Paleoecology of selected conodontophorid species from the Cobbs Arm Formation (middle Ordovician), New World Island, north-central Newfoundland

1981 ◽  
Vol 18 (11) ◽  
pp. 1653-1665 ◽  
Author(s):  
Lars E. Fåhræus ◽  
David R. Hunter
Keyword(s):  
New World ◽  
North Central ◽  
Reciprocal Relationships ◽  
Volcanic Material ◽  
Middle Ordovician ◽  
Sediment Types ◽  
Speciation Event ◽  
Low Diversity ◽  
Current Energy ◽  
Very High

The upper Chazyan (Llandeilian) Cobbs Arm Formation of New World Island, north-central Newfoundland, consists of pure limestones and limestones with varying amounts of volcaniclastic admixture interbedded with calcareous tuff. The depositional environment for the Cobbs Arm Formation was that of a volcanic island arc waning in volcanic activity. A rich and varied conodontophorid fauna has been identified from the limestones. Conodontophorid diversity is low in the limestones with high volcaniclastic admixtures; these were probably deposited in a nearshore, but not necessarily very shallow, environment. Farther offshore where there was less or no admixture of volcanic material the diversity is found to be the highest. Samples from environments of very high wave or current energy show very low diversity or are entirely lacking in conodonts. Distributions of individual conodontophorid species show repetitive patterns with regard to co-occurrences, reciprocal relationships, mutually exclusive occurrences, and correlations with sediment types. The paleoecology of the following species is discussed: Baltoniodus prevariabilis–B. variabilis transition, B. variabilis, Eoplacognathus lindstroemi, E. robustus, Panderodus gracilis, Periodon aculeatus, Protopanderodus varicostatus, Pygodus anserinus, P. serrus, Strachanognathus parva, Walliserodus ethingtoni, and W. nakholmensis. The biostratigraphic implications with particular regard to P. serrus and P. anserinus are discussed and it is concluded that the P. serrus–P. anserinus transition (speciation event) probably has less chronostratigraphic value than previously assumed.

Simple-cone conodont taxa from the Cobbs Arm Limestone (Middle Ordovician), New World Island, Newfoundland

1985 ◽  
Vol 22 (8) ◽  
pp. 1171-1182 ◽  
Author(s):  
Lars E. Fåhræs ◽  
David R. Hunter
Keyword(s):  
New Taxa ◽  
Type Species ◽  
New World ◽  
North Central ◽  
Middle Ordovician ◽  
Simple Cone

New and previously described conodont taxa are reported from the upper Chazyan (Llandeilian) Cobbs Arm Limestone of New World Island, north-central Newfoundland. In addition to Ansellidae n. fam., (the following new taxa are described: Ansella n. gen., with type species Belodella jemtlandica Löfgren, 1978, Goverdina alicula n. gen. n. sp., Serraculodus alveus n. gen. n. sp., and Walliserodus dolabellus n. sp. The conodont apparatus compositions of the following species are also described: Ansella nevadensis (Ethington and Schumacher), Scalpellodus cavus (Webers), Walliserodus ethingtoni (Fåhræs), and W. nakholmensis (Hamar).

scholarly journals Origin, diversity and distribution of freshwater epigean amphipods in Maghreb

2019 ◽  
Vol 55 ◽  
pp. 13 ◽  
Author(s):  
Khaoula Ayati ◽  
Ramzi Hadjab ◽  
Hichem Khammar ◽  
Sonia Dhaouadi ◽  
Christophe Piscart ◽  
...  
Keyword(s):  
Northern Africa ◽  
High Rate ◽  
Conservation Strategies ◽  
Undescribed Species ◽  
General Lack ◽  
The World ◽  
Low Diversity ◽  
Freshwater Amphipods ◽  
Freshwater Fauna ◽  
Very High

Northern Africa, although one of the world hotpots of biodiversity, is poorly studied and the freshwater fauna living in this part of the world remains partly unknown. This study focused on the diversity and distribution of the poorly known epigean freshwater amphipods. We performed an exhaustive analysis of the literature on this group of crustaceans and sampled 106 additional localities from the eastern part of Algeria and in Tunisia. Our results showed an important diversity with 25 species (including the presence of at least three new undescribed species) and a very high rate of endemism with 52% of species occurring at on only 1 or 2 sites. We also highlighted a very low diversity on each site with only 4.4% of sites harboring more than 1 species. The comparative distribution of certain species between Europe and Maghreb and also between the western and eastern part of Northern Africa allow us to discuss some hypotheses about the factors underlying this endemism and the biogeographical origin of species. However, our study revealed a general lack of knowledge in the region, especially in the South of Morocco and Algeria. Hence, more information would be needed to propose adapted conservation strategies of freshwater fauna in Maghreb.

