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The Lower Carboniferous (Tournaisian) crinoids from Hook Head, County Wexford, Ireland
... Thus, the direction of migration cannot be determined with any certainty. The crinoid fauna from the West Angle Bay is age equivalent to the Ivorian-age crinoids from Hook Head, Ireland (Ausich and Sevastopulo, 2001). Crinoids associated with H. cymrus from the Black Rock Limestone at West Angle Bay include the camerates Rhodocrinites versimilis (Grenfell, 1876), Actinocrinites laevissimus Austin and Austin, 1843, Dialutocrinus tessellatus (Phillips, 1836) and Platycrinites sp.; the cladids Blothrocrinus longidactylus (Austin and Austin, 1847) and Holcocrinus smythi (Wright, 1934); and the flexible Taxocrinus hibernicus (Wright, 1934) (Ausich and Kammer, 2006). ...
A new species of cladid crinoid, Hylodecrinus cymrus, is described from the Pembroke Limestone Group (Mississippian, Tournaisian, Courceyan) of West Angle Bay in south Pembrokeshire, Wales. It has a medium bowl-shaped aboral cup, with strong ridges extending across the basals and radials forming pits at the plate corners. It is most similar to the late Tournaisian H. carinatus (Hall, 1861) of North America but differs in having less strongly cuneate brachials that are longer than wide with more subtle carinae on the aboral side. This specimen represents the first report of this genus from Europe, which most probably migrated from North America.
... However, most American species initially assigned to Graphiocrinus have subsequently been transferred to other genera as compiled by Webster ( , 1977 Webster ( , 1993 Webster ( , 2003) and Webster and Webster, 2014. All Permian species from West Timor assigned or transferred to Graphiocrinus by Wanner ( , 1924 Wanner ( , 1937) are not considered to belong to the genus or are questionably considered to belong as defined by de Koninck and Le Hon (1854), revised by Moore and Plummer (1940) or revised by Ausich and Sevastopulo (2001). This also applies to species from the southern Urals and Sicily named by Yakovlev (1927 Yakovlev ( , 1934 Yakovlev ( , 1938) which are not reviewed herein. ...
In a series of papers published between 1916 and 1949 Johannes Wanner assigned or reassigned more than 1700 crinoid specimens to 26 species or subspecies of Graphiocrinus. Nine of the 26 species were subsequently transfered to other cladid genera by Wanner or other authors. Study of the amalgamated Netherlands collections of the West Timor crinoids in Naturalis Biodiversity Center in Leiden, resulted in recognition that few of the West Timor Graphiocrinus species unquestionably belonged to the genus. Review of these species and subspecies resulted in reassignment of 12 species to other genera, whereas other species and individual specimens are considered indeterminate members of several families because they lack the arms preventing positive generic identifications. This study also resulted in significant revision of the Erisocrinoidea. New taxa introduced are: Graphiocrinoidea n. superfam., Rautscholdticrinus n. gen., and Ekmelocrinus n. gen. Reassigned taxa are: Rautscholdticrinus indicus (Wanner, 1916) n. comb.; Rautscholdticrinus weidnerii (Wanner, 1937) n. comb.; Graffhamicrinus? crassus (Wanner, 1924) n. comb.; Neocatacrinus? depressus (Wanner, 1916) n. comb.; Ekmelocrinus amplior (Wanner, 1924) n. comb.; Ekmelocrinus subamplior (Wanner, 1949) n. comb.; Ekmelocrinus ovoides (Wanner, 1949) n. comb.; Ekmelocrinus verbeeki (Wanner, 1916) n. comb.; Ekmelocrinus vermistriatus (Wanner, 1916) n. comb., nomen correctum; Permiocrinus pumilus (Wanner, 1916) n. comb.; Permiocrinus quinquelobus (Wanner, 1916) n. comb.; and Apographiocrinus? rugosus (Wanner, 1916) n. comb. © 2015 Elsevier B.V. and Nanjing Institute of Geology and Palaeontology, CAS.
... Inclusion of Eireocrinus is questioned. Ausich and Sevastopulo (2001) placed Eireocrinus in synonymy with Holcocrinus Kirk, 1945, which was questioned by because of the difference in cup shapes. ...
The small crinoidal patch reef in the Bird Spring Formation near the mouth of Battleship Wash, Clark County, Nevada, has yielded the largest Early Permian crinoid fauna known in North America. Earlier studies of the fauna were based on 535 specimens. Additional collecting has yielded another 239 specimens. These new specimens provide new information about some of the earlier described species and include three new genera and seven new species, bringing the total recognized in the Battleship Wash fauna to 37 genera and 62 species. Representatives of the camerates, disparids, primitive cladids (cyathocrinitids and dendrocrinids), advanced cladids (formerly poteriocriniids), flexibles, and articulates are recognized in the Battleship Wash fauna. Of particular significance among these new specimens is the presence of an actinocrinid. A specimen formerly identified from the fauna is here recognized as an articulate. This is the first report of an actinocrinid and an articulate from the Permian of North America. Based on the abundance of large specimens of cladids with 10 or more arms, the Battleship Wash fauna is interpreted to have lived in a nearshore high energy shelf environment, which agrees with the paleogeographic position previously recognized for the Bird Spring Formation. New taxa introduced are: Poteriocrinites permicus n. sp., Bridgerocrinidae, n. fam., Ekteinocrinus battleshipensis n. gen. and sp., Arroyocrius brachiatus n. sp., Plummericrinus jelli n. sp., Plummericrinus? bulbosus n. sp., Aesiocrinidae n. fam., Elassocrinus cyathus n. gen. and sp., Oklahomacrinus triangulus n. sp., and Pentaxocrinus quinarius n. gen. and comb.
