Radial Facets Research Articles

New specimens of Cyclocystoides scammaphoris (Echinodermata) from the Upper Ordovician rocks of the American midcontinent with implications for cyclocystoid functional morphology

AbstractNew specimens of Cyclocystoides scammaphoris Smith and Paul, 1982, are here reported from the Upper Ordovician Platteville Formation of northern Illinois, Plattin and Decorah groups of east-central Missouri, and Lebanon Limestone of central Tennessee. These fossils reveal skeletal details that provide insight into the anatomy of cyclocystoids. Of particular significance is a network of channels that likely originate near the center of the central disk and extend along the oral side of the radial plates, bifurcating distally two or three times before entering the radial facets on the proximal surface of each marginal ossicle. From here, the network enters a series of facet canals that extend upward through each marginal ossicle, exiting in a linear row of pores. The canals are very similar in size and distribution to the nerve canals in living echinoderms. The axes of the canals, which number up to 500 in some specimens, and those of the radial ducts project proximally away from the oral surface at an elevation angle of about 25°, apparently forming a network that could have converged within the upper part of the body cavity. This origin and function are made clear by the connection between the channel on each radial plate and the radial facet canal pores within each marginal ossicle.

A possible crawling paracomatulid crinoid from the Lower Jurassic of central Italy

A new paracomatulid crinoid, Tiburtocrinus toarcensis gen. et sp. nov., is described from the Lower Jurassic of Tivoli (central Apennines, Italy). This type of stemless crinoids has never previously been recorded in Italy, and this report bridges a significant gap. Morphofunctional analysis of the radial facets suggests that Tiburtocrinus toarcensis gen. et sp. nov. may have been a crawling paracomatulid, very different from other paracomatulids that probably swam.

Light-driven complex 3D shape morphing of glassy polymers by resolving spatio-temporal stress confliction

Programmable 3D shape morphing of hot-drawn polymeric sheets has been demonstrated using photothermal local shrinkage of patterned hinges. However, the hinge designs have been limited to simple linear hinges used to generate in-plane local folding or global curvature. Herein, we report an unprecedented design strategy to realize localized curvature engineering in 3D structures employing radial hinges and stress-releasing facets on 2D polymeric sheets. The shape and height of the 3D structures are readily controlled by varying the number of radial patterns. Moreover, they are numerically predictable by finite elemental modeling simulation with consideration of the spatio-temporal stress distribution, as well as of stress competition effects. Localized curvature engineering provides programming capabilities for various designs including soft-turtle-shell, sea-shell shapes, and saddle architectures with the desired chirality. The results of local curvilinear actuation with quantifiable stress implies options to advance the applicability of self-folded architectures embodying coexisting curved and linear geometric surfaces.

Understanding the Radiographic Anatomy of the Proximal Ulna and Avoiding Inadvertent Intraarticular Screw Placement

To map the proximal ulnar articular margins and ensure safe extraarticular placement of implants. Ten fresh frozen adult elbow cadaver specimens were obtained. Radiopaque wire was applied to the articular margin of the articular facets and the central trochlear ridge of the proximal ulna. Fluoroscopic images were obtained demonstrating the articular facet margins. Radiographic measurements were performed and used to identify relative safe screw zones. All specimens demonstrated marked extension of the ulnar and radial facets dorsal to the central trochlear ridge. The dorsal extent of the ulnar facets from the central trochlear ridge averaged 9.7 mm (range, 7.9-13 mm; SD, 1.5 mm) and 6.2 mm (range, 3.4-9.4 mm; SD, 1.9 mm), respectively. The average footprint of the posterior ulnar facet occupied 44% (±4.9%) of the total ulnar height from the dorsal cortex to the trochlear ridge. The articular margins of the anterior and posterior facets of the proximal ulna are challenging to identify radiographically. A surgical "at-risk zone" exists within 9.7 mm from the radiographic margin of the central trochlear ridge. Implants placed within this zone have the potential to violate the articular surface.