Middle Ordovician Echinoderms from Northern Illinois and Southern Wisconsin

1975 ◽  
Vol 49 (S7) ◽  
pp. 1-74 ◽  
Author(s):  
Dennis R. Kolata
Keyword(s):  
New Species ◽  
New Genus ◽  
Carbonate Sediments ◽  
North Central ◽  
Middle Ordovician ◽  
South Central ◽  
The Family ◽  
Central Illinois ◽  
First Time ◽  
One New Species

Echinoderms of the Middle Ordovician Platteville and lower Galena Groups of north-central Illinois and south-central Wisconsin are represented by at least seven classes including the Homoiostelea, Cystoidea, Crinoidea, Stelleroidea, Edrioasteroidea, Cyclocystoidea, Echinoidea, and possibly Holothuroidea. The most abundant and diverse echinoderms are monocyclic and dicyclic inadunate and camerate crinoids, of which the cupulocrinids and glyptocrinids are best represented. Thirteen new species and one new genus of crinoids are described:Cremacrinus guttenbergensis, Anulocrinus forrestonensis, Isotomocrinus minutus, Carabocrinus oogyi, Dendrocrinus? springeri, Merocrinus britonensis, Cupulocrinus plattevillensis, C. molanderi, Reteocrinus rocktonensis, R. spinosus, Traskocrinus mahlburgi(n. gen. et sp.),Rhaphanocrinus buckleyi, Glyptocrinus charltoni, andG. pustulosis.One new species of rhombiferan cystoid,Coronocystis durandensis, is also described. Echinoids of the family Bothriocidaridae (Bothriocidaris solemin. sp. andNeobothriocidaris templetonin. sp.) are reported for the first time from North America and appear to be the earliest recorded occurrence. Remains of a third bothriocidarid characterized by coalesced podial pores have also been discovered. Light and scanning electron microscopy of well preserved cyclocystoid specimens reveal a number of previously undescribed morphologic features of the central disc and submarginal ring that may shed some light on their functional morphology.Cupulocrinus gracilisRamsbottom from the Upper Drummuck Group Starfish Bed at Thraive Glen near Girvan, Scotland, is here reassigned toC. drummuckensisn. sp.Echinoderms are associated with an abundant and diverse fauna consisting largely of suspension feeders, primarily strophomenid and orthid brachiopods and trepostome and cryptostome bryozoans. Other common groups include corals, trilobites, sponges, and mollusks. Filamentous brown, foliose red and siphonaceous green algae are associated with the fauna at some localities.Carbonate rocks of both the limestone and dolostone facies of the Platteville (Briton, Walgreen and Forreston Members) and lower Galene Groups in the study area consist primarily of abundant shelly invertebrates occurring as whole and broken, unabraded, commonly articulated remains “floating” in a calcisiltite matrix that is highly bioturbated. Carbonate sediments appear to have been deposited in a near-to below wave base, highly stable, open marine environment characterized by low depositional slopes, good circulation and low terrigenous influx.

Early radiation of echinoderms

1997 ◽  
Vol 3 ◽  
pp. 205-224 ◽  
Author(s):  
James Sprinkle ◽  
Thomas E. Guensburg
Keyword(s):  
Mass Extinction ◽  
Fossil Record ◽  
Early Paleozoic ◽  
Soft Substrate ◽  
Middle Cambrian ◽  
Middle Ordovician ◽  
Late Cambrian ◽  
Low Diversity ◽  
Early Radiation ◽  
Ways Of Life

