A new scleritomous metazoan from the Late Ordovician Georgian Bay Formation, southern Ontario

1998 ◽  
Vol 35 (7) ◽  
pp. 827-831 ◽  
Author(s):  
David M Rudkin
Keyword(s):  
New Genus ◽  
Late Ordovician ◽  
New Genus And Species ◽  
Southern Ontario ◽  
Georgian Bay ◽  
Early Ordovician ◽  
Primary Composition ◽  
Level Group

A new genus and species of articulated scleritomous metazoan, Curviconophorus andersoni, is described on the basis of a unique specimen from the Late Ordovician Georgian Bay Formation of southern Ontario. The affinities of the organism remain obscure, although the overall morphology of component sclerites suggests a possible relationship with the Agmata, an extinct phylum-level group so far known with certainty only from the Cambrian. Curved, conical elements of the scleritome are preserved as internal moulds and yield no details of ultrastructure or primary composition, precluding detailed comparisons with the aggultinated, internally laminated sclerites of agmatans. Curviconophorus gen.nov. has a scleritome architecture similar to that of the Early Ordovician putative agmatan Dimorphoconus granulatus, though it has fewer elements that are strictly monomorphic.

New Monoplacophora (Mollusca) from Late Cambrian and Early Ordovician of Missouri

1986 ◽  
Vol 60 (3) ◽  
pp. 606-626 ◽  
Author(s):  
Bruce L. Stinchcomb
Keyword(s):  
New Species ◽  
New Genus ◽  
New Genera ◽  
New Genus And Species ◽  
Upper Cambrian ◽  
Early Ordovician ◽  
New Family ◽  
Late Cambrian ◽  
Lower Ordovician ◽  
A New Species

Fourteen new species and six new genera of the molluscan class Monoplacophora are described from the Upper Cambrian Potosi and Eminence formations and the Lower Ordovician Gasconade Formation of the Ozark Uplift of Missouri and some new biostratigraphic horizons are introduced. A new superfamily, the Hypseloconellacea nom. trans. Knight, 1956, and a new family, the Shelbyoceridae, are named. The genus Proplina is represented by five new species: P. inflatus, P. suttoni from the Cambrian Potosi Formation, P. arcua from the Cambrian Eminence Formation and P. meramecensis and P. sibeliusi from the Lower Ordovician Gasconade Formation. A new genus and species in the subfamily Proplininae, Ozarkplina meramecensis, is described from the Upper Cambrian Eminence Formation. Four new monoplacophoran genera in the superfamily Hypseloconellacea and their species are described, including: Cambrioconus expansus, Orthoconus striatus, Cornuella parva from the Eminence Formation, and Gasconadeoconus ponderosa, G. waynesvillensis, G. expansus from the Gasconade Formation. A new genus in the new family Shelbyoceridae, Archeoconus missourensis, is described from the Eminence Formation and a new species of Shelbyoceras, S. bigpineyensis, is described from the Gasconade Formation.

scholarly journals Systematic ichnology of the Late Ordovician Georgian Bay formation of southern Ontario, eastern Canada /

1998 ◽  
Author(s):  
D. Christopher A. Stanley ◽  
R. K. Pickerill ◽  
Keyword(s):  
Late Ordovician ◽  
Eastern Canada ◽  
Southern Ontario ◽  
Georgian Bay

A new cyclocystoid (Echinodermata) from the Late Ordovician of Kentucky, U.S.A.

1995 ◽  
Vol 69 (6) ◽  
pp. 1186-1187 ◽  
Author(s):  
Andrew B. Smith ◽  
Mark A. Wilson
Keyword(s):  
New Species ◽  
Functional Morphology ◽  
New Genus ◽  
Personal Communication ◽  
Late Ordovician ◽  
Late Devonian ◽  
New Genus And Species ◽  
Systematic Revision ◽  
Lower Carboniferous ◽  
Lower Ordovician

Cyclocystoids are one of the rarest and most enigmatic of the extinct echinoderm groups. Despite recent systematic revision (Smith and Paul, 1982), their basic anatomy and functional morphology remain poorly understood. Smith and Paul (1982) recognized eight genera and 39 species ranging in age from Lower Ordovician to Late Devonian. Since then, one new genus and species,Monocycloides oelandicus, has been established by Berg-Madsen (1987), and the range of the genusSievertsiahas been extended to the Middle Devonian of the U.S.A (Fluegeman and Orr, 1990). In addition, undescribed cyclocystoid marginal ossicles have been found in the Lower Carboniferous of Ireland (G. D. Sevastopulo, personal communication). Here we record an additional new species from the Late Ordovician of Kentucky.