... Thus, the direction of migration cannot be determined with any certainty. The crinoid fauna from the West Angle Bay is age equivalent to the Ivorian-age crinoids from Hook Head, Ireland (Ausich and Sevastopulo, 2001). Crinoids associated with H. cymrus from the Black Rock Limestone at West Angle Bay include the camerates Rhodocrinites versimilis (Grenfell, 1876), Actinocrinites laevissimus Austin and Austin, 1843, Dialutocrinus tessellatus (Phillips, 1836) and Platycrinites sp.; the cladids Blothrocrinus longidactylus (Austin and Austin, 1847) and Holcocrinus smythi (Wright, 1934); and the flexible Taxocrinus hibernicus (Wright, 1934) (Ausich and Kammer, 2006). ...
A new species of cladid crinoid, Hylodecrinus cymrus, is described from the Pembroke Limestone Group (Mississippian, Tournaisian, Courceyan) of West Angle Bay in south Pembrokeshire, Wales. It has a medium bowl-shaped aboral cup, with strong ridges extending across the basals and radials forming pits at the plate corners. It is most similar to the late Tournaisian H. carinatus (Hall, 1861) of North America but differs in having less strongly cuneate brachials that are longer than wide with more subtle carinae on the aboral side. This specimen represents the first report of this genus from Europe, which most probably migrated from North America.
The youngest species of Amphoracrinus , A. tenax new species, is described from the Muldraugh Member of the Borden Formation (early Viséan) of north-central Kentucky. With this new occurrence, both the oldest and youngest named species of Amphoracrinus are from North America. Numerous Tournaisian and Viséan crinoid faunas are documented in the United States, but only four are known to contain Amphoracrinus . Morphological analysis indicates that A. tenax is more closely aligned with species from China than with species from Western Europe or other species from North America, where Amphoracrinus was most diverse and abundant, which has implications for understanding paleogeographic dispersal. The holotype of A. tenax was partially disarticulated on the seafloor before burial, and final burial occurred early during disarticulation. The relative state of disarticulation from pinnules to columnals suggests that plates bound only with ligaments disarticulated as a function of surface area of ligaments binding an articulation.
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Well-preserved specimens, such as complete individuals, crowns and cups, are the common focus for crinoid systematic research. Yet the majority of specimens are disarticulated ossicles which are essentially ignored. The incompleteness of the fossil record is even more so when we ignore potential sources of data. A new species of crinoid comes from a monospecific assemblage from the Pennsylvanian (Upper Carboniferous) of western Ireland. All specimens are from a float block of the Clare Shale Formation (Bashkirian stage) at Fisherstreet Bay, Doolin, County Clare, western Ireland. Heloambocolumnus (col.) harperi gen. et sp. nov. has a pentagonocyclic, heteromorphic column; the small, central lumen is in a shallow, circular claustrum; the articulation is radial symplectial; the crenulae are slightly swollen and peg-like close to the circumference; nodals have rounded, unsculptured epifacets; nodal articular facets are sunken and in which narrow internodals are situated; and circlets of tubercles on epifacet surround priminternodals. These columnals are associated with robust, uniserial brachial ossicles. This crinoid is most likely a cladid.
The Actinocrinitidae were among the most abundant crinoids worldwide during the Lower Mississippian. Recent systematic revisions of the family allow a revised genus- and species-level understanding of these crinoids globally and a more precise means by which to understand the temporal and facies distribution of genera and species in this important Mississippian family. Two genera with a total of five species of Actinocrinitidae (and five additional forms left in open nomenclature) are recognized from the Fort Payne Formation, including Actinocrinites jugosus (Hall, 1859), Actinocrinites spp. indeterminate, Thinocrinus gibsoni (Miller and Gurley, 1893), Thinocrinus lowei (Hall, 1858), Thinocrinus probolos (Ausich and Kammer, 1991), Thinocrinus akanthos new species, Thinocrinus sp. aff. T . gibsoni , Thinocrinus spp. indeterminate, and two taxa recognized as only Actinocrinitidae genus and species indeterminate. Actinocrinites tripus Ehlers and Kesling, 1963 is recognized as a junior synonym of Thinocrinus gibsoni . Thinocrinus , rather than Actinocrinites as previously thought, is the dominant Fort Payne Formation actinocrinitid. Fort Payne Formation carbonate buildup facies (wackestone buildups and crinoidal packstone buildups) each have characteristic species of Thinocrinus . Actinocrinites is relatively rare in the Fort Payne Formation, but occurs preferentially in crinoidal packstone buildups.