Echinoderms underwent a major two-part radiation that produced all of the major groups found in the fossil record between the Early Cambrian and the Middle Ordovician. A small initial radiation in the Early and Middle Cambrian produced about nine classes containing low-diversity members of the Cambrian Evolutionary Fauna. These were characterized by primitive morphology, simple ambulacral feeding structures, and the early development of a multiplated stalk or stem for attachment to skeletal fragments on a soft substrate. Several groups became extinct at the end of the Middle Cambrian, leaving the Late Cambrian as a gap of very low diversity in the fossil record of echinoderms with only four classes preserved and very few occurrences of complete specimens, mostly associated with early hardgrounds. The survivors from this interval re-expanded in the Early Ordovician and were joined by many newly evolved groups to produce a much larger radiation of more advanced, diverse, and successful echinoderms representing the Paleozoic Evolutionary Fauna on both hard and soft substrates. At least 17 classes were present by the Middle Ordovician, the all-time high point for echinoderm class diversity, and nearly all of the major ways-of-life (except for deep infaunal burrowing) had been developed. With the rise to dominance of crinoids, many less successful or archaic groups did not survive the Middle Ordovician, and echinoderm class diversity dropped further because of the mass extinction at the end of the Ordovician. This weeding-out process of other less-successful echinoderm groups continued throughout the rest of the Paleozoic, and only five classes of echinoderms have survived to the Recent from this early Paleozoic radiation.

First evidence of Lower–?Middle Ordovician (Floian–?Dapingian) brachiopods from the Peruvian Altiplano and their paleogeographical significance

2020 ◽  
Vol 95 (1) ◽  
pp. 56-74
Author(s):  
Jorge Colmenar ◽  
Eben Blake Hodgin
Keyword(s):  
New Species ◽  
South China ◽  
New World ◽  
New Genus ◽  
Island Arcs ◽  
Low Latitude ◽  
Middle Ordovician ◽  
Iapetus Ocean ◽  
Well Differentiated ◽  
One New Species

AbstractThe lower strata of the Umachiri Formation from the Altiplano of southeast Peru have yielded a brachiopod-dominated assemblage, containing representatives of the brachiopod superfamilies Polytoechioidea, Orthoidea, and Porambonitoidea, as well as subsidiary trilobite and echinoderm remains. Two new polytoechioid genera and species, Enriquetoechia umachiriensis new genus new species and Altiplanotoechia hodgini n. gen. n. sp. Colmenar in Colmenar and Hodgin, 2020, and one new species, Pomatotrema laubacheri n. sp., are described. The presence of Pomatotrema in the Peruvian Altiplano represents the occurrence at highest paleolatitude of this genus, normally restricted to low-latitude successions from Laurentia and South China. Other polytoechioids belonging to Tritoechia (Tritoechia) and Tritoechia (Parvitritoechia) also occur. Identified species of orthoids from the genera Paralenorthis, Mollesella, and Panderina? occur in the Peruvian Cordillera Oriental and in the Argentinian Famatina Range. The only porambonitoid represented is closely related to Rugostrophia latireticulata Neuman, 1976 from New World Island, interpreted as peri-Laurentian. These brachiopod occurrences indicate a strong biogeographic affinity of the Peruvian Altiplano with the Famatina and western Puna regions, suggesting that the brachiopod faunas of the Peruvian Altiplano, Famatina, and western Puna belonged to a well-differentiated biogeographical subprovince during the Early–Middle Ordovician on the margin of southwestern Gondwana. Links with peri-Laurentian and other low-latitude terranes could be explained by island hopping and/or continuous island arcs, which might facilitate brachiopod larvae dispersal from the Peruvian Altiplano to those terranes across the Iapetus Ocean. Brachiopods from the lower part of the Umachiri Formation indicate a Floian–?Dapingian age, becoming the oldest Ordovician fossils of the Peruvian Altiplano.UUID: http://zoobank.org/9670a000-260d-4d75-9261-110854c7afb8

Excavations on the Site of the Priory Church and Monastery of St. Peter, Eye, Suffolk

1927 ◽  
Vol 7 (3) ◽  
pp. 299-312
Author(s):  
F. H. Fairweather
Keyword(s):  
Small Town ◽  
Previous History ◽  
Norman Conquest ◽  
North Central ◽  
Suitable Site ◽  
Edward The Confessor ◽  
Very High ◽  
Maternal Side

