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A Complete Reconstruction of the Hyolithid Skeleton

Marti Mus, Monica; Jeppsson, Lennart LU and Malinky, John M. (2014) In Journal of Paleontology 88(1). p.160-170
Abstract
Hyolithids are a group of Paleozoic lophotrochozoans with a four-pieced skeleton consisting of a conch, an operculum, and a pair of lateral 'spines' named helens. Both the conch and operculum are relatively well known and, to a certain extent, have modern analogues in other lophotrochozoan groups. The helens, on the other hand, are less well known and do not have clear modern analogues. This has hindered the knowledge of the complete morphology of the hyolithid skeleton, as well as other aspects of hyolithid biology, such as the organization of soft parts, and their ability to move. The material studied herein, consisting of disarticulated skeletal elements from the Silurian of Gotland, Sweden, illustrates a complete developmental sequence... (More)
Hyolithids are a group of Paleozoic lophotrochozoans with a four-pieced skeleton consisting of a conch, an operculum, and a pair of lateral 'spines' named helens. Both the conch and operculum are relatively well known and, to a certain extent, have modern analogues in other lophotrochozoan groups. The helens, on the other hand, are less well known and do not have clear modern analogues. This has hindered the knowledge of the complete morphology of the hyolithid skeleton, as well as other aspects of hyolithid biology, such as the organization of soft parts, and their ability to move. The material studied herein, consisting of disarticulated skeletal elements from the Silurian of Gotland, Sweden, illustrates a complete developmental sequence of a hyolithid species and includes the first complete, three-dimensionally preserved helens. Our material confirms that helens were massive skeletal elements, whose growth started proximally with the deposition of a central, coherent lamella. Further shell accretion took place around this lamella, but followed a particular accretion pattern probably constrained by the presence of marginal muscle attachment sites on the proximal-most portion of the helens. These muscle attachment sites were ideally located to allow a wide range of movements for the helens, suggesting that hyolithids may have been relatively mobile organisms. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Paleontology
volume
88
issue
1
pages
160 - 170
publisher
Paleontological Society
external identifiers
  • wos:000329946800009
  • scopus:84892933591
ISSN
0022-3360
DOI
10.1666/13-038
language
English
LU publication?
yes
id
204fa5b5-fd1d-49b0-926a-931a18998c97 (old id 4319136)
date added to LUP
2014-02-25 14:50:22
date last changed
2017-11-05 03:56:06
@article{204fa5b5-fd1d-49b0-926a-931a18998c97,
  abstract     = {Hyolithids are a group of Paleozoic lophotrochozoans with a four-pieced skeleton consisting of a conch, an operculum, and a pair of lateral 'spines' named helens. Both the conch and operculum are relatively well known and, to a certain extent, have modern analogues in other lophotrochozoan groups. The helens, on the other hand, are less well known and do not have clear modern analogues. This has hindered the knowledge of the complete morphology of the hyolithid skeleton, as well as other aspects of hyolithid biology, such as the organization of soft parts, and their ability to move. The material studied herein, consisting of disarticulated skeletal elements from the Silurian of Gotland, Sweden, illustrates a complete developmental sequence of a hyolithid species and includes the first complete, three-dimensionally preserved helens. Our material confirms that helens were massive skeletal elements, whose growth started proximally with the deposition of a central, coherent lamella. Further shell accretion took place around this lamella, but followed a particular accretion pattern probably constrained by the presence of marginal muscle attachment sites on the proximal-most portion of the helens. These muscle attachment sites were ideally located to allow a wide range of movements for the helens, suggesting that hyolithids may have been relatively mobile organisms.},
  author       = {Marti Mus, Monica and Jeppsson, Lennart and Malinky, John M.},
  issn         = {0022-3360},
  language     = {eng},
  number       = {1},
  pages        = {160--170},
  publisher    = {Paleontological Society},
  series       = {Journal of Paleontology},
  title        = {A Complete Reconstruction of the Hyolithid Skeleton},
  url          = {http://dx.doi.org/10.1666/13-038},
  volume       = {88},
  year         = {2014},
}