Qualitative Structural Theory: A Basis for Decision-Making

The development of analyses of qualitative data that reveal their underlying structure, using the facet framework, are reviewed in the present article. These provide the basis for a general theory of the inherent structure of most qualitative data, an aspect that other approaches typically only allow for with quantitative data. This broadens the application of Facet Theory beyond its usual remit with quantitative measures. It also provides a conceptual model, or “theory,” that combines ordered (modulating) and non-ordered (radial) facets for many different contexts. Results from “qualitative structural theory” (QST) are shown to be open to interpretation as a form of Narrative Action System. Although the power of QST has been illustrated in many areas, in this article three contrasting areas of application are discussed, which each uses a different form of non-metric multidimensional scaling (MDS). One is the exploration of variation in the actions of arsonists revealed through Smallest Space Analysis (SSA). A second is the modeling of consumer choice of chocolates using Multidimensional Scalogram Analysis (MSA). The third is the differentiation of genuine and false claims of rape using Partial Order Scalogram Analysis by Co-ordinates (POSAC). The practical implications of these QST models to assist decision making are briefly discussed.

Advancement of Criminal Profiling Methods in Faceted Multidimensional Analysis

AbstractThe current study seeks to advance the faceted multidimensional scaling (termed FMDS) procedure used in much of the investigative psychology research. To this end, recent research on street robbery by Goodwill and colleagues will be utilised to illustrate the effectiveness of a facet scale method for offender profiling. Four FMDS themes of street robbery (Con, Blitz, Confrontation and Snatch) were revealed by the crossing of two underlying axial facets: the offenders' level of violence and interaction with the victim. The facet scale method, utilising offenders' axial facet scores, was compared to previous count, proportional and centroid classification methods in the prediction of offender criminal histories. Utilising logistic regression and receiver operating characteristic analyses, the axial facet scale method was found to significantly outperform the qualitatively based dominant theme classification methods that typically employ angular and radial facets for FMDS interpretation. Implications for the use of axial facet scales within FMDS analysis for offender profiling research are discussed. Copyright © 2012 John Wiley & Sons, Ltd.

Revision of two species of ?Ulocrinus and a new pelecocrinid crinoid from West Timor

Two cladid crinoid species, ?Ulocrinus indicusWanner, 1924, and ?Ulocrinus conoideusWanner, 1937, are reinterpreted as cladid crinoids that do not belong to the cromyocrinids. This justifies Wanner's questioning of the generic assignment. ?Ulocrinus indicus has bifascial radial facets and is considered an advanced intermediate dendrocrinid assigned to the incertae superfamiliae, Katerocrinidae n. fam., Katerocrinus indicus n. gen., n. comb. This extends the range of the bifascial dendrocrinids upward into the Permian. ?Ulocrinus conoideus has trifascial radial facets and is assigned to the superfamily Scytalocrinoidea, incertae familiae, Dochmocrinus conoideus n. gen., n. comb. It re-emphasizes the need for revision of the family Scytalocrinidae. An unnamed, poorly preserved cup is described and considered to be a pelecocrinid crinoid, thus adding to the diversity of the West Timor Permian crinoids.

Triassic: the crucial period of post-Palaeozoic crinoid diversification

After their near-extinction around the end of the Permian, crinoids recovered during the Triassic and re-occupied almost all ecological niches they had held in Palaeozoic times. Triassic crinoids comprise 33 genera in 12 well-defined families and 5 orders of the subclass Articulata; the systematic position of 4 additional families is unknown. The highest diversity was before the Mid Carnian Wet Intermezzo that caused the extinction of the order Encrinida. Major morphologic changes were connected with the adaptation to various benthic habitats and to pseudoplanktonic and eleutherozoic modes of life. Convergently, the cups of Encrinida and Holocrinida–Isocrinida became cryptodicyclic with large muscular radial facets, arm numbers increased from 5 to more than 300, and the arms of Encrinida became gradually biserial. The Encrinida remained permanently fixed to hardgrounds and acted as frame builders in bioherms. By encrusting bivalve mudstickers some dadocrinids also became secondary soft bottom dwellers. The holocrinid stem evolved preformed rupture points at the lower nodal facets, allowing these crinoids to attach intermittently by cirri. The pseudoplanktonic traumatocrinids evolved extremely long, flexible stems with multiple pore systems and terminal root cirri. Paracomatulids and eocomatulids reduced their stems and adapted to an eleutherozoic mode of life. Somphocrinids miniaturized and remodeled their skeleton towards lightweight construction and adapted to a planktonic life style. After the Triassic no fundamentally novel adaptation was added. Crinoidal limestones, as common in the Palaeozoic, had their last appearance in Middle Triassic times.

