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Element association and morphology in some middle Ordovician platform-equipped conodonts

Löfgren, Anita LU and Zhang, JH (2003) In Journal of Paleontology 77(4). p.721-737
Abstract
Conodont elements other than those with platform ledges along the processes have often been unrecognized or disregarded in reconstructions and phylogenetic discussions of Ordovician "platform conodont genera." The platform elements are larger than the other element types and often exhibit more rapid evolutionary changes in morphology. Nevertheless, to understand the evolution of, and relationships between and among "platform genera," it is necessary to also consider the associated ramiform and geniculate elements. Thus, on the basis of large collections, together comprising 10,800 elements from Sweden and southern China, all element types of Lenodus antivariabilis (An, 1981), L. variabilis (Sergeeva. 1963), Yangtzeplacognathus crassus... (More)
Conodont elements other than those with platform ledges along the processes have often been unrecognized or disregarded in reconstructions and phylogenetic discussions of Ordovician "platform conodont genera." The platform elements are larger than the other element types and often exhibit more rapid evolutionary changes in morphology. Nevertheless, to understand the evolution of, and relationships between and among "platform genera," it is necessary to also consider the associated ramiform and geniculate elements. Thus, on the basis of large collections, together comprising 10,800 elements from Sweden and southern China, all element types of Lenodus antivariabilis (An, 1981), L. variabilis (Sergeeva. 1963), Yangtzeplacognathus crassus (Chen and Zhang, 1993) and Eoplacognathus pseudoplanus (Viira, 1974) are described and discussed. All these species had seven morphologically distinct element types, and probably seventeen individual elements in each apparatus. Ancestors and descendants of these species are discussed more briefly and it is concluded that the ramiform and geniculate elements also are characteristic within each lineage. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Paleontology
volume
77
issue
4
pages
721 - 737
publisher
Paleontological Society
external identifiers
  • wos:000184354900009
  • scopus:0042206631
ISSN
0022-3360
DOI
10.1666/0022-3360(2003)077<0721:EAAMIS>2.0.CO;2
language
English
LU publication?
yes
id
cfc10d65-0e8f-4e18-a46d-266116f8c514 (old id 305221)
date added to LUP
2007-09-17 15:19:13
date last changed
2018-01-07 08:59:44
@article{cfc10d65-0e8f-4e18-a46d-266116f8c514,
  abstract     = {Conodont elements other than those with platform ledges along the processes have often been unrecognized or disregarded in reconstructions and phylogenetic discussions of Ordovician "platform conodont genera." The platform elements are larger than the other element types and often exhibit more rapid evolutionary changes in morphology. Nevertheless, to understand the evolution of, and relationships between and among "platform genera," it is necessary to also consider the associated ramiform and geniculate elements. Thus, on the basis of large collections, together comprising 10,800 elements from Sweden and southern China, all element types of Lenodus antivariabilis (An, 1981), L. variabilis (Sergeeva. 1963), Yangtzeplacognathus crassus (Chen and Zhang, 1993) and Eoplacognathus pseudoplanus (Viira, 1974) are described and discussed. All these species had seven morphologically distinct element types, and probably seventeen individual elements in each apparatus. Ancestors and descendants of these species are discussed more briefly and it is concluded that the ramiform and geniculate elements also are characteristic within each lineage.},
  author       = {Löfgren, Anita and Zhang, JH},
  issn         = {0022-3360},
  language     = {eng},
  number       = {4},
  pages        = {721--737},
  publisher    = {Paleontological Society},
  series       = {Journal of Paleontology},
  title        = {Element association and morphology in some middle Ordovician platform-equipped conodonts},
  url          = {http://dx.doi.org/10.1666/0022-3360(2003)077<0721:EAAMIS>2.0.CO;2},
  volume       = {77},
  year         = {2003},
}