The Amphoracrinidae Bather, 1899 is redefined, and all genera of this family are diagnosed with objective characters. Dilatocrinus Webster and Lane, 1987 and Pimlicocrinus Wright, 1943 are transferred into the Amphoracrinidae. Type specimens that define Displodocrinus Webster and Lane, 1987 and Dilatocrinus Webster and Lane, 1987 are clarified. The emphasis here is on genus definition, and comprehensive species-level systematics is not attempted. However, Amphoracrinus blairi Miller and Gurley, 1896a and Amphoracrinus jessieae Miller and Gurley, 1896b are designated nomina dubia; Sampsonocrinus sp. Webster and Lane, 1987 is reassigned to Amphoracrinus rupinus Webster and Lane, 1987; Amphoracrinus divergens var. multiramosus (Meek and Worthen, 1866) is reassigned to Dilatocrinus multiramosus (Meek and Worthen, 1866); and Sunwaptacrinus nevadensis Webster and Lane, 1987 is reassigned to Displodocrinus nevadensis (Webster and Lane, 1987).
A low-diversity crinoid fauna is described from the Fitchville Formation, Lower Mississippian (Late Devonian to Early Mississippian) of Utah County, Utah. Based on the crinoid fauna, composed of Nunnacrinus olsoni new species, Paracosmetocrinus lundi new species, and Platycrinites sp., this fauna is interpreted as being from the Kinderhookian, Upper Fitchville Formation. This occurrence of Nunnacrinus extends the geographic and facies range of this genus in western North America and the geographic range of Paracosmetocrinus within western North America.
John Samuel Miller's A Natural History of the Crinoidea or Lily-Shaped Animals... (1821), the first monograph of the fossil crinoids, included only three species from what we would now call the British Silurian. The first monographic study devoted to the British Silurian crinoids was by John Phillips (in Murchison's The Silurian System, 1839), who described 14 species (eleven new), all from the Wenlock Series of the area around Dudley. These were conservatively placed in five genera, Cyathocrinites Miller, Marsupiocrinites Phillips, Hypanthocrinites Phillips, Actinocrinites Miller and Dimerocrinites Phillips; the same species are now divided between eleven genera. Eight of these taxa are type species, but none is now classified as either Cyathocrinites or Actinocrinites. Hypanthocrinites is a junior synonym of Eucalyptocrinites Goldfuss. The illustrations in Phillips, drawn by J. de C. Sowerby, were much superior to Miller's plates, but lacked his innovative 'exploded' diagrams.
The diverse Katian (Late Ordovician) through Llandovery (Early Silurian) crinoid fauna from Anticosti Island is described. Previously, six described species were known; with one now a nomen dubium and two others placed in open nomenclature, herein. In contrast, Katian through Llandovery Anticosti crinoids are now recognized with 49 named species assigned to 39 genera, including 41 new species and 18 new genera. Including all taxa left in open nomenclature, crinoid species-level richness is more than 60. The Anticosti Island crinoid fauna is highly endemic with 46 percent of genera only known from Anticosti Island and only three species known from elsewhere. This undoubtedly results because the temporal and geographic interval represented on Anticosti Island is extremely poorly known from elsewhere, especially in shallow-water facies with shelly faunas. The Anticosti fauna is very significant for understanding the macroevolutionary transition from the early to the middle Paleozoic Crinoid Evolutionary Faunas, which was mediated, in part, by end-Ordovician mass extinctions. Late Katian crinoid faunas from Anticosti Island are similar in composition to contemporaneous faunas elsewhere. "Silurian aspect" faunal elements are common in Anticosti Hirnantian faunas. The Rhuddanian, immediately following the end-Ordovician extinctions, contains the least diverse crinoid fauna on Anticosti Island, and this earliest Silurian fauna still retains some "Ordovician aspect" faunal elements. By the Telychian, the fauna is characteristically Silurian in composition.
Crinoid diversity and abundance was higher during the Early Carboniferous (Mississippian) than at any other time. Due to the systematic focus on more complete specimens of crinoids, some areas, like the White Peak of Derbyshire and Staffordshire, UK, have erroneously been considered poor in fossil crinoids. Indeed, cups and crowns have only rarely been found in this area, but many limestones and cherts from the White Peak are rich in disarticulated crinoid remains. Screwstones (=fossiliferous cherts) collected in Bradford Dale, Derbyshire, yielded the disarticulated stem fragments, preserved as natural moulds, of seven crinoid morphotaxa, which is more than half of the known species richness of the whole White Peak. Considering that the material studied herein came from one locality, it is thus probable that the diversity of Mississippian crinoids in the White Peak is somewhat higher than previously recognized. This study shows that disarticulated stem fragments can be used as a proxy to test the crinoid diversity of an area, and that with further study of not only cups and crowns, some areas preserve a diversity of crinoids that is more than previously known.
