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1
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Comment and reply on "Palaeoenvironmental control on distribution of crinoids in the Bathonian (Middle Jurassic) of England and France" by Aaron W. Hunter and Charlie J. Underwood

100%
Hunter A. W., Underwood C. J.
Acta Palaeontologica Polonica
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2010
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tom 55
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nr 1
2
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Comment on "Palaeoenvironmental control on distribution of crinoids in the Bathonian (Middle Jurassic) of England and France" by Aaron W. Hunter and Charlie J. Underwood

100%
Salamon M. A., Gorzelak P., Zaton M.
Acta Palaeontologica Polonica
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2010
|
tom 55
|
nr 1
3
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Multi-snail infestation of Devonian crinoids and the nature of platyceratid-crinoid interactions

100%
Baumiller T. K.
Acta Palaeontologica Polonica
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2002
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tom 47
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nr 1
The well−known association of platyceratid snails and crinoids typically involves a single snail positioned on the tegmen of the crinoid host; this has led to the inference of coprophagy. Two specimens of the camerate crinoid Arthroacantha from the Middle Devonian Silica Formation of Ohio, USA, exhibit numerous snails on their tegmens. On one of these, 6 platyceratid juveniles of approximately equal size are found on the tegmen. On the second crinoid, the largest of 7 infesting platyceratids occupies the typical position over the anal vent while others are either superposed (tiered) upon it or are positioned elsewhere on the tegmen. These specimens illustrate that platyceratids (1) settled on crinoids as spat, (2) were not strictly coprophagous during life yet (3) benefited from a position over the anal vent.
4
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Epibionts on upper Eifelian crinoid columnals from the Holy Cross Mountains, Poland

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Gluchowski E.
Acta Palaeontologica Polonica
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2005
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tom 50
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nr 2
Most of 378 upper Eifelian crinoid columnals collected from the lower part of Skały Beds in the Holy Cross Mountains display traces of borings produced by endobionts, but only approximately 20% of them show traces of epibionts. These infested crinoids are represented by 5 stem−based species: Tantalocrinus scutellus, Schyschcatocrinus creber, Gilbertsocrinus vetulus, Pentagonostipes petaloides, and Cycloocetocrinussp. They were fouled by 19 species of suspension−feeding epibionts, including saccamminid foraminiferans, rugose and tabulate corals, cyrtinitid and productid brachiopods, “ctenostome bryozoans”, “cyclostome bryozoans”, cystoporate bryozoans, and rhabdomesid? bryozoans, crinoids, and organisms of uncertain affinities. The majority of these epibionts were opportunistic commensals colonizing living crinoids, and only some utilized dead crinoids as hard substrate for attachment. At least some of these epibionts seem to have settled selectively on particular crinoid host species.
5
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Functional anatomy and mode of life of the latest Jurassic crinoid Saccocoma

100%
Brodacki M.
Acta Palaeontologica Polonica
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2006
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tom 51
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nr 2
Loose elements of the roveacrinid Saccocoma from the Tithonian red Rogoża Coquina, Rogoźnik, Pieniny Klippen Belt, Poland, are used to test the contradictory opinions on the mode of life of Saccocoma. The investigated elements belong to three morphological groups, which represent at least two separate species: S. tenella, S. vernioryi, and a third form, whose brachials resemble those of S. vernioryi but are equipped with wings of different shape. The geometry of brachials’ articular surfaces reveals that the arms of Saccocoma were relatively inflexible in their proximal part and left the cup at an angle of no more than 45, then spread gradually to the sides. There is no evidence that the wings were permanently oriented in either horizontal or vertical position, as proposed by two different benthic life−style hypotheses. The first secundibrachial was probably more similar to the first primibrachial than to the third secundibrachial, in contrast to the traditional assumption. The winged parts of the arms were too close to the cup and presumably too stiff to propel the animal in the water efficiently. Swimming was probably achieved by movements of the distal, finely branched parts of the arms. The nonhorizontal attitude of the winged parts of the arms is also not entirely consistent with the assumption that they functioned as a parachute. Moreover, the wings added some weight and thus increased the energy costs associated with swimming. The hydrodynamic benefits balancing these extra costs are not entirely clear, but it seems probable that the wings reduced the sinking rate of the animal not by increasing the pressure drag, as suggested by the parachute−analogy, but by increasing the surface drag (friction drag), which also harmonize with the presence of spines, reticulate sculpture and conspicuous vacuolar ornamentation in some species of Saccocoma.
6
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Crinoids from the Famennian of the Holy Cross Mountains, Poland

100%
Gluchowski E.
Acta Palaeontologica Polonica
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2002
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tom 47
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nr 2
Disarticulated crinoid columnals and pluricolumnals from the Famennian of the Holy Cross area were analysed. Sixteen crinoid taxa were distinguished, only one of which is based on stems attributed to a calyx−based genus, and the others are classified within artificial supraspecific units. Two of these are new: Schyschcatocrinus levis sp. nov. and Cosmocrinus polonicussp. nov. The described crinoid fauna shows distinct extinction−recovery temporal pattern: the Frasnian–Famennian crisis affected 50% of stem−based families and 70% of late Frasnian stem−based genera. The succession of crinoid faunas represented by three faunal intervals has been identified and correlated to standard conodont zones: FIa, Palmatolepis triangularis Zone (relic “Frasnian” crinoid assemblage Schyschcatocrinus delicatus–Calleocrinus kielcensis), FIb, Pa. crepida to Pa. marginifera zones (crinoid assemblage Calleocrinus kielcensis–Schyschcatocrinus levis) and FIc, Pa. trachytera to S. praesulcata zones (crinoid assemblage Cosmocrinus polonicus–Acbastaucrinus affectatus). The succession was controlled mostly by eustatic factors.
7
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Revision of the flexible crinoid genus Ammonicrinus and a new hypothesis on its life mode