Solving the mystery of crinoid ancestry: new fossil evidence of arm origin and development

2009 ◽  
Vol 83 (3) ◽  
pp. 350-364 ◽  
Author(s):  
Thomas E. Guensburg ◽  
James Sprinkle
Keyword(s):  
New Genus ◽  
First Record ◽  
New Genus And Species ◽  
Early Ordovician ◽  
New Family ◽  
Fossil Evidence

Apektocrinus ubaghsinew genus and species is a monospecific taxon assigned to the new family Apektocrinidae based on additional preparation of a single previously studied specimen.Apektocrinusis among the oldest known crinoids (Early Tremadoc, Early Ordovician). Although expressing crinoid apomorphies, it is interpreted as retaining plesiomorphies in its arms reflecting early edrioasteroid rather than blastozoan (eocrinoid) ancestry. Apomorphies represent basal crinoid and cladid (crownward) levels of phylogeny.Restudy fortifies previous reports of the presence of a basal echinoderm plesiomorphy; floor plates above brachials in the arms ofApektocrinus, as well as in other approximately contemporary crinoids.Apektocrinusfurnishes the first record of podial basins in crinoid arms. Arms and calyx ofApektocrinusmerge gradually, facilitated by continuations of interbrachials (extraxial body plates) extending onto the arms and separating floor plates from brachials. These arm interbrachials, which diminish and pinch out distally as floor plates nestle into the brachial (adoral) groove, have not been recognized as such in crinoids.

An unusual new sinuitid mollusc (Bellerophontoidea, Gastropoda) from the Ordovician of Spain

1996 ◽  
Vol 70 (4) ◽  
pp. 602-609 ◽  
Author(s):  
Jiří Frýda ◽  
Juan Carlos Gutiérrez-Marco
Keyword(s):  
New Genus ◽  
Outer Shell ◽  
New Genus And Species ◽  
Central Spain ◽  
Shell Surface ◽  
Middle Ordovician ◽  
Early Ordovician ◽  
Phylogenetic Relations ◽  
The Family ◽  
Mode Of Life

Hispanosinuites peeli new genus and species from the Lower Oretan shales (Middle Ordovician) of central Spain is described and placed in the new subfamily Hispanosinuitinae of the family Sinuitidae. This new subfamily is considered to represent a highly specialized phylogenetic lineage, which probably separated from the morphological range of the genus Sinuites during the Early Ordovician. The outer shell surface of Hispanosinuites peeli is entirely covered by secondary shell layers, which are interpreted as perinductura, inductura and coinductura. The similarity of these shell deposits in Hispanosinuites peeli and species of Euphemites suggests that these layers were secreted by mantle flaps having the same form in both genera. Hispanosinuites peeli is interpreted as a mobile mollusc with an internal shell adapted to an infaunal mode of life. Discovery of this unusual mollusc reopens the question of the phylogenetic relations of the families Sinuitidae and Euphemitidae, which are often assigned to different molluscan classes.

New Late Ordovician (Early Caradoc) bivalves from the Sierra de Villicum (Argentine Precordillera)

1999 ◽  
Vol 73 (1) ◽  
pp. 66-76 ◽  
Author(s):  
Teresa M. Sánchez
Keyword(s):  
New Species ◽  
New Genus ◽  
Late Ordovician ◽  
Bivalve Molluscs ◽  
New Genus And Species ◽  
The Matrix ◽  
Argentine Precordillera