New discoveries and systematic revisions since the 1978 publication of the crinoid volumes of the Treatise on Invertebrate Paleontology provide new information about Devonian cladid crinoid evolution, diversity, and first and last occurrences. Summarizing these previous studies resulted in numerous conclusions, including the following. The overall diversity of the Devonian cladids does not reflect the diversity acmes and extinction patterns of the individual superfamilies within the Cyathocrinida and Dendrocrinida. Cyathocrinoidea and Codiacrinoida genera were minor elements in the diversity of Devonian Cyathocrinida that were dominated by Gasterocomoidea (acme in the Eifelian) genera. The Gasterocomidae and Cupressocrinitidae are a clade restricted to the Devonian and Early Mississippian. Primitive Dendrocrinids were replaced in the Devonian by the Glossocrinoidea (referred to as Transitional Dendrocrinids); the Advanced Dendrocrinids and articulates first occurred in the Devonian. Morphologic and stratigraphic differences justify systematic differentiation between these groups. The last occurrences of cladid genera were greater in the Emsian and Givetian than they were in the Frasnian with the exception of the gasterocomids. Advanced cladids with plesiomorphic conical cups are thought to be derived from the Transitional Dendrocrinids, whereas the evolution of those with bowl-shaped cups is uncertain, but may be from the cyathocrinids. Time gaps in the ranges of carry-through genera and the sparse record in the Lochkovian and Pragian suggest stratigraphic intervals for future research to help resolve evolutionary and taxonomic questions in the cladids.
The diverse biota from the marine deposits of the type area of the Devonian System was monographed by the Reverend George Ferris Whidborne, MA, FGS (1846-1910) between 1889 and 1907. Most well-preserved specimens of crinoids are cladids or monobathrids from the Middle and Upper Devonian of south and north Devon, respectively. The camerate crinoids are dominated by the monobathrid Hexacrinites spp., known from many thecae and several nominal species from the Middle Devonian Torquay Limestone Formation; other monobathrids are moderately common in the Upper Devonian. The dicyclic diplobathrid camerates are less speciose and are commonly poorly preserved. Diplobathrids include Rhodocrinites? sp. A (poor crown) and Rhodocrinites? sp. B (columnals); Acanthocrinus sp. (spinose thecal plate); Gilbertsocrinus sp. A (columnals); non Rhipidocrinus crenatus (Goldfuss) (possibly a monobathrid crown); Thylacrinus? sp. (fragment of theca); and rhodocrinitid? sp. indet. This is in stark contrast to the 5 genera and 9 nominal species of diplobathrids known from the lower Silurian, and the 3 genera and 14 nominal species in the Mississippian of the British Isles, many of which are known from multiple, well-preserved specimens. The potential reasons for this disparity are many, but must include lack of effort by collectors over the past 100+ years, limited outcrop area, poor preservation due to tectonic deformation and, probably, a genuine rarity of diplobathrids in the British Isles during the Devonian.
Fossil crinoids are common in the Much Wenlock Limestone Formation of the type area in Shropshire, yet remain poorly known because of their fragmentary preservation. Calceocrinid disparids are recognized from Wenlock Edge for the first time on the basis of distinctive brachial ossicles. More proximal brachials have a broad, U-shaped adoral groove and an axial canal; distal ossicles have a narrower, V-shaped adoral groove and no axial canal. What remains surprising is that the most distinctive element of the calceocrinid endoskeleton, the fused basal circlet, remains unknown from Wenlock Edge.
A crinoid pluricolumnal displaying an irregular line of three pits that show a progressive increase in size was infested while the crinoid was alive; this is indicated by the swollen column and deformities of columnals. Such infestations are rare in the British Silurian. The pits may have been made by a single infesting organism which migrated up or down the column in response to the influence of gravity.
A small collection of well-preserved crinoid attachment structures from the Upper Devonian Pilton Formation of north Devon indicates the presence of two distinct species. Sostronocrinus mundus (Whidborne) lived attached to an unlithified sedimentary substrate by the vertical insertion of a robust, terminal rhizoidal holdfast abetted by robust, unbranched radices oriented laterally or curved distally. There was a strong differentiation of morphology between the radicular attachment and the more proximal column, which lacked radices. Eumorphocrinus porteri (Whidborne) attached to a similar substrate by an irregularly heteromorphic, tapering radicular runner bearing branched radices that promoted permanent attachment close to the sediment surface. These radices were probably developed on at least part of the more proximal column. The highest columnals of the dististele do not bear radices and, therefore, are not nodals. The dististele was previously unknown in both of these species.
A glut of fossil crinoids does not lead to a succession being recognised as rich in crinoids. Crinoid palaeontology relies on cups, crowns and complete specimens, not fragments. The Carboniferous Limestone of the White Peak is rich in crinoid fragments, but depauperate in named crinoids. Something needs to be done.
The biodiversity and biogeography of 217 genera of Mississippian crinoids from North America and the British Isles shed light on the macroevolutionary turnover between the Middle Palaeozoic and Late Palaeozoic Crinoid Evolutionary Faunas. This turnover resulted from steady differential extinction among clades during the middle Mississippian after crinoids reached their Phanerozoic peak of generic richness during the early Mississippian. This peak richness was primarily a function of Mississippian originations rather than Devonian–holdover taxa. North America had 100 per cent higher generic richness than the British Isles, but rarefaction analysis adjusts the difference to only 37 per cent higher. Rarefaction demonstrated that North America had increased biodiversity, compared to the British Isles, almost entirely among monobathrid camerates, disparids and primitive cladids. In contrast, diplobathrid camerates, advanced cladids and flexibles had the same generic biodiversity between regions, when compared using rarefaction. The early Mississippian radiation resulted from two primary causes: (1) the expansion of Tournaisian carbonate ramps following the Frasnian mass extinction of reef faunas and (2) the predatory release in the Tournaisian following the end‐Famennian Hangenberg extinction of durophagous fishes. A majority of crinoid genera from the British Isles are cosmopolitan. When combined with rarefaction analysis and evidence for more first occurrences in North America, this suggests higher origination rates in North America, especially when carbonate ramps were widespread. With the gradual reduction in the area of carbonate ramps from the early to late Mississippian, in conjunction with the radiation of new durophagous fishes, camerate crinoids in particular experienced continuous background extinction, without replacement, beginning during the earliest Viséan (late Osagean). By middle Viséan time (late Meramecian) advanced cladids were dominant in all settings. This resulted in the transition from the Middle Palaeozoic to the Late Palaeozoic Crinoid Macroevolutionary Fauna.