80%
Bohaty J.
Acta Palaeontologica Polonica
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2011
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tom 56
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nr 3
The lecanocrinid Ammonicrinus(Flexibilia) is newly interpreted based on new material from the Middle Devonian of the Rhenish Massif (Eifel and Bergisches Land, Germany). The species have echinoid−like tubercles on the attachment and on the column, which bear articulated spines. The intraspecific variability of the column is discussed for three facies−controlled morphotypes, herein classified as standard “exposed−” or “encased roller−type” and the rare “settler−type”. New specimens have floating transitions between different plate sculpturing and between those individuals with none or one to several columnals with herein termed “lateral columnal enclosure extensions” on the proximal−most, barrel−like dististele and the following mesistele, which is solely distinguished by these extensions. Based on this interpretation, Ammonicrinus kongieli is evaluated as a subjective junior synonym of Ammonicrinus sulcatus. The latter species was first recognised from the Eifel (Germany). “Ammonicrinus wachtbergensis”, from the upper Eifelian of the Eifel, is declared a subjective junior synonym of Ammonicrinus doliiformis. The first nearly complete specimen of Ammonicrinus kerdreoletensis is described from the lower Eifelian of Vireux−Molhain (southern Ardennes, France). Two new species are described: Ammonicrinus jankei sp. nov. and Ammonicrinus leunisseni sp. nov. A functional morphologic trend in perfecting the crown encasement by continuous modification of the lateral columnal enclosure extensions of the mesistele from the Eifelian to the Givetian, indicates a vagile benthic “predator”−driven evolution of ammonicrinids in the Eifel area. Several ammonicrinid species are herein defined as spined soft−bottom dwellers, feeding in low−intensity current water, possibly through a self−produced water flow. The first known postmortem encrusting epizoans on ammonicrinid endoskeletons are reported.
8
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Crinoids from the Silurian of Western Estonia

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Ausich W. I., Wilson M. A., Vinn O.
Acta Palaeontologica Polonica
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2012
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tom 57
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nr 3
The Silurian crinoids of Estonia are re−evaluated based on new collections and museum holdings. Nineteen species−level crinoid taxa are now recognized. All crinoid names applied to Estonian Silurian crinoids during the middle 19th century are disregarded. Especially significant is the fauna reported herein from the Pridoli because coeval crinoids are very poorly known from the Baltic region and elsewhere. One new genus and four new species are described from Estonia, namely Calceocrinus balticensis sp. nov., Desmidocrinus laevigatus sp. nov., Eucalyptocrinites tumidus sp. nov., and Saaremaacrinus estoniensis gen. et sp. nov.
9
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Palaeoenvironmental control on distribution of crinoids in the Bathonian [Middle Jurassic] of England and France

80%
Hunter A. W., Underwood C. J.
Acta Palaeontologica Polonica
|
2009
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tom 54
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nr 1
77-98
Bulk sampling of a number of different marine and marginal marine lithofacies in the British Bathonian has allowed us to assess the palaeoenvironmental distribution of crinoids for the first time. Although remains are largely fragmentary, many species have been identified by comparison with articulated specimens from elsewhere, whilst the large and unbiased sample sizes allowed assessment of relative proportions of different taxa. Results indicate that distribution of crinoids well corresponds to particular facies. Ossicles of Chariocrinus and Balanocrinus dominate in deeper−water and lower−energy facies, with the former extending further into shallower−water facies than the latter. Isocrinus dominates in shallower water carbonate facies, accompanied by rarer comatulids, and was also present in the more marine parts of lagoons. Pentacrinitesremains are abundant in very high−energy oolite shoal lithofacies. The presence of millericrinids within one, partly allochthonous lithofacies suggests the presence of an otherwise unknown hard substrate from which they have been transported. These results are compared to crinoid assemblages from other Mesozoic localities, and it is evident that the same morphological adaptations are present within crinoids from similar lithofacies throughout the Jurassic and Early Cretaceous.
10
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Genus Ammonicrinus (Crinoidea) from the Middle Devonian of the Holy Cross Mts (Poland)

80%
Piotrowski A.
Acta Palaeontologica Polonica
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1977
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tom 22
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nr 2
Crinoid genus Ammonicrinus is represented by two species, A. sulcatus Kongiel and A. kongieli sp.n., in the Grzegorzowice - Skały and Świętomarz - Śniadka profiles of the Middle Devonian in the Holy Cross Mts. The presence of barrel-like columnals of a limited mobility in distal part of stems and the development of wide tuberculated external cover indicate that both species represent sessile benthos. In A. sulcatus stem was connected with crown through modified columnalium. The crown was equipped with short arms which could take food in a space limited to the interior of coiled part of the stem. The food was supplied by current parallel to the bottom. The structure of crown and stem suggests that all Ammonicrinus species represent the same evolutionary stage.
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