The stapes of gomphodont cynodonts: Insights into the middle ear structure of non-mammaliaform cynodonts
The stapes is known in several non-mammaliaform cynodonts, although it has only been cursorily studied. Here we thoroughly analyze the stapedial anatomy of several basal cynodonts in a phylogenetic framework. Our study shows that the stapedial anatomy is more variable than previously thought. The mo...
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2015
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19326203_v10_n7_p_Gaetano http://hdl.handle.net/20.500.12110/paper_19326203_v10_n7_p_Gaetano |
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paper:paper_19326203_v10_n7_p_Gaetano2023-06-08T16:30:31Z The stapes of gomphodont cynodonts: Insights into the middle ear structure of non-mammaliaform cynodonts Gaetano, Leandro Carlos animal tissue Article auditory system Diademodon tetragonus eardrum Exaeretodon argentinus Gomphodont cynodont Langbergia modisei Laurasiatheria Luangwa drysdalli Massetognathus pascuali Menadon besairei middle ear morphological trait nonhuman phylogeny Scalenodon angustifrons stapes Trirachodon berryi anatomy and histology animal evolution fossil incus skull stapes vertebrate Animals Biological Evolution Ear, Middle Fossils Incus Phylogeny Skull Stapes Tympanic Membrane Vertebrates The stapes is known in several non-mammaliaform cynodonts, although it has only been cursorily studied. Here we thoroughly analyze the stapedial anatomy of several basal cynodonts in a phylogenetic framework. Our study shows that the stapedial anatomy is more variable than previously thought. The morphological variation of the stapes led to the recognition of 11 phylogenetic characters that were included in a total evidence data matrix centered in the analysis of gomphodont cynodonts. Stapes morphology does not provide evidence to suggest a direct connection between the stapes and a postquadrate tympanic membrane (if present) and the hypothesis of a dorsal process as the site of attachment of a small ligament or the stapedial muscle is supported. The re-evaluation of the theories concerning the position of the tympanic membrane in non-mammaliaform cynodonts allowed us to conclude that the hypothetical postquadrate tympanic membrane associated with the squamosal sulcus is at best relictual and most likely non-functional (not connected with the stapes). The sound waves were most likely transmitted to the stapes from a postdentary tympanic membrane through the quadrate. Our analysis results in a better understanding of the auditory system in basal cynodonts and its evolution, highlighting the variability of the stapedial anatomy. Copyright: © 2015 Gaetano, Abdala. Fil:Gaetano, L.C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2015 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19326203_v10_n7_p_Gaetano http://hdl.handle.net/20.500.12110/paper_19326203_v10_n7_p_Gaetano |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
animal tissue Article auditory system Diademodon tetragonus eardrum Exaeretodon argentinus Gomphodont cynodont Langbergia modisei Laurasiatheria Luangwa drysdalli Massetognathus pascuali Menadon besairei middle ear morphological trait nonhuman phylogeny Scalenodon angustifrons stapes Trirachodon berryi anatomy and histology animal evolution fossil incus skull stapes vertebrate Animals Biological Evolution Ear, Middle Fossils Incus Phylogeny Skull Stapes Tympanic Membrane Vertebrates |
| spellingShingle |
animal tissue Article auditory system Diademodon tetragonus eardrum Exaeretodon argentinus Gomphodont cynodont Langbergia modisei Laurasiatheria Luangwa drysdalli Massetognathus pascuali Menadon besairei middle ear morphological trait nonhuman phylogeny Scalenodon angustifrons stapes Trirachodon berryi anatomy and histology animal evolution fossil incus skull stapes vertebrate Animals Biological Evolution Ear, Middle Fossils Incus Phylogeny Skull Stapes Tympanic Membrane Vertebrates Gaetano, Leandro Carlos The stapes of gomphodont cynodonts: Insights into the middle ear structure of non-mammaliaform cynodonts |
| topic_facet |
animal tissue Article auditory system Diademodon tetragonus eardrum Exaeretodon argentinus Gomphodont cynodont Langbergia modisei Laurasiatheria Luangwa drysdalli Massetognathus pascuali Menadon besairei middle ear morphological trait nonhuman phylogeny Scalenodon angustifrons stapes Trirachodon berryi anatomy and histology animal evolution fossil incus skull stapes vertebrate Animals Biological Evolution Ear, Middle Fossils Incus Phylogeny Skull Stapes Tympanic Membrane Vertebrates |
| description |
The stapes is known in several non-mammaliaform cynodonts, although it has only been cursorily studied. Here we thoroughly analyze the stapedial anatomy of several basal cynodonts in a phylogenetic framework. Our study shows that the stapedial anatomy is more variable than previously thought. The morphological variation of the stapes led to the recognition of 11 phylogenetic characters that were included in a total evidence data matrix centered in the analysis of gomphodont cynodonts. Stapes morphology does not provide evidence to suggest a direct connection between the stapes and a postquadrate tympanic membrane (if present) and the hypothesis of a dorsal process as the site of attachment of a small ligament or the stapedial muscle is supported. The re-evaluation of the theories concerning the position of the tympanic membrane in non-mammaliaform cynodonts allowed us to conclude that the hypothetical postquadrate tympanic membrane associated with the squamosal sulcus is at best relictual and most likely non-functional (not connected with the stapes). The sound waves were most likely transmitted to the stapes from a postdentary tympanic membrane through the quadrate. Our analysis results in a better understanding of the auditory system in basal cynodonts and its evolution, highlighting the variability of the stapedial anatomy. Copyright: © 2015 Gaetano, Abdala. |
| author |
Gaetano, Leandro Carlos |
| author_facet |
Gaetano, Leandro Carlos |
| author_sort |
Gaetano, Leandro Carlos |