Crinoids were first reported from the Cuyahoga Formation in northeastern Ohio by James Hall in 1863. However, these crinoids have not been re-examined in detail since the late nineteenth century. With the restudy of classical and more recent collections, ten (nine camerate and one disparid) species-level taxa are recognized from the late Kinderhookian Meadville Shale Member, Cuyahoga Formation, including the camerates Amphoracrinus viminalis (Hall, 1863); Aorocrinus helice Hall, 1863; Aorocrinus meyeri n. sp.; Aryballocrinus martini n. sp.; Cusacrinus daphne (Hall, 1863); Platycrinites s.1. contritus (Hall, 1863); Platycrinites s.1. graphicus (Hall, 1863); Platycrinites s.1. lodensis (Hall and Whitfield, 1875); and Platycrinites s.1. burkei n. sp. In addition, Halysiocrinus sp. is the first disparid reported from this fauna. Platycrinites s.1. bedfordensis (Hall and Whitfield, 1875) is designated a nomen dubium. Growth is evaluated for Aorocrinus helice and Cusacrinus daphne, which had contrasting development. The growth of the Aorocrinus helice calyx was largely not allometric but that of the primaxil plate was, suggesting the arms may have grown allometrically. In contrast, much of the calyx of Cusacrinus daphne displayed allometric growth.
The Nunn Member (early Osagean) of the Lake Valley Formation of New Mexico is known for its abundance and diversity of crinoids. Although crinoids were first reported in the late 1800s, no comprehensive study of the crinoids has been conducted and a complete list of the crinoid taxa does not exist. All subclasses of crinoids occur in the Lake Valley, but the camerates are by far the dominant group. Study of the Macurda collection from the University of Michigan, the Laudon collection from the University of New Mexico, and new collections provided more than 7000 specimens, 4,500 of which were identifiable camerates. Sixty-one species of camerates are recognized in the Nunn Member, including five new species: Blairocrinus macurdai, Iotacrinus novamexicanus, Agaricocrinus alamogordoensis, Uperocrinus kuesi, and Collicrinus laudoni. This camerate fauna is very similar to that of the lower Burlington Limestone of the Mississippi Valley. An update of the crinoid taxa in the Lake Valley Formation allows for a better understanding of the temporal and geographic relationships of crinoid faunas across North American during the Early Mississippian when camerates were at their global diversity maximum. The majority of the camerates come from the western New Mexico outcrops where the Nunn Member is thicker and the marine shelf was shallower, but several also occur in association with the deep-water Waulsortian mounds.
A diverse Tournaisian (Carboniferous, Mississippian) brachiopod fauna has been recorded within the stratotype of the tempestite-dominated Hook Head Formation at Hook Head, County Wexford (south-east Ireland). The Hook Head Formation (335 m thick), which mainly consists of interbedded limestones of tempestite origin and shales, deposited on a shelf–ramp and yielded a rich invertebrate fauna (crinoids, bryozoans, corals, etc.). Thirty-three brachiopod species, of which one is new (Rugosochonetes sleemani), assigned to 29 genera, have been recognized. The brachiopod fauna is dominated by productides and spire-bearers (athyridides, spiriferides, and spiriferinides) and shares strong similarities with those reported in Wales and southern Belgium (Namur–Dinant Basin), which derived from the same palaeogeographical context.
Platycrinitid camerate crinoids, with distinctive elliptical columnals and large dorsal cups are a characteristic feature of the Lower Carboniferous of the British Isles. Two new occurrences are reported here. Disarticulated basal circlets and low radials from the Brigantian of Coverdale, Yorkshire, have been reconstructed as a dorsal cup, identified as Platycrinites sp. Although both smooth and tuberculated plates are present, intermediate morphologies suggest that these represent one variable species. It is rare that pelmatozoan thecae or cups can be reconstructed from disarticulated elements. Platycrinites sp. is believed to be the first such reconstruction to be published from the Palaeozoic of the British Isles. The second new occurrence comprises cups of a platycrinitid species from Lathkill Dale in the Peak District, Derbyshire, preserved in a stile in a dry stone wall. This occurrence is notable as being one of the few reports of identifiable crinoid remains from the Lower Carboniferous of the Peak District since the 19th century.
Sixty genera of Mississippian crinoids, comprising 191 species, are evaluated from 83 localities in England and Wales, based on modern revisions from the literature, study of museum collections and new field work. These genera occurred through ten time units in the Mississippian (Tournaisian-Serpukhovian). Among the 191 species, 161 are considered valid with 28 requiring new combinations of genus and species names. Twelve species are considered nomina dubia, one species is considered a nomen nudum, three species cannot be assigned with certainty to a genus, and 14 can only be assigned at the generic level. Hastarian (Times 1 and 2) faunas have a very low generic richness with only one genus known. Ivorian (Time 3) faunas have a substantially higher generic richness with 21 genera known. Chadian faunas have the highest generic richness with 28 genera from the lower Chadian (Time 4) and 19 genera from the upper Chadian (Time 5). Post-Chadian faunas include those from the Arundian (Time 6), Holkerian (Time 7), Asbian (Time 8), Brigantian (Time 9) and Pendleian (Time 10); all have low generic richness with 0, 4,7, 13 and 7 genera known, respectively. The dominant Mississippian crinoid faunas are on Ivorian carbonate ramps, Chadian Waulsortian and Waulsortian-related facies, and in the Pendleian marine beds that supported Woodocrinus. In comparable facies, the composition of faunas is similar in England and Wales and North America, although generic richness is commonly lower in England and Wales. The overall crinoid fauna has much lower generic richness in England and Wales than in North America because the stratigraphical record of England and Wales preserves a much lower diversity of crinoid-bearing facies. The critical Arundian-Holkerian interval for Palaeozoic crinoid history is poorly represented in England and Wales.
The sea defence/coastal protection works at Barton-on-Sea, Hampshire, include blocks of Carboniferous Limestone (Clifton Down Limestone Formation; Dinantian, Holkerian) from the Foster Yeoman ‘Torr Works’ Quarry at Merehead, East Cranmore, Shepton Mallet, Somerset. A rich fauna of echinoderms, corals, bryozoans, trilobites, brachiopods and gastropods is present in these blocks. The echinoderms include plates of the tests of the echinoids Palaechinus sp., Archaeocidaris sp. and an indeterminate echinoid; calyces of the crinoids platycrinitid sp., Actinocrinites sp. aff. A. rotundatus Wright, monobathrid sp. indet., camerate sp. indet. and Taxocrinus sp.; and numerous ossicles, including Cyclocyclicus (col.) sp. and Pentagonocyclicus (col.) spp. Camerates were important members of early Carboniferous crinoid faunas, although the absence of cladids is notable.
Examination of any fossils contained within coastal protection blocks is an important source of information when the place of origin of the blocks is known but is unavailable for study purposes.
The Batocrinidae was a component of the North America Early Mississippian crinoid fauna and a significant contributor to the global biodiversity spike referred to as the “Age of Crinoids.” All batocrinids are North American, and all but one species are confined to the Tournaisian and Visean. In this contribution, genera are objectively defined on discrete characters, and the generic assignment of all valid species is re-evaluated. A phylogenetic hypothesis is presented for relationships within the Batocrinidae based on parsimony-based analyses and known stratigraphic ranges.
Fifteen basic batocrinid architectural designs are recognized as genera, and four new genera are described: Glannearycrinus n. gen., Gongylocrinus n. gen, Magnuscrinus n. gen., and Simatocrinus n. gen. Batocrinus was a catch-all genus for any Mississippian camerate with tetragonal first primibrachials and an anal tube; thus, many late 19 th century species are in need of a modern generic assignment. In this contribution, 61 percent of the 166 currently valid batocrinid species are reassigned to different genera. In addition, Sunwaptacrinus is transferred to the Batocrinidae, six species are transferred out of the Batocrinidae, and five species are designated as nomina dubia.
Platycrinites is traditionally one of the more recognizable crinoids, a camerate crinoid with very few if any fixed brachials or interradials and a helically twisted column. Accordingly, many taxa have been assigned to this genus. With a better understanding of the Platycrinitidae, these characters actually unite the family Platycrinitidae rather than the genus. Further, use of different genus-diagnostic characters in Western Europe versus North America has resulted in a confused systematics for this important late Paleozoic family. Here, we objectively define genera within the Platycrinitidae and assign all species to either newly defined or newly named genera. A phylogenetic hypothesis, incorporating both parsimony-based character analysis and stratigraphic ranges, of the genera within the Platycrinitidae is presented. With consideration of the type species, Platycrinites laevis Miller, 1821, Platycrinites sensu stricto is distinguished from Platycrinites sensu lato, which is used for species that cannot be assigned with confidence to any objectively defined genus. New genera are Artaocrinus n. gen., Collicrinus n. en., Elegantocrinus n. gen., and Laticrinus n. gen.; and Exsulacrinus Bowsher and Strimple, 1986 is designated a junior synonym of Platycrinites s.s. Collicrinus Shumardi n. gen. and sp., Laticrinus oweni n. gen. and sp., and Laticrinus wachsmuthi n. gen. and sp. are described; and Platycrinites formosus approximatus (Miller and Gurley, 1896a) is designated a junior synonym of Platycrinites formosus (Miller and Gurley, 1895a), which is reassigned here to Collicrinus n. gen. Platycrinites s.s. now includes 14 species and species-level taxa, and 76 species are assigned to Platycrinites s.l. Ten species are designated nomina dubia, as are taxa based solely on columnals or pluricolumnals. Two species are designated nomina nuda, and two are transferred to genera outside of the Platycrinitidae. In addition, twenty-seven species and four open-nomenclature taxa are each reassigned to a different genus.
The Amphoracrinidae Bather, 1899 is redefined, and all genera of (his family are diagnosed with objective characters. Dilatocrinus Webster and Lane. 1997 and Pimlicocrinus Wright, 1943 are transferred into the Amphoracrinidae. Type specimens that define Displodocrinus Webster and Lane, 1987 and Dilatocrinus Webster and Lane. 1987 are clarified. The emphasis here is oil genus definition, and comprehensive,species-level systematics is not attempted. However, Amphoracrinus blairi Miller and Gurley, 1896a and Amphoracrinus jessieae Miller and Gurley, 1896b are designated nomina dubia; Sampsonocrinus sp. Webster and Lane, 1987 is reassigned to Amphoracrinus rupinus Webster and Lane, 1987; Amphoracrinus divergens var. multiramosus (Meek and Worthen. 1866) is reassigned to Dilatocrinus multiramosus (Meek and Worthen, 1866); and Sunwaptacrinus nevadensis Webster and Lane, 1987 is reassigned to Displodocrinus nevadensis (Webster and Lane, 1987).
New Devonian (Frasnian and Famennian) crinoids are described from central and eastern Iran and a new Mississippian (late Tournaisian) echinoderm fauna is described from the south flank of the Alborz Mountains of northern Iran. Both the Devonian and Mississippian echinoderms were living in a carbonate, shelf basin on the northern flank of Gondwana at approximately 30 degrees south latitude. The geographic ranges of Hexacrinites and Eutaxocrinus are extended onto the northern margin of Gondwana and add to the sparsely known Famennian crinoids. The Mississippian fauna is dominated numerically and in diversity by cladids, unlike most late Tournaisian faunas that are dominated by camerates in numbers, if not diversity. The late Tournaisian fauna is most similar to a coeval fauna from southern Iran, both of which have a noted lack of actinocrinitids and rare platycrinitids. It also shows similarity with Tournaisian faunas of western North America with four common genera. New species introduced are: Hexacrinites persiaensis, Eutaxocrinus risehensis, Dichocrinus damghanensis, Amabilicrinus stellatus, Bridg-erocrinus alborzensis, Bridgerocrinus semnanensis, Paracosinetocrinus mobarakensis, Decadocrinus clypeus, and Palaechinus iranensis.
A well-preserved calyx of the monobathrid camerate crinoid Amphoracrinus gilbertsoni (Phillips) from the Lower Carboniferous (Chadian, Viséan) of Salthill Quarry, Clitheroe, Lancashire, is preserved in close association with a solitary rugose coral. Evidence for the coral being an epizoozoan on the crinoid includes its perpendicular orientation to the calyx, its position at the base of a free arm (B ray) in the AB interray, breakage of the crinoid plates around the coral (calyx ligamentation had not rotted post-mortem), and a growth deformity in the AB interray. The position of the coral indicates that, in life, it was elevated above the sea floor and directed into the prevalent water current by the crinoid. Its position, adjacent to a free arm and growth deformity of the AB interray suggest it was also a parasite on the adoral groove of the crinoid arm.
The National Natuurhistorisch Museum, Leiden (NNM), and the Teyler Museum, Haarlem, are contrasting museums separated more by their building style and history than the geographical distance. The NNM includes a collection of over two million minerals, rocks and fossils housed in a new, purpose-built exhibition building and associated 20-storey collections tower. Collections are diverse, but include significant holdings from The Netherlands and former Dutch colonies. Highlights of the collection and research facilities that were demonstrated included The Netherlands Gemmological Laboratory, palaeobotany collections, brachiopods, Cenozoic benthic molluscs, mammals, benthic foraminifera and echinoderms. In contrast, the Teyler Museum building has evolved since the eighteenth century, and the public displays of rocks and fossils still retain much of their original form. Certain specimens of extreme historical importance are on display, such as Homo diluvi testis, early mosasaur finds and an Archaeopteryx.
The first monograph of the British Silurian crinoids was published as early as 1839 and identified 14 species; over 120 are now known. The most productive horizon for both diversity of species and numbers of well‐preserved specimens is the Much Wenlock Limestone Formation at Dudley (Lower Silurian, Wenlock), a site of international significance. Other localities have produced fewer, but different species. Herein, we introduce the most important crinoid localities in the Llandovery to Ludlow of the British Isles, and figure some of the many beautiful and significant specimens that they have produced.
Gilbertsocrinus is a common Middle Devonian to Lower Mississippian crinoid from Europe, North America, and China. This crinoid has several very unusual features, such as tegmen appendages, minute arms, a very flexible column, and an unusual holdfast. It is demonstrated that a bulbous holdfast does not exist in Gilbertsocrinus, as previously interpreted. Gilbertsocrinus is an unusual crinoid; however, it has a distal coil rather than a tuberous holdfast.Gilbertsocrinus est un crinoïde répandu du Dévonien moyen au Mississippien inférieur d'Europe, d'Amérique du Nord et de Chine. Ce crinoïde présente plusieurs caractéristiques inhabituelles telles que des appendices du tegmen, de minuscules bras, une colonne très flexible et un crampon inhabituel. Il est démontré que, contrairement aux interprétations antérieures, un crampon bulbeux n'est pas présent chez Gilbertsocrinus. Si le crampon de Gilbertsocrinus est effectivement inhabituel, il s'agit d'une spirale distale plutôt que d'un crampon tubéreux.
