, recent phylogenetic analyses support the resurrection of two names previously abandoned in the crinoid taxonomic literature: the Pentacrinoidea Jaekel, 1918 and Inadunata Wachsmuth and Springer, 1885. Last, a phylogenetic perspective is used to inform a comprehensive revision of the traditional rank-based classification. Although an attempt was made to minimize changes to the rank-based system, numerous changes were necessary in some cases to achieve monophyly. These phylogeny-based classifications provide a useful template for paleontologists, biologists, and non-experts alike to better explore evolutionary patterns and processes with fossil and living crinoids.

The phylum Echinodermata comprising the classes Asteroidea, Ophiuroidea, Echinoidea, Holothuroidea, and Crinodeia, is one of the important invertebrate groups. Members of this phylum live exclusively in marine habitats and are distributed in almost all depths and latitudes. Some of them, such as sea urchins and sea cucumbers, are commercially valuable and constitute a major fishery resource. Echinoderms are increasingly recognized as a unique source of various metabolites with a wide range of biological activities. The importance of dietary polyunsaturated fatty acids, such as eicosapentaenoic acid, in human health has drawn attention to echinoderms as a promising source of essential fatty acids (FAs). Extensive information on the FAs of the phylum has been accumulated to date. The biosynthetic capabilities and feeding habits of echinoderms explain the findings of the unusual FAs in them. Certain common and unusual FAs may serve as chemotaxonomic markers of the classes. The main goal of the review was to gather the relevant information on the distribution of FAs among the echinoderm classes, describe the structures, distribution, biosynthetic pathways, and bioactivity, with an emphasis on the FAs specific for echinoderms. A large part of the review is devoted to the FAs derived from echinoderms that exhibit various biological activities promising for potential therapeutic applications.

Two cupressocrinitids (Crinoidea, Eucladida) from the famous crinoid collection of Dr. Ludwig J.T. Schultze deposited in the Museum of Comparative Zoology (MCZ) are revised in the present study: Cupressocrinites hybridus n. comb. and Halocrinites minor n. comb. The rare C. hybridus has a stratigraphically and regionally restricted occurrence at the Eifelian–Givetian boundary of the Hillesheim Syncline (Eifel, Rhenish Massif, Germany), but the more common H. minor occurs supraregionally from the Eifelian to the Frasnian (Middle to Upper Devonian). Both cupressocrinitids are redescribed on the basis of the type material stored in the MCZ. In addition, the rare Halocrinites heinorum n. sp. from the Eifelian–Givetian boundary beds and lower Givetian of the Eifel (Rhenish Massif, Germany) is described, and Encrinus townsendi (König, 1825) is questionably reassigned to Robustocrinites: R.(?) townsendi n. comb. Pre- and postmortem ossicular modifications of the studied cupressocrinitid skeletons are also discussed.

Development of a phylogenetic classification has been a primary pursuit of crinoid paleontologists during the 20th century. Wachsmuth and Springer and Bather vigorously debated crinoid classification during the waning years of the 19th century, and although tremendous progress has been made a comprehensive phylogenetic classification is still the primary objective for crinoid research during the early 21st century. Twentieth century crinoid studies are divisible into four periods. The direct influence of Frank Springer and Francis Bather continued until approximately 1925. Descriptive studies dominated the period of 1926-1943 and culminated in a comprehensive classification of Paleozoic crinoids that was a combination of the ideas of Wachsmuth and Springer and Bather. The end of the third period, 1944-1978, was marked by publication of the Treatise on Invertebrate Paleontology. The Treatise compilation brought together classification ideas for the entire class into a truly comprehensive classification, although problems remained with the phylogenetic underpinnings of the Treatise classification. During the third period, pioneering work on crinoid paleobiology laid the foundation for significant paleobiology advances for the fourth, 1979-1999, period. This last period also witnessed significant advances in the taxonomy of crinoid faunas at critical intervals, the taxonomy of crinoids from new geographic areas, and working toward the solution to the origin and early evolution of the Crinoidea. Continued work on crinoids in the 21st century promises to provide significant advances both for understanding the evolutionary history of crinoids and for understanding the history of epifaunal benthic communities through time. Immediate challenges include completion of a comprehensive phylogenetic classification, which will open the door for evolutionary paleoecologic and paleobiologic studies; utilization of computerized morphometric techniques in the analysis of functional morphology; systematic studies of new faunas in critical intervals; discovery of faunas in new geographic areas to better constrain knowledge of crinoid biogeography; and modern systematic revision of classic North American and European faunas.

