Early Devonian (late Emsian) Brachiopods from Zhongping, Xiangzhou, central Guangxi, China

1999 ◽  
Vol 79 (1) ◽  
pp. 223-265 ◽  
Author(s):  
Xiu-Qin Chen ◽  
Zhao-Gui Yao
Keyword(s):  
Early Devonian ◽  
Late Emsian

New Early Devonian pteraspidids (Agnatha, Heterostraci) from Death Valley National Monument, southeastern California

1996 ◽  
Vol 70 (1) ◽  
pp. 152-161 ◽  
Author(s):  
David K. Elliott ◽  
Robert R. Ilyes
Keyword(s):  
Estuarine Environment ◽  
Death Valley ◽  
Early Devonian ◽  
National Monument ◽  
Bearing Unit ◽  
Late Emsian

Two species and genera of pteraspidids (Agnatha, Heterostraci), Blieckaspis priscillae n. gen., and Panamintaspis snowi n. gen. and n. sp., together with two undetermined species, are described from the lower part of the Lippincott Member of the Lost Burro Formation, southeastern California. The sharing of similar faunal elements with the Early Devonian assemblages of the Sevy Dolomite and Water Canyon Formation of Utah and Nevada, respectively, together with stratigraphic constraints on the age of the Death Valley fauna, suggest that these assemblages are age equivalent and have a late Emsian (inversus–serotinus Zones) age. The vertebrate-bearing unit of the Lippincott Member is interpreted as a channel-fill deposit laid down in an estuarine environment with low or fluctuating salinity.

The dipnoan species, Sorbitorhynchus deleaskitus , from the Lower Devonian of Guangxi, China

1993 ◽  
Vol 340 (1291) ◽  
pp. 1-24 ◽  
Keyword(s):  
Lower Devonian ◽  
Early Devonian ◽  
Hyoid Arch ◽  
New Perspective ◽  
Dermal Bones ◽  
Late Emsian

A dipnoan species from the Emsian of Guangxi, China, Sorbitorhynchus deleaskitus , which has previously been diagnosed in the appendix to a more general paper on dipnoan phylogeny (Cambell & Barwick 1990), is described in detail. The head is large and heavily ossified, with cosmine on the external dermal bones. The dental plates are thick and have few poorly defined large tuberosities towards their anterolateral edges. It is the only Early Devonian dipnoan for which the full hyoid arch, gular, basibranchial, and submandibular plates are preserved, and in which the parasphenoid is clearly defined. In many features the genus is more advanced than Dipnorhynchus , but in none is it more advanced than Dipterus , apart from the loss of the buccohypophysial foramen. It gives a new perspective on late Emsian evolution of the group, and reinforces our concept of an independently developing dentine-plated line contemporaneous with a true tooth-plated line.

scholarly journals Early Devonian (Late Emsian) shark fin remains (Chondrichthyes) from the Paraná Basin, southern Brazil

2017 ◽  
Vol 89 (1) ◽  
pp. 103-118 ◽  
Author(s):  
MARTHA RICHTER ◽  
ELVIO P. BOSETTI ◽  
RODRIGO S. HORODYSKI
Keyword(s):  
Southern Brazil ◽  
Early Devonian ◽  
Paraná Basin ◽  
Parana Basin ◽  
Late Emsian

Early Devonian Spores from Central Ellesmere Island, Canadian Arctic

1974 ◽  
Vol 11 (1) ◽  
pp. 70-78 ◽  
Author(s):  
D. C. McGregor
Keyword(s):  
Canadian Arctic ◽  
Ellesmere Island ◽  
Early Devonian ◽  
Late Emsian

The Vendom Fiord Formation near the head of Cañon Fiord, central Ellesmere Island, hitherto thought to be unfossiliferous, contains mid to late Emsian trilete spores. Strata below the Vendom Fiord Formation, separated from it by an unconformity, contain a less diverse assemblage of spores that suggests a mid to late Gedinnian age. The spores are the only fossils known from these beds, and the first palynomorphs to be reported from the Early Devonian rocks of Ellesmere Island.