The small town of Eye in north central Suffolk was one of those feudal centres which sprang into great importance on the redistribution of English lands following the Norman Conquest. It had, however, a previous history as head of an Honour, being held as such in the reign of Edward the Confessor by Edric the king's falconer, and was thus chosen as a suitable site for the establishment of one of the Conqueror's prominent barons, and granted to William Malet. This man was Sire de Graville, a small town a little east of Havre in Normandy, where the priory church founded by his grandson William, and some remains on the site of the Malet castle, still exist on a height overlooking the Seine. He was apparently of English birth on the maternal side and of very high family, his mother being a sister of the famous Godiva, wife of Leofric Earl of Mercia, and was thus one of those Normans who had definite pre-Conquest connexions with Saxon England.

scholarly journals Keanekaragaman JenisTumbuhan Paku (Pteridophyta) di Jalur Pendakian Selo Kawasan Taman Nasional Gunung Merbabu, Jawa Tengah

2017 ◽  
Vol 19 (2) ◽  
pp. 119
Author(s):  
Fitri Kusuma Astuti ◽  
M Murningsih ◽  
J Jumari
Keyword(s):  
Forest Ecosystem ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
National Park ◽  
Diversity Index ◽  
High Mountains ◽  
Key Word ◽  
Low Diversity ◽  
The Many ◽  
Very High

Indonesia has a very high biodiversity, as well as ferns (Pteridophyta).Selo climbing lane at Merbabu Montain Nasional Park selected as the study site because of the many ferns that were founded in this area.The purpose of this study was to analyze the diversity of ferns species.in tropical rain forest ecosystem of high mountains and sub-alpine forests ecosystem on Selo climbing lane at Merbabu Mount National Park. There are many human activity in Selo climbing lanesupposed to influence the existing plants. This research was held on August-December 2016. The method usedinventory inSelo climbing lane and Plot, then analyzed using diversity index. The results found 33 species of ferns from 15 families. The diversity of ferns in the tropical rain forest ecosystem of high mountains fall into the medium category except at post II (2412 masl) has low diversity. Diversity in the sub-alpine forest ecosystem can not be calculated. Key word: diversity, fern, Selo climbing lane

Fe- and Mn-Enrichment in Middle Ordovician Hematitic Argillites Preceding Black Shale and Flysch Deposition: The Shoal Arm Formation, North-Central Newfoundland

1994 ◽  
Vol 102 (2) ◽  
pp. 197-214 ◽  
Author(s):  
Volker Brüchert ◽  
John W. Delano ◽  
William S. F. Kidd
Keyword(s):  
Black Shale ◽  
North Central ◽  
Middle Ordovician ◽  
Fe And Mn

Subspeciation within a punctuated equilibrium evolutionary event: Phylogenetic history of the Lower-Middle Ordovician Paroistodus originalis—P. horridus complex (Conodonta)

2000 ◽  
Vol 74 (3) ◽  
pp. 492-502
Author(s):  
Guillermo L. Albanesi ◽  
Christopher R. Barnes
Keyword(s):  
Carbonate Platform ◽  
Black Shales ◽  
San Juan ◽  
Carbonate Production ◽  
Middle Ordovician ◽  
Lower Member ◽  
Speciation Event ◽  
Restricted Environment ◽  
Evolutionary Event ◽  
Middle Member

A microevolutionary event involving the conodont Paroistodus lineage is documented in the Gualcamayo Formation (Middle Ordovician), Argentine Precordillera. A detailed sampling of limestones throughout the upper part of the San Juan Formation and the lower member of the Gualcamayo Formation yielded over 14,000 well-preserved conodont elements. Paroistodus originalis (Sergeeva, 1963) was recorded through the upper 230 m of the San Juan Formation and the lower member (10 m thick) of the Gualcamayo Formation. The derived species Paroistodus horridus (Barnes and Poplawski, 1973) was recorded throughout the middle member of the Gualcamayo Formation (65 m thick). The intermediate linking forms between both species are identified as two new taxa: Paroistodus horridus primus Albanesi, 1998b, and P. h. secundus Albanesi, 1998b. They were recorded in the uppermost 70 cm of the lower member. Apparently, the speciation event occurred under stressed environmental conditions with the drowning of the carbonate platform, i.e., the San Juan Formation, and the beginning of a deeper and restricted environment represented by the Gualcamayo black shales. The demise of the carbonate production was caused by a sea level rise and a significant influx of volcanic ashes. The punctuated speciation event occurred within an allopatric setting while the Precordillera occupied an isolated (Iapetus) oceanic position in its overall drift from Laurentia to Gondwana.

Sign in / Sign up

Export Citation Format

Share Document