Gennaeocrinus tariatensis new species is an Emsian (Devonian) monobathrid crinoid described from the Tarvagatay Terrane of Mongolia and part of the Central Asian Orogenic Belt. The Tarvagatay Terrane is an arc terrane that accreted to the southern margin of the Siberian Craton. Gennaeocrinus tariatensis was collected from the Emsian Tariat Formation, a terrigenous sequence of conglomerates, sandstones, and siltstones. Associated faunas include brachiopods, molluscs, and rare tabulate corals. Although Gennaeocrinus is well known from the Emsian–Givetian of North America, this is the first occurrence of the genus outside Laurussia. Mongolia is a large country with many terranes having varied paleogeographic, sedimentological, and tectonic histories; but reports of Paleozoic echinoderms are rare. The crinoid occurrence from the Tariat Formation is from the same age as previously described Emsian crinoids from the Chuluum Formation but differs significantly in sedimentology, paleogeography, and paleolatitude.

The cladid crinoid order Poteriocrinida Jaekel, 1918 is a polyphyletic group that includes a variety of independent lineages united solely by the presence of ramulate or pinnulate arms. One of these lineages is the Rutkowskicrinidae new family herein assigned to the order Dendrocrinida. Bather 1899. Genera assigned to this new family include Rutkowskicrinus new genus, Decorocrinus new genus, Iteacrinus, Nassoviocrinus, Quantoxocrinus, Sacrinus, Sostronocrinus, ?Propoteriocrinus, and ?Schmidtocrinus. Members of this family are characterized by low conical cups with ridged thecal plates. U-shaped peneplenary radial facets bearing faint transverse ridges, a proximal median ridge on the posterior side of a long, narrow, predominantly straight anal sac, and pentagonal columns with one to two cirri per nodal. Arms in this family are highly variable, ranging from isotomous to heterotomous and pinnulate. The arms in the type specimen of Rutkowskicrinus patriciae n. sp. preserve all these various arm stages. The oldest presently known rutkowskicrinids occur in the Late Silurian (Ludlovian) of Australia and the Early Devonian (Pragian) of western Europe. The family diversified during the Middle Devonian (Givetian) in northeastern North America, and declined in numbers and diversity throughout the Late Devonian before going extinct in the Early Mississippian (Tournaisian). The Glossocrinidae Goldring, 1923, containing Glossocrinus, Charientocrinus, Catactocrinus, and Liparocrinus, is also reviewed. This family, distinguished by a strongly recumbent anal sac in the B-E plane and a prominent median ridge extending the entire length of the anal sac, was derived from the Rutkowskicrinidae during the Middle Devonian (Givetian) and diversified in the Late Devonian before going extinct at the Frasnian-Famennian boundary. The previously described rutkowskicrinid and glossocrinid genera listed above were assigned by Moore et al. (1978) to the dendrocrinid family Mastigocrinidae and poteriocrinid families Rhenocrinidae, Poteriocrinitidae, and Scytalocrinidae. Studied taxa include Rutkowskicrinus patriciae new genus and species, Rutkowskicrinus collieri new genus and species, Nassoviocrinus costatus new combination, Nassoviocrinus schultzei new combination, Nassoviocrinus? duluki new combination, Nassoviocrinus? ornatus new combination, Nassoviocrinus? chilmanae new species, Decorocrinus arkonensis new combination, Decorocrinus cooperi new combination, Quantoxocrinus clarkei new combination, Glossocrinus halli new combination, and Charientocrinus bellitubatus new combination.

In A recently published account of Middle Triassic crinoids from southwest China, Stiller (2000, p. 33) made a number of general points concerning the classification of crinoids on the basis of their disarticulated ossicles. Donovan (1986) was attributed with proposing the suffix (col.) (not (col) as quoted by Stiller) for use with crinoid genera based solely on elements of the column; it was suggested that (col.) had not been generally accepted and had only rarely been used in publications; Stiller regarded the approach as \"not convincing,\" as other groups of organisms preserved as disarticulated elements are successfully classified without resorting to such suffixes; it was rightly considered that systematists should attempt to place new taxa within a more or less \"natural\" system; and Stiller regarded the use of suffixes as questionable with respect to the International Code of Zoological Nomenclature. This analysis invites further discussion on an area of systematic paleontology that continues to be underexplored. The purpose of this note is to further examine these ideas and to discuss some of the difficulties of classifying Paleozoic pelmatozoans on the basis of their disarticulated columnals.