Prenatal developmental sequence of the skull of minke whales and its implications for the evolution of mysticetes and the teeth‐to‐baleen transition

Baleen whales (Mysticeti) have an extraordinary fossil record documenting the transition from toothed raptorial taxa to modern species that bear baleen plates, keratinous bristles employed in filter‐feeding. Remnants of their toothed ancestry can be found in their ontogeny, as they still develop too...

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Published in:Journal of Anatomy
Main Author: Lanzetti, Agnese
Format: Text
Language:English
Published: John Wiley and Sons Inc. 2019
Subjects:
Online Access:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6742893/
http://www.ncbi.nlm.nih.gov/pubmed/31216066
https://doi.org/10.1111/joa.13029
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spelling ftpubmed:oai:pubmedcentral.nih.gov:6742893 2023-05-15T15:36:11+02:00 Prenatal developmental sequence of the skull of minke whales and its implications for the evolution of mysticetes and the teeth‐to‐baleen transition Lanzetti, Agnese 2019-06-19 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6742893/ http://www.ncbi.nlm.nih.gov/pubmed/31216066 https://doi.org/10.1111/joa.13029 en eng John Wiley and Sons Inc. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6742893/ http://www.ncbi.nlm.nih.gov/pubmed/31216066 http://dx.doi.org/10.1111/joa.13029 © 2019 Anatomical Society J Anat Original Articles Text 2019 ftpubmed https://doi.org/10.1111/joa.13029 2021-10-03T00:20:40Z Baleen whales (Mysticeti) have an extraordinary fossil record documenting the transition from toothed raptorial taxa to modern species that bear baleen plates, keratinous bristles employed in filter‐feeding. Remnants of their toothed ancestry can be found in their ontogeny, as they still develop tooth germs in utero. Understanding the developmental transition from teeth to baleen and the associated skull modifications in prenatal specimens of extant species can enhance our understanding of the evolutionary history of this lineage by using ontogeny as a relative proxy of the evolutionary changes observed in the fossil record. Although at present very little information is available on prenatal development of baleen whales, especially regarding tooth resorption and baleen formation, due to a lack of specimens. Here I present the first detailed description of prenatal specimens of minke whales (Balaenoptera acutorostrata and Balaenoptera bonaerensis), focusing on the skull anatomy and tooth germ development, resorption, and baleen growth. The ontogenetic sequence described consists of 10 specimens of both minke whale species, from the earliest fetal stages to full term. The internal skull anatomy of the specimens was visualized using traditional and iodine‐enhanced computed tomography scanning. These high‐quality data allow detailed description of skull development both qualitatively and quantitatively using three‐dimensional landmark analysis. I report distinctive external anatomical changes and the presence of a denser tissue medial to the tooth germs in specimens from the final portion of gestation, which can be interpreted as the first signs of baleen formation (baleen rudiments). Tooth germs are only completely resorbed just before the eruption of the baleen from the gums, and they are still present for a brief period with baleen rudiments. Skull shape development is characterized by progressive elongation of the rostrum relative to the braincase and by the relative anterior movement of the supraoccipital ... Text Balaenoptera acutorostrata Balaenoptera bonaerensis baleen whales minke whale PubMed Central (PMC) Journal of Anatomy 235 4 725 748
institution Open Polar
collection PubMed Central (PMC)
op_collection_id ftpubmed
language English
topic Original Articles
spellingShingle Original Articles
Lanzetti, Agnese
Prenatal developmental sequence of the skull of minke whales and its implications for the evolution of mysticetes and the teeth‐to‐baleen transition
topic_facet Original Articles
description Baleen whales (Mysticeti) have an extraordinary fossil record documenting the transition from toothed raptorial taxa to modern species that bear baleen plates, keratinous bristles employed in filter‐feeding. Remnants of their toothed ancestry can be found in their ontogeny, as they still develop tooth germs in utero. Understanding the developmental transition from teeth to baleen and the associated skull modifications in prenatal specimens of extant species can enhance our understanding of the evolutionary history of this lineage by using ontogeny as a relative proxy of the evolutionary changes observed in the fossil record. Although at present very little information is available on prenatal development of baleen whales, especially regarding tooth resorption and baleen formation, due to a lack of specimens. Here I present the first detailed description of prenatal specimens of minke whales (Balaenoptera acutorostrata and Balaenoptera bonaerensis), focusing on the skull anatomy and tooth germ development, resorption, and baleen growth. The ontogenetic sequence described consists of 10 specimens of both minke whale species, from the earliest fetal stages to full term. The internal skull anatomy of the specimens was visualized using traditional and iodine‐enhanced computed tomography scanning. These high‐quality data allow detailed description of skull development both qualitatively and quantitatively using three‐dimensional landmark analysis. I report distinctive external anatomical changes and the presence of a denser tissue medial to the tooth germs in specimens from the final portion of gestation, which can be interpreted as the first signs of baleen formation (baleen rudiments). Tooth germs are only completely resorbed just before the eruption of the baleen from the gums, and they are still present for a brief period with baleen rudiments. Skull shape development is characterized by progressive elongation of the rostrum relative to the braincase and by the relative anterior movement of the supraoccipital ...
format Text
author Lanzetti, Agnese
author_facet Lanzetti, Agnese
author_sort Lanzetti, Agnese
title Prenatal developmental sequence of the skull of minke whales and its implications for the evolution of mysticetes and the teeth‐to‐baleen transition
title_short Prenatal developmental sequence of the skull of minke whales and its implications for the evolution of mysticetes and the teeth‐to‐baleen transition
title_full Prenatal developmental sequence of the skull of minke whales and its implications for the evolution of mysticetes and the teeth‐to‐baleen transition
title_fullStr Prenatal developmental sequence of the skull of minke whales and its implications for the evolution of mysticetes and the teeth‐to‐baleen transition
title_full_unstemmed Prenatal developmental sequence of the skull of minke whales and its implications for the evolution of mysticetes and the teeth‐to‐baleen transition
title_sort prenatal developmental sequence of the skull of minke whales and its implications for the evolution of mysticetes and the teeth‐to‐baleen transition
publisher John Wiley and Sons Inc.
publishDate 2019
url http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6742893/
http://www.ncbi.nlm.nih.gov/pubmed/31216066
https://doi.org/10.1111/joa.13029
genre Balaenoptera acutorostrata
Balaenoptera bonaerensis
baleen whales
minke whale
genre_facet Balaenoptera acutorostrata
Balaenoptera bonaerensis
baleen whales
minke whale
op_source J Anat
op_relation http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6742893/
http://www.ncbi.nlm.nih.gov/pubmed/31216066
http://dx.doi.org/10.1111/joa.13029
op_rights © 2019 Anatomical Society
op_doi https://doi.org/10.1111/joa.13029
container_title Journal of Anatomy
container_volume 235
container_issue 4
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