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A revised ontogeny of the early Ordovician trilobite Leptoplastides salteri (Callaway, 1877)

Månsson, Kristina LU and Clarkson, Euan N.K. (2018) In Earth and Environmental Science Transactions of the Royal Society of Edinburgh
Abstract

The ontogeny of the pelturine olenid trilobite Leptoplastides salteri (Callaway, 1877) from the Shineton Shales, Shropshire, England, was first described in 1925 by Frank Raw. Since that time, scanning electron microscopy and other new technologies have revealed many more details of structure, of early developmental stages in particular, than were available to Raw. Whereas protaspides are not preserved and the state of preservation is less than perfect for the smallest meraspides, we have established that the latter had an array of delicate, long thoracic and pygidial spines, as well as paired procranidial spines, which disappear by meraspid degree 8. Raw's reconstructions of early meraspides, and his measurements of the early stages in... (More)

The ontogeny of the pelturine olenid trilobite Leptoplastides salteri (Callaway, 1877) from the Shineton Shales, Shropshire, England, was first described in 1925 by Frank Raw. Since that time, scanning electron microscopy and other new technologies have revealed many more details of structure, of early developmental stages in particular, than were available to Raw. Whereas protaspides are not preserved and the state of preservation is less than perfect for the smallest meraspides, we have established that the latter had an array of delicate, long thoracic and pygidial spines, as well as paired procranidial spines, which disappear by meraspid degree 8. Raw's reconstructions of early meraspides, and his measurements of the early stages in development, are here amended in the light of new information. Dorsal spines in the adult are much more highly developed than have been documented in any other olenid. The hypostome is preserved in place in several specimens. Initially conterminant (attached to the doublure), it becomes natant (free) in late meraspid to early holaspid stages of development, with its anterior contour fitting exactly to that of the glabella. The ecology of the widespread Leptoplastides is best known from very extensive sections in South America, which provide a useful basis for comparison. It was well adapted to a range of environments, both oxygenated and dysoxic, and is usually the dominant taxon in the biofacies in which it is found.

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author
organization
publishing date
type
Contribution to journal
publication status
epub
subject
keywords
olenid, Shineton Shales, Shropshire, Tremadoc, Trilobita
in
Earth and Environmental Science Transactions of the Royal Society of Edinburgh
publisher
Royal Society of Edinburgh
external identifiers
  • scopus:85056850639
ISSN
1755-6910
DOI
10.1017/S1755691018000841
language
English
LU publication?
yes
id
29c1af5f-f8fc-4390-952f-3d70eee09916
date added to LUP
2018-11-29 14:52:25
date last changed
2020-01-13 01:14:14
@article{29c1af5f-f8fc-4390-952f-3d70eee09916,
  abstract     = {<p>The ontogeny of the pelturine olenid trilobite Leptoplastides salteri (Callaway, 1877) from the Shineton Shales, Shropshire, England, was first described in 1925 by Frank Raw. Since that time, scanning electron microscopy and other new technologies have revealed many more details of structure, of early developmental stages in particular, than were available to Raw. Whereas protaspides are not preserved and the state of preservation is less than perfect for the smallest meraspides, we have established that the latter had an array of delicate, long thoracic and pygidial spines, as well as paired procranidial spines, which disappear by meraspid degree 8. Raw's reconstructions of early meraspides, and his measurements of the early stages in development, are here amended in the light of new information. Dorsal spines in the adult are much more highly developed than have been documented in any other olenid. The hypostome is preserved in place in several specimens. Initially conterminant (attached to the doublure), it becomes natant (free) in late meraspid to early holaspid stages of development, with its anterior contour fitting exactly to that of the glabella. The ecology of the widespread Leptoplastides is best known from very extensive sections in South America, which provide a useful basis for comparison. It was well adapted to a range of environments, both oxygenated and dysoxic, and is usually the dominant taxon in the biofacies in which it is found.</p>},
  author       = {Månsson, Kristina and Clarkson, Euan N.K.},
  issn         = {1755-6910},
  language     = {eng},
  month        = {11},
  publisher    = {Royal Society of Edinburgh},
  series       = {Earth and Environmental Science Transactions of the Royal Society of Edinburgh},
  title        = {A revised ontogeny of the early Ordovician trilobite Leptoplastides salteri (Callaway, 1877)},
  url          = {http://dx.doi.org/10.1017/S1755691018000841},
  doi          = {10.1017/S1755691018000841},
  year         = {2018},
}