Inplenary and explenary radial facets in cladid crinoids

Three types of radial facets have been recognized in the cladid crinoids. These are: • Angustary—the facet occupies less than 70% of the width of the distal end of the radial. • Peneplenary—the facet occupies between 70% and 99% of the width of the distal end of the radial. • Plenary—the facet occupies the full width of the radial facet. Both the angustary and peneplenary radial facets have interradial notches between adjacent radial facets along the sutures on the distal ends of the radials. The radial facets are here referred to as inplenary if an interradial notch (here referred to as exinterradial notch) is between the distal ends of the transverse ridges and the aboral parts of the muscle fields are abutting at the suture. If the interradial notch is between the muscle fields and the distal ends of the transverse ridges are abutting, then the radial facet is referred to as explenary and the notch as ininterradial. The origin of these conditions is uncertain. However, they may be an evolutionary transition between the peneplenary and plenary conditions or they may be a secondary response to evolutionary changes in the cup structure. The explenary radial facets may have resulted in minimal contact of the primibrachials when opening, closing, or manipulating the arms. It is here proposed that the interradial notch be restricted to the condition wherein the nonarticular surface extends along the suture entirely across the distal end of the radial completely separating adjacent radial facets. Recognition of the inplenary and explenary radial facets should be useful in consistency of description, evolutionary studies, paleoecologic implications, and classification of the cladid crinoids.

Autologous osteoarticular transfer from the proximal tibiofibular joint to the scaphoid and lunate facets in the treatment of severe distal radial fractures: A report of two cases

Purpose: This study was conducted to determine the appropriateness of using the articular cartilaginous surfaces of the proximal tibiofibular joint to resurface damaged distal radial articular surfaces and to assess the clinical results in the first 2 patients. Method: Cadaveric specimens of the facets of the proximal tibiofibular joints and distal radius were sized and compared. Two patients underwent transfer of a fibular facet. Results: The surface area of each of the proximal tibiofibular facets were larger than either the scaphoid or lunate facets of the distal radius. The 2 patients had excellent clinical results with minimal donor morbidity. Conclusions: Use of the articular surfaces from the proximal tibiofibular joint to replace damaged distal radial facets is possible and can be accomplished with excellent results and minimal morbidity. (J Hand Surg 2003;28A:332-341. Copyright © 2003 by the American Society for Surgery of the Hand.)

DEVONIAN CLADID CRINOIDS: FAMILIES GLOSSOCRINIDAE GOLDRING, 1923, AND RUTKOWSKICRINIDAE NEW FAMILY

Abstract 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 stag...

Devonian cladid crinoids: Families Glossocrinidae Goldring, 1923, and Rutkowskicrinidae new family

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 includeRutkowskicrinusnew genus,Decorocrinusnew 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 ofRutkowskicrinus patriciaen. 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, containingGlossocrinus, Charientocrinus, Catactocrinus, andLiparocrinus, 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 includeRutkowskicrinus patriciaenew genus and species,Rutkowskicrinus collierinew genus and species,Nassoviocrinus costatus(Goldring, 1954) new combination,Nassoviocrinus schultzei(Haarmann, 1921) new combination,Nassoviocrinus?duluki(Kesling, 1969) new combination,Nassoviocrinus?ornatus(Goldring, 1954) new combination,Nassoviocrinus?chilmanaenew species,Decorocrinus arkonensis(Goldring, 1950) new combination,Decorocrinus cooperi(Goldring, 1926) new combination,Quantoxocrinus clarkei(Williams, 1882) new combination,Glossocrinus halli(Goldring, 1923) new combination, andCharientocrinus bellitubatus(Kesling, 1973) new combination.

