Late Devonian conodonts define the precise horizon of the Frasnian–Famennian boundary at Cinquefoil Mountain, Jasper, Alberta

1995 ◽  
Vol 32 (11) ◽  
pp. 1825-1834 ◽  
Author(s):  
K. Wang ◽  
H. H. J. Geidsetzer

Conodonts from carbonate slope sediments of the Ronde Member at Cinquefoil Mountain near Jasper, Alberta, have constrained the Frasnian–Famennian boundary in the Upper Devonian for the first time in Canada. Based on conodont Palmatolepis species, the Frasnian–Famennian boundary has been precisely identified in this section at the base of a tempestite bed (20 cm thick), 14 m above the base of the Ronde Member and directly below a prominent oncolite bed (65 cm thick). Recognized standard conodont zones are the Upper rhenana–linguiformis (or Montagne Noire Zone 13), the Lower triangularis, and the Middle triangularis zones. Conodonts exhibit a mixed Palmatolepis–Polygnathus–Icriodus biofacies, supporting the paleogeographic interpretation of this site as an upperslope depositional setting along the southeastern margin of the paleo-Jasper Basin.

2012 ◽  
Vol 63 (5) ◽  
pp. 355-363 ◽  
Author(s):  
Atike Nazik ◽  
Șenol Çapkinoğlu ◽  
Emine Șeker

Abstract Famennian (Late Devonian) ostracods of the Thuringian Mega-Assemblage were recovered for the first time from three incomplete sections of the Ayineburnu Member of the Büyükada Formation in the Denizliköy area (Gebze, NW Turkey), which were sampled for conodonts. Conodont faunas define an interval extending from the Upper rhomboidea? or Lower marginifera Zone into the Middle expansa Zone of the standard Upper Devonian conodont zonation. The ostracod faunas found here consist of species mainly with thin-walls, long spines and often smooth surfaces such as Rectonaria, Tricornina, Orthonaria, Triplacera, Beckerhealdia, Timorhealdia, Bohemina, Paraberounella and Acratia. These taxa indicate faunal relationship with Thuringia and the Rhenish Massif in Germany, the Cantabrian Mountains and Pyrenees in Spain, Holy Cross Mountains in Poland, North Africa and China.


2018 ◽  
Vol 488 (1) ◽  
pp. 181-204 ◽  
Author(s):  
R. Ellen ◽  
M. A. E. Browne ◽  
A. J. Mitten ◽  
S. M. Clarke ◽  
A. G. Leslie ◽  
...  

AbstractThe Spireslack surface coal mine exposes a section in the Carboniferous Lawmuir Formation (Brigantian) into the Upper Limestone Formation (Arnsbergian). This paper describes the stratigraphy exposed at Spireslack and, in so doing, names for the first time the Spireslack Sandstone, a distinctive erosively based, sandstone-dominated unit in the Upper Limestone Formation. The Spireslack Sandstone consists of two fluvial sandstone channel sets and an upper, possibly fluvio-estuarine, succession. From an analysis of their internal architectural elements, the channel sets are interpreted as a low-sinuosity, sand-dominated, mixed-load fluvial system in which avulsion and variations in sediment load played a significant part. The lower channel set appears to be confined to erosional palaeovalleys of limited lateral extent and significant relief. The upper channel set is much more laterally extensive and shows evidence of a generally lower sediment load with a greater degree of lateral accretion and flooding. Consequently, the Spireslack Sandstone may represent a system responding to base level changes of higher magnitude and longer duration than the glacio-eustatic scale commonly attributed to Carboniferous fluvio-deltaic cycles. The Spireslack Sandstone may represent an important correlative marker in the Carboniferous of the Midland Valley and may provide an alternative analogue for some Carboniferous fluvial sandstone stratigraphic traps.