Microforaminiferal linings from the Early Devonian of eastern Australia, and their generic placement

1994 ◽  
Vol 68 (2) ◽  
pp. 200-207 ◽  
Author(s):  
Theresa Winchester-Seeto ◽  
K. N. Bell
Keyword(s):  
New South ◽  
New South Wales ◽  
Early Devonian ◽  
Wall Lining ◽  
South Wales ◽  
Eastern Australia ◽  
Late Emsian

Microforaminiferal linings assigned to 10 known genera have been recovered from Early Devonian (Lochkovian to Late Emsian) limestones from Victoria, New South Wales, and Queensland. These organic linings have been identified by comparison with normal-sized agglutinated foraminiferan genera known to occur in the associated sediments. Microforaminiferal linings with smooth walls and reticulate sculptured walls were present and the possible implications of these (diagenetic, relict structure, naked homeomorphs, or processing artifact) are discussed. Evidence is presented thatOrdovicinamay have a bilamellar organic wall lining.

Early Devonian calymenid larvae (Trilobita) from the Bissounel Formation (Montagne Noire, France)

2007 ◽  
Vol 178 (3) ◽  
pp. 197-200 ◽  
Author(s):  
Rudy Lerosey-Aubril
Keyword(s):  
Larval Stage ◽  
Morphological Characteristics ◽  
Developmental Strategy ◽  
Two Stage ◽  
Early Devonian ◽  
Montagne Noire ◽  
Middle Member ◽  
Planktonic Larval Stage ◽  
Late Emsian ◽  
Comparable Size

AbstractThe late Emsian middle Member of the Bissounel Formation (Montagne Noire, France) has yielded a highly diverse silicified trilobite fauna. Among the thousands of disarticulated sclerites discovered, two protaspid specimens were found that display morphological characteristics of planktonic larvae of calymenid trilobites. The presence of calymenid protaspides within a non-calymenid trilobite fauna is noted. The two specimens are very similar to the first planktonic larval stage of the Ordovician Flexicalymene senaria (Conrad, 1841), and are of comparable size. This indicates that, as in F. senaria, a second planktonic larval stage might have occurred in the ontogeny of this undetermined calymenid. Thus, some post-Ordovician calymenids might have retained the ancestral developmental strategy with a two-stage planktonic period. The discovery of these two protaspides constitutes the first evidence of a calymenid trilobite in the Devonian of the Montagne Noire.

Stratigraphy and tectono-sedimentary evolution of the Late Ordovician to Middle Devonian Gaspé Belt in northern New Brunswick: evidence from the Restigouche area

2004 ◽  
Vol 41 (5) ◽  
pp. 527-551 ◽  
Author(s):  
Reginald A Wilson ◽  
Elliott T Burden ◽  
Rudolf Bertrand ◽  
Esther Asselin ◽  
Alexander D McCracken
Keyword(s):  
Volcanic Rocks ◽  
Extended Period ◽  
West Point ◽  
Upper Ordovician ◽  
Early Devonian ◽  
Lower Silurian ◽  
Sedimentary Evolution ◽  
Indian Point ◽  
High Level ◽  
Late Emsian

The Gaspé Belt in the Restigouche area comprises three successions separated by a Late Silurian (Salinic) disconformity and an Early Devonian angular unconformity. The lower, Upper Ordovician to Lower Silurian sequence consists of siliciclastic turbidites of the Boland Brook and Whites Brook formations (Grog Brook Group), overlain by calcareous turbidites of the Pabos and White Head formations (Matapédia Group), and slope and shelf deposits of the Upsalquitch and Limestone Point formations (lower Chaleurs Group). Above the Salinic disconformity, the upper Chaleurs Group and the Dalhousie Group record a transgressive–regressive cycle. The former comprises Pridolian carbonate rocks of the West Point Formation and overlying Pridolian to Lochkovian sedimentary rocks of the Indian Point Formation. The Chaleurs Group is conformably overlain by Lochkovian to early Emsian subaerial volcanic rocks of the Dalhousie Group (Val d'Amour Formation), which is unconformably overlain by alluvial–lacustrine deposits of the late Emsian Campbellton Formation. Acadian orogenesis began during the Emsian and is characterized by open to closed folding, heterogenous cleavage development, and reverse and strike-slip faults. The Salinic orogeny is manifested in extensional block faulting, within-plate volcanism, and uplift and deep erosion of Early Silurian strata. Early Devonian high-level intrusion of the Matapédia Group, White Head clasts in Indian Point conglomerate, and thermal maturation data all indicate an extended period of Late Silurian – Early Devonian uplift in parts of the Restigouche area. Thermal maturities of West Point and Indian Point strata are within the oil and condensate windows and suggest potential for hydrocarbons in the study area.

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