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Re-evaluation of the conodont Iapetognathus and implications for the base of the Ordovician System GSSP

Terfelt, Fredrik LU ; Bagnoli, Gabriella and Stouge, Svend (2011) In Lethaia 45(2). p.227-237
Abstract
In 2000, the International Union of Geological Sciences (IUGS) ratified the decision

from the International Working Group on the Cambrian–Ordovician Boundary (COBWG)

to place the Global boundary Stratotype Section and Point (GSSP) for the base of

the Ordovician System in the Green Point section, Newfoundland, Canada, at a point

coinciding with the first appearance of the conodont Iapetognathus fluctivagus. However,

a restudy of the conodont successions from Green Point shows that this species is not

present at the boundary interval, and as a consequence the section does not fulfil the biostratigraphical

requirements of a GSSP. The GSSP horizon as now defined is based on... (More)
In 2000, the International Union of Geological Sciences (IUGS) ratified the decision

from the International Working Group on the Cambrian–Ordovician Boundary (COBWG)

to place the Global boundary Stratotype Section and Point (GSSP) for the base of

the Ordovician System in the Green Point section, Newfoundland, Canada, at a point

coinciding with the first appearance of the conodont Iapetognathus fluctivagus. However,

a restudy of the conodont successions from Green Point shows that this species is not

present at the boundary interval, and as a consequence the section does not fulfil the biostratigraphical

requirements of a GSSP. The GSSP horizon as now defined is based on a

level part-way through the range of I. preaengensis – a species with lower first appearance

datum (FAD). The true FAD of I. fluctivagus is above the FAD of planktonic graptolites

and well above the FAD of I. preaengensis. As a consequence of these problems, a restudy

of the GSSP section and the other sections in the Cow Head Group is necessary. A redefinition

of the GSSP horizon is suggested. The following four alternative horizons have

potential as new horizons for the GSSP level: the FAD of Cordylodus intermedius; the

FAD of Cordylodus andresi; the FAD of Eoconodontus notchpeakensis; and the FAD of the

agnostoid Lotagnostus americanus. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
global boundary stratotype section point, conodont, boundary, cambrian, Iapetognathus, ordovician
in
Lethaia
volume
45
issue
2
pages
227 - 237
publisher
Taylor & Francis
external identifiers
  • scopus:84858217135
ISSN
0024-1164
DOI
10.1111/j.1502-3931.2011.00275.x
language
English
LU publication?
yes
id
7faedc37-143f-4d0b-bc8c-b874178ee408 (old id 4253225)
date added to LUP
2014-01-24 15:44:57
date last changed
2017-11-19 03:53:22
@article{7faedc37-143f-4d0b-bc8c-b874178ee408,
  abstract     = {In 2000, the International Union of Geological Sciences (IUGS) ratified the decision<br/><br>
from the International Working Group on the Cambrian–Ordovician Boundary (COBWG)<br/><br>
to place the Global boundary Stratotype Section and Point (GSSP) for the base of<br/><br>
the Ordovician System in the Green Point section, Newfoundland, Canada, at a point<br/><br>
coinciding with the first appearance of the conodont Iapetognathus fluctivagus. However,<br/><br>
a restudy of the conodont successions from Green Point shows that this species is not<br/><br>
present at the boundary interval, and as a consequence the section does not fulfil the biostratigraphical<br/><br>
requirements of a GSSP. The GSSP horizon as now defined is based on a<br/><br>
level part-way through the range of I. preaengensis – a species with lower first appearance<br/><br>
datum (FAD). The true FAD of I. fluctivagus is above the FAD of planktonic graptolites<br/><br>
and well above the FAD of I. preaengensis. As a consequence of these problems, a restudy<br/><br>
of the GSSP section and the other sections in the Cow Head Group is necessary. A redefinition<br/><br>
of the GSSP horizon is suggested. The following four alternative horizons have<br/><br>
potential as new horizons for the GSSP level: the FAD of Cordylodus intermedius; the<br/><br>
FAD of Cordylodus andresi; the FAD of Eoconodontus notchpeakensis; and the FAD of the<br/><br>
agnostoid Lotagnostus americanus.},
  author       = {Terfelt, Fredrik and Bagnoli, Gabriella and Stouge, Svend},
  issn         = {0024-1164},
  keyword      = {global boundary stratotype section point,conodont,boundary,cambrian,Iapetognathus,ordovician},
  language     = {eng},
  number       = {2},
  pages        = {227--237},
  publisher    = {Taylor & Francis},
  series       = {Lethaia},
  title        = {Re-evaluation of the conodont Iapetognathus and implications for the base of the Ordovician System GSSP},
  url          = {http://dx.doi.org/10.1111/j.1502-3931.2011.00275.x},
  volume       = {45},
  year         = {2011},
}