2018 ◽  
Vol 156 (5) ◽  
pp. 801-810 ◽  
Author(s):  
JEFFREY R. THOMPSON ◽  
TIMOTHY A. M. EWIN

AbstractMany of the most diverse clades of Late Palaeozoic echinoids (sea urchins) originated in the Devonian period. Our understanding of diversity dynamics of these Late Palaeozoic clades are thus informed by new systematic descriptions of some of their earliest members. The Proterocidaridae are a diverse and morphologically distinct clade of stem group echinoids with flattened tests and enlarged adoral pore pairs, which are first known from the Upper Devonian. We herein report on a new species of Hyattechinus, Hyattechinus anglicus n. sp., from the Upper Devonian of the North Devon Basin, Devon, UK. This is the first Devonian Hyattechinus known from outside of the Appalachian Basin, USA, and provides novel information regarding the palaeogeographic and stratigraphic distribution of proterocidarids in Late Devonian times. We additionally update the stratigraphic distribution of Devonian Hyattechinus from the Appalachian Basin, following recent biostratigraphic resolution of their occurrences. Hyattechinus appears to have been present in the Rheic echinoderm fauna during Late Devonian times, and comparison of the palaeoenvironmental setting of Hyattechinus anglicus with that of other Hyattechinus from the Famennian of the Appalachian Basin suggests that the genus may have preferred siliciclastic settings. Furthermore, this new taxon increases the diversity of echinoids from the Upper Devonian of Devon to three species.


2019 ◽  
Vol 6 (5) ◽  
pp. 182087 ◽  
Author(s):  
Jennifer A. Clack ◽  
Marcello Ruta ◽  
Andrew R. Milner ◽  
John E. A. Marshall ◽  
Timothy R. Smithson ◽  
...  

The enigmatic tetrapod Acherontiscus caledoniae from the Pendleian stage of the Early Carboniferous shows heterodontous and durophagous teeth, representing the earliest known examples of significant adaptations in tetrapod dental morphology. Tetrapods of the Late Devonian and Early Carboniferous (Mississippian), now known in some depth, are generally conservative in their dentition and body morphologies. Their teeth are simple and uniform, being cone-like and sometimes recurved at the tip. Modifications such as keels occur for the first time in Early Carboniferous Tournaisian tetrapods. Acherontiscus , dated as from the Pendleian stage, is notable for being very small with a skull length of about 15 mm, having an elongate vertebral column and being limbless. Cladistic analysis places it close to the Early Carboniferous adelospondyls, aïstopods and colosteids and supports the hypothesis of ‘lepospondyl’ polyphyly. Heterodonty is associated with a varied diet in tetrapods, while durophagy suggests a diet that includes hard tissue such as chitin or shells. The mid-Carboniferous saw a significant increase in morphological innovation among tetrapods, with an expanded diversity of body forms, skull shapes and dentitions appearing for the first time.


2000 ◽  
Vol 74 (1) ◽  
pp. 25-31 ◽  
Author(s):  
William A. Shear

A new trigonotarbid arachnid, Gigantocharinus szatmaryi new genus and species, is described from Upper Devonian (Late Famennian) sediments in Pennsylvania. Devonian trigonotarbids were known before from only a single North American locality and several European ones. The new trigonotarbid occurs in what had previously been a significant time gap between the faunas of the Middle Devonian and the late Carboniferous. Gigantocharinus szatmaryi is assigned with some hesitation to the family Palaeocharinidae.


1998 ◽  
Vol 89 (3) ◽  
pp. 135-143 ◽  
Author(s):  
J. Javier Álvaro ◽  
Emmanuelle Vennin ◽  
Daniel Vizcaïno

AbstractLower Cambrian shallow-water carbonates enclosing microbial structures are documented for the first time from the upper Lastours Member of the Montagne Noire (southern France). Microbial organisms constructed self-supported boundstones resulting in the formation of exclusively microbial-accreted buildups, which exhibit three main types of non-skeletal microbialites: planar stratiform stromatolites, dome-shaped stromatolites and nonlaminated (thrombolitic) biostromes. In addition, thrombolitic boundstones display four distinct microbial microstructures: clotted andRenalcis-like forms, branching bushy forms, clusters of unbranching straight filaments and crustose forms.The upper member of the Lastours Formation records an upward transition from a shalydominant open shelf to a protected shelf environment bounded by a surface representing a major subaerial exposure. Initially, at the inception of the highstand systems tract, flat stratiform stromatolites formed on open sea subtidal shaly substrates, while stacked domal stromatolites developed in peritidal areas which record subaerial exposure. In contrast, prograding shoal barriers of the transgressive systems tract favoured the establishment of thrombolitic boundstones in protected (back-shoal) environments.


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