Carabocrinid crinoids from the Ordovician of northern Iowa and southern Minnesota

Four species of carabocrinids from the Ordovician of northern Iowa and southern Minnesota are described, namelyCarabocrinus radiatusE. Billings,C. vancortlandtiE. Billings,C. magnificusSardeson from the Middle Ordovician Dunleith Formation andC. slocomiFoerste from the Upper Ordovician Maquoketa Formation.Carabocrinus radiatusandC. vancortlandtiare also known from the Middle Ordovician of Ontario and Quebec. In addition,C. magnificusandC. vancortlandtiare recorded from the Decorah of the Twin Cities area and the Curdsville Limestone of Kentucky, respectively. Biogeographically, the Middle Ordovician carabocrinids from Iowa and Minnesota are most similar to those from rocks of similar age in the northern Appalachians.Development of the cup and its component plates inC. slocomiis almost entirely isometric so that the its shape is largely constant regardless of size. This species exhibits ridge canals on the shoulders of the radial plates in the cup. The ridge canals probably served for respiration. As expected, the number of ridge canals and their length increase with positive allometry compared to the size and volume of the cup. Growth of the ridge canals restricts the width of the radial facets.

Evolutionary convergence and parallelism in crinoid calyx design

Eleven basic constructional designs are defined among the Crinoidea. Calyx designs are defined primarily by shape, geometry of plates at the base of the calyx, tegmen shape, fixed calyx plates, number of arms, and nature of radial facets. These calyx designs include the following: multiplated bowls, multiplated bicones, conical mosaics, urns, cylinders, cones, ellipsoids, hands, bowls, bilateral recumbents, and fists. Most crinoid subclasses and orders contain crinoids with several of these designs. This significant convergence and parallelism in calyx design indicates that the morphological evolution of crinoids has been substantially constrained by constructional and fabricational limitations.

Illemocrinus amphiatus, a new cladid inadunate crinoid from the Middle Ordovician of Ontario

A new cladid inadunate crinoid, Illemocrinus amphiatus n. gen., n. sp., is described from the Middle Ordovician Bobcaygeon Formation of Ontario. Illemocrinus, the oldest known member of the Thalamocrinidae, is characterized by an obconical cup containing two anal plates including quadrangular radianal, narrow radial facets, isotomously branching arms, and an erect anal tube composed of vertical rows of nodose plates. Illemocrinus probably evolved from Palaeocrinus, indicating a North American origin for the Thalamocrinidae.

Platycrinites contractus (Gilbertson) and a new Platycrinites from the Lower Carboniferous of northern England

The monobathrid camerate genus Platycrinites is one of the most diverse Upper Palaeozoic crinoid taxa. In the large Lower Carboniferous crinoid fauna of Salthill Quarry, Clitheroe, Lancashire, six species of Platycrinites are recognised, one of them new. The new taxon most closely resembles P. contractus (Gilbertson), which is adequately described for the first time herein. However, the new species, P. jameswrighti sp. nov., differs in having broad radial facets with symplexial articulation rather than small elliptical facets with a synarthrial ridge, in having a more infolded based circlet and in being generally larger than P. contractus .

Catillocrinids from the Permian of eastern Australia

Two new catillocrinid genera are described from the Permian of eastern Australia. Notiocatillocrinus gen. nov. is erected for two species N. oakiensis sp. nov. — the type — from late Sakmarian/early Artinskian sediments in northern New South Wales, and N. nerimberae (McKellar) from early Artinskian sediments in Queensland. Taucatillocrinus gen. nov. is erected for T. cephalonus sp. nov. — the type — from late Artinskian sediments in southern New South Wales. A second species T.? giganteus sp. nov. from the same locality as the type is tentatively assigned to the genus. The genera are readily distinguished from those from the Permian of the now comparatively proximal Timor though both exhibit similarities to Paracatillocrinus Wanner from this island. Both genera provide valuable information on the morphology of their radial armbearing facets and mode of radial-arm articulation. A life orientation is suggested for Taucatillocrinus. It is unlike that interpreted for the genus Paracatillocrinus. Notiocatilloc...

