Skeletal elements of the penguin eye and their functional and phylogenetic implications (Aves: Sphenisciformes: Spheniscidae)
Abstract Scleral ossicles and other bony elements are present in the eyes of many vertebrates, including birds. In this study, the skeletal elements present in the penguin eye and orbit were imaged using macro photographs and micro‐computed tomography (micro‐CT), to help elucidate their function and...
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crwiley:10.1002/jmor.21354 2024-06-02T08:13:35+00:00 Skeletal elements of the penguin eye and their functional and phylogenetic implications (Aves: Sphenisciformes: Spheniscidae) Hadden, Peter W. Gerneke, Dane A. McGhee, Charles N. J. Zhang, Jie 2021 http://dx.doi.org/10.1002/jmor.21354 https://onlinelibrary.wiley.com/doi/pdf/10.1002/jmor.21354 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/jmor.21354 en eng Wiley http://creativecommons.org/licenses/by/4.0/ Journal of Morphology volume 282, issue 6, page 874-886 ISSN 0362-2525 1097-4687 journal-article 2021 crwiley https://doi.org/10.1002/jmor.21354 2024-05-03T10:54:56Z Abstract Scleral ossicles and other bony elements are present in the eyes of many vertebrates, including birds. In this study, the skeletal elements present in the penguin eye and orbit were imaged using macro photographs and micro‐computed tomography (micro‐CT), to help elucidate their function and significance. A total of 36 scleral rings and three whole skulls were imaged. King ( Aptenodytes patagonicus ), Fiordland crested ( Eudyptes pachyrhynchus ), Snares crested ( Eudyptes robustus ), royal ( Eudyptes schlegeli ) and yellow‐eyed ( Megadyptes antipodes ) penguins had between 12 and 14 elements in their scleral ring while the gentoo ( Pygoscelis papua ) had 14 and 17; little penguins ( Eudyptula sp.) consistently had between 10 and 12 elements. All had at least two elements that overlapped, usually totally, each neighbour, and two that were overlapped by each neighbour. The interior structure of all ossicles revealed a lattice‐like arrangement of struts typical of cancellous bone, the whole being surrounded by thick cortical bone. The scleral ring of a 10 week gentoo chick was not completely ossified but rather had multiple small holes within it on micro‐CT. A large os opticus was present in one king penguin but in another bird of the same age and gender there was no such bone. Much smaller accessory bones were found in the posterior pole of one Snares crested and one little penguin. We conclude that the penguin scleral ring not only maintains the shape of the eye but also provides protection and a site of insertion for rectus muscles. However, the extreme variability in the os opticus suggests that it is not essential to normal function. Article in Journal/Newspaper Pygoscelis papua Wiley Online Library Journal of Morphology 282 6 874 886 |
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Open Polar |
collection |
Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract Scleral ossicles and other bony elements are present in the eyes of many vertebrates, including birds. In this study, the skeletal elements present in the penguin eye and orbit were imaged using macro photographs and micro‐computed tomography (micro‐CT), to help elucidate their function and significance. A total of 36 scleral rings and three whole skulls were imaged. King ( Aptenodytes patagonicus ), Fiordland crested ( Eudyptes pachyrhynchus ), Snares crested ( Eudyptes robustus ), royal ( Eudyptes schlegeli ) and yellow‐eyed ( Megadyptes antipodes ) penguins had between 12 and 14 elements in their scleral ring while the gentoo ( Pygoscelis papua ) had 14 and 17; little penguins ( Eudyptula sp.) consistently had between 10 and 12 elements. All had at least two elements that overlapped, usually totally, each neighbour, and two that were overlapped by each neighbour. The interior structure of all ossicles revealed a lattice‐like arrangement of struts typical of cancellous bone, the whole being surrounded by thick cortical bone. The scleral ring of a 10 week gentoo chick was not completely ossified but rather had multiple small holes within it on micro‐CT. A large os opticus was present in one king penguin but in another bird of the same age and gender there was no such bone. Much smaller accessory bones were found in the posterior pole of one Snares crested and one little penguin. We conclude that the penguin scleral ring not only maintains the shape of the eye but also provides protection and a site of insertion for rectus muscles. However, the extreme variability in the os opticus suggests that it is not essential to normal function. |
format |
Article in Journal/Newspaper |
author |
Hadden, Peter W. Gerneke, Dane A. McGhee, Charles N. J. Zhang, Jie |
spellingShingle |
Hadden, Peter W. Gerneke, Dane A. McGhee, Charles N. J. Zhang, Jie Skeletal elements of the penguin eye and their functional and phylogenetic implications (Aves: Sphenisciformes: Spheniscidae) |
author_facet |
Hadden, Peter W. Gerneke, Dane A. McGhee, Charles N. J. Zhang, Jie |
author_sort |
Hadden, Peter W. |
title |
Skeletal elements of the penguin eye and their functional and phylogenetic implications (Aves: Sphenisciformes: Spheniscidae) |
title_short |
Skeletal elements of the penguin eye and their functional and phylogenetic implications (Aves: Sphenisciformes: Spheniscidae) |
title_full |
Skeletal elements of the penguin eye and their functional and phylogenetic implications (Aves: Sphenisciformes: Spheniscidae) |
title_fullStr |
Skeletal elements of the penguin eye and their functional and phylogenetic implications (Aves: Sphenisciformes: Spheniscidae) |
title_full_unstemmed |
Skeletal elements of the penguin eye and their functional and phylogenetic implications (Aves: Sphenisciformes: Spheniscidae) |
title_sort |
skeletal elements of the penguin eye and their functional and phylogenetic implications (aves: sphenisciformes: spheniscidae) |
publisher |
Wiley |
publishDate |
2021 |
url |
http://dx.doi.org/10.1002/jmor.21354 https://onlinelibrary.wiley.com/doi/pdf/10.1002/jmor.21354 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/jmor.21354 |
genre |
Pygoscelis papua |
genre_facet |
Pygoscelis papua |
op_source |
Journal of Morphology volume 282, issue 6, page 874-886 ISSN 0362-2525 1097-4687 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1002/jmor.21354 |
container_title |
Journal of Morphology |
container_volume |
282 |
container_issue |
6 |
container_start_page |
874 |
op_container_end_page |
886 |
_version_ |
1800737140921860096 |