During the Mississippian (Tournaisian), numerous crinoid genera of the subclass Camerata evolved exaggerated anal tubes, cylindrical extensions of the tegmen with the anus at the distal end. Additionally, camerates exhibit higher frequency of platyceratid gastropod infestation than any other crinoid clade leading some researchers to speculate that anal tubes evolved in response to platyceratid parasitism. To test the infestation avoidance role of anal tubes, platyceratid distribution was analyzed among 636 tubed and 675 tubeless crinoids from Mississippian strata in North America. Results demonstrate significantly higher infestation frequency in tubeless crinoids. Rather than attach to the anal vent, as is typical for platyceratids, the gastropods that infested tubed crinoids are always found at the tube base and acquired nutrients from their hosts via drilling. It is likely that infesting tubeless crinoids was a more cost effective trophic strategy than drilling tubed crinoids.
Analysis of anal plates of type species of most cladid crinoid genera (excluding codiacrinid and some gasterocomacids) recognizes four catagories of anal plating conditions designated: Parioplax, Menoplax, Mesoplax and Opioplax. These four plating conditions are subdivided into 23 anal subconditions. These various anal conditions reflect recognized general evolutionary trends within all orders of the cladids. This corrects, describes more precisely, and replaces the widely used terms ‘primitive’ and ‘advanced’ to describe anal conditions, either of which can occur in older or younger cladid crinoids. The morphological terms primanal, secundanal and tertanal should be used in place of the terms radianal, anal X and right tube plate, respectively, in most cladid and flexible crinoids. Anal X should be used only for those genera for which it has been demonstrated that the primanal was resorbed or migrated out of the cup. In most genera having cups with a single anal this rectifies the misnomer of referring to the single anal as anal X when it is actually the primanal that has migrated into the position previously occupied by the secundanal, pushing the secundanal out of the cup. The origin of cladid anals is not considered homologous to camerate anals, but the use of similar terms for descriptive purposes is given precedence over use of a misnomer. Recognition of the anal-plate positions and clarification of anal-plate homologies are important in cladid phylogenetic analysis. Results of this study strongly support punctuated and mosaic evolution within the anal-plate series of cladid crinoids. Application of the new terminology further implies that the classification of some polyphyletic genera and families may be the result of convergence, wherein greater emphasis has been placed on the anal condition for genus or family assignment than has been placed on other equally significant morphological features.
A total of 47 genera, in 80 species, of Mississippian, or Lower Carboniferous, crinoids are evaluated from 61 localities in Scotland based on a modern update of the literature, study of museum collections, and new field work. Among the 80 species, 76 are considered valid, with eight requiring new combinations of genus and species names. In addition, one species is considered a nomen dubium, and three can only be assigned at the generic level. Asbian faunas have a moderate generic richness of 13. Brigantian faunas have the highest generic richness at 40. Arnsbergian faunas have the lowest generic richness at three. There are no Mississippian crinoid faunas in Scotland older than Asbian. The dominant Brigantian crinoid faunas occur in limestones and shales in the shallow shelf marine intervals of Yoredale-style cyclothems. The Asbian faunas occur in shallower, nearshore mudstones and limestones of Yoredale-style cyclothems. The late Viséan (Brigantian) fauna is more similar in overall taxonomic composition to the global record for the Serpukhovian rather than the Viséan. This reflects the establishment of the Late Palaeozoic Crinoid Macroevolutionary Fauna, dominated by advanced cladid crinoids, by the end of the Viséan in Scotland.
The modern study of fossil crinoids began with J. S. Miller who, in 1821, described specimens from southern England, nearby Wales and other regions, and named several common Early Carboniferous genera. Later, in 1950–60, James Wright monographed all known Early Carboniferous crinoids from the British Isles. In spite of such previous scrutiny, we recognize here two new genera among species already described: Glamorganocrinus gen. nov. (type species: Ophiurocrinus gowerensis Wright, 1960) from South Wales and Mendipocrinus gen. nov. (type species: Poteriocrinus latifrons Austin and Austin, 1847) from southern England. These new genera increase the number of advanced cladid genera in the Ivorian Substage of the Tournaisian in western Europe to 18, and the total number of crinoid genera to 36. A review of species assigned to Mespilocrinus has led to the recognition of M. granulifer De Koninck and LeHon, 1854 as a nomen dubium. A new species of Mespilocrinus, M. wrighti sp. nov., is described from the Ivorian of South Wales; this is the most highly derived species of the genus, as based on a phylogenetic analysis including ten species and 13 characters, with Pycnosaccus as the outgroup. A single, well-ordered tree resulted from this analysis. Interpretation of this tree suggests that the centre of evolution for Mespilocrinus was North America, where three species appeared during the Kinderhookian (early Tournaisian), rapidly achieving morphological disparity within the genus. This radiation event was part of the overall explosive radiation of crinoids following the Late Devonian mass extinction event when crinoid diversity was at a global minimum during the Frasnian. Recovery began during the Famennian, followed by an explosive radiation in the Tournaisian.
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