RHABDOCRINUS VATAGINI SP. NOV., A NEW SPECIES FROM THE LOWER CARBONIFEROUS DEPOSITS OF THE MOSCOW BASIN

A new diagnosis is proposed for the crinoid family Rhabdocrinidae with emphasis on the structure of the radial facets. In Rhabdocrinus vatagini Arendt, sp. nov., the plates were probably flexible along their sutures as indicated by the presence of fossae for ligaments or muscles along the connecting surfaces.--P. M. Kier.

Rhabdocrinus n.g. from the Scottish Carboniferous Limestone

When describing the Scottish species Poteriocrinus scotocarbonarius, doubts were expressed about the propriety of assigning it to Poteriocrinus (Wright, 1937, p. 402, 1939–40, p. 17). Before creating a new genus, however, it was considered desirable to make an examination of one of the chief figured specimens of the genotype species P. crassus Miller and to compare it with P. plicatus Austin. Up to the present it has not been possible to do this, and such an outcome seems unlikely for some time to come. In view of the great amount of work that has been done on this and allied genera in recent years, it is now reasonably certain that our Scottish forms are quite distinct from any English or American species or genera hitherto described. Hence the new genus Rhabdocrinus now proposed. The name Poteriocrinus is now discarded in favour of the original Poteriocrinites (Bassler, 1938, Moore and Laudon, 1943). The genotype species was described by Miller in 1821. The specimen illustrated by him as fig. 1 on the plate opposite p. 69 is intended to portray a complete cup apparently from the right posterior side. It has a few columnals attached. According to this figure the radials have horseshoe-shaped facets. The Austins state that this figure is a restoration, and they give an illustration of the same specimen from the same position (Austin, T. and T., 1843–7, pi. 8, fig. 3c, p. 74). Here also the radial facets are not well shown. There is accordingly still a slight doubt regarding these structures on this specimen. On Miller's plate, however, are several figures of detached radials and on the plate opposite p. 67 is a diagrammatic representation of the complete cup of P. crassus. All these figures show radials with horseshoe-shaped facets and a distinct articulating cross ridge, the facets themselves only occupying part of the upper surface of the radials. This type of structure is taken as typical of the genus Poteriocrinites. In the new genus now proposed the facets are quite different in shape and occupy nearly all the upper surfaces of the radials with no trace whatsoever of a cross ridge. The pattern of the surfaces in fact consists of a series of fine crenulations or striations which cross the facets in a transverse direction, i.e. from front to back. In addition, some facets are characterized by little pustules and prominences which are more commonly observed near the centre and towards the back or interior surface of the facets. These features constitute the chief distinguishing character of the new genus. As to the family to which Rhabdocrinus should be assigned, it clearly does not belong to the Poteriocrinitidae as now defined (Moore and Laudon, 1943, p. 54, fig. 5), and since it is impossible under prevailing conditions to trace any known family to which it can be referred, the matter is left open at present.

III.—Psalidocrinus: A new genus of Crinoidea from the Tithonian of Stramberg

The species Eugeniacrinites stramlergensis was described by me in 1912 (pp. 161, 167, pi. iii, fig. 2) on the evidence of a single specimen (A). Examination of a better specimen (B), subsequently acquired, and believed to be of the same species, has convinced me that, though the species appears to belong to the family Eugeniacrinidæ, Zittel, still it belongs to none of the known genera. This new genus, it is true, resembles Apsidocrinus in the union of its interradial processes, which, form a kind of vault above the patinal cavity (Jaekel, 1907, p. 304; Remeš, 1912, pp. 163, 168), but it differs from that genus in the form of the interradial processes, and especially in the size and shape of the radial facets.