A new and unusually well preserved bivalve fauna of Late Ordovician age was recovered from pebbles within the Late Ashgill (Hirnantian) glacigenic diamictite of the Don Braulio Formation, in the Argentine Precordillera. According to the associated brachiopods and the presence of graptolites of the bicornis Zone in the matrix of the diamictite, an early Caradoc age is accepted for the bivalve fauna. The clasts contain bivalve molluscs representing nine genera, of which seven are new. Identified taxa are the following: Praenucula sp., Cuyopsis symmetricus new genus and species, Villicumia canteraensis new genus and species, Trigonoconcha acuta new genus and species, Concavodonta ovalis new species, Hemiconcavodonta minuta new genus and species, Hemiconcavodonta sp., Emiliania cuerdae new genus and species, and Concavoleda braulense new genus and species. Two new subfamilies are proposed: Praenuculinae and Concavodontinae. The genera Praenucula Pfab, Cuyopsis new genus, Villicumia new genus, and Trigonoconcha new genus are included in the new subfamily Praenuculinae. The genera Concavodonta Babin and Melou, Hemiconcavodonta new genus, and Emiliania new genus are included in the new subfamily Concavodontinae.

scholarly journals A new Ordovician astylospongiid sponge (Porifera) as an erratic from Baltica

2004 ◽  
Vol 83 (4) ◽  
pp. 255-265 ◽  
Author(s):  
F. Rhebergen
Keyword(s):  
New Genus ◽  
Drainage System ◽  
Late Ordovician ◽  
Early Pleistocene ◽  
New Genus And Species ◽  
Baltic Region ◽  
Northern Germany ◽  
Upper Pleistocene ◽  
The North ◽  
The Baltic

AbstractUntil now hemispherical astylospongiid sponges were invariably referred to as Caryospongia juglans var. basiplana Rauff. Renewed investigations have now shown that part of the material should be assigned to a new genus and species, Tympanospongia vankempeni, which is characterised by a system of very irregular canals. These flat-based sponges originate from the Baltic region and occur in two assemblages of silicified Late Ordovician sponges known exclusively as erratics from The Netherlands and northern Germany. These fossils were transported by the River Eridanos, a former drainage system from the Baltic region that filled the North European Basin during the Miocene to Early Pleistocene. Specimens of Tympanospongia vankempeni gen. et sp. nov. also occur in the Upper Pleistocene of Gotland, Sweden. The new sponge described herein principally differs from other genera of the Astylospongiidae found frequently in the erratic sponge assemblages by its irregular system of apochetes which ramify and anastomose commonly.

Storm-deposited sandstones (tempestites) and related ichnofossils of the Late Ordovician Georgian Bay Formation, southern Ontario, Canada

1991 ◽  
Vol 28 (2) ◽  
pp. 266-282 ◽  
Author(s):  
Michael Kerr ◽  
Nicholas Eyles
Keyword(s):  
Foreland Basin ◽  
Detailed Examination ◽  
Middle Part ◽  
Late Ordovician ◽  
Southern Ontario ◽  
Georgian Bay ◽  
Fine Grained ◽  
Delta Plain ◽  
Niagara Escarpment ◽  
Taconic Orogeny

The Late Ordovician Geogian Bay Formation of southern Ontario, Canada, comprises up to 250 m of grey to blue–grey shales interbedded with highly fossiliferous calcareous sandstones. These strata were deposited in equatorial paleolatitudes after 448 Ma in a shallow foreland basin created by overthrusting along the eastern margin of North America (the Taconic orogeny). The Georgian Bay Formation comprises the middle part of an upward-shallowing progradational sequence from deep-water transgressive shales of the underlying Whitby Formation to muddy tidal-flat sequences of the overlying Queenston Formation. Exposures in brickyard and river cuts near Toronto, and northwards along a narrow outcrop belt along the foot of the Niagara Escarpment, show laterally extensive (100 m+), sharp-based sheets of sandstone up to 1 m thick, with gutter casts and washed-out (hypichnial) trace fossils (dominantly Planolites and Paleophycus) on their lower bedding surfaces. Detailed examination of sandstone beds in outcrop and in three boreholes that penetrate the formation shows that the beds are composed internally of a basal fossil hash layer overlain by flat, hummocky, and wave-rippled divisions. Bed tops show a variety of wave-ripple forms and are heavily bioturbated (dominantly Bifungites, Conostichus, Diplocraterion, Didymaulichnus, Teichichnus). Sandstone sheets are interpreted as storm deposits (tempestites) resulting from tropical storms (hurricanes) transporting fine-grained suspended sediment from a delta plain onto a muddy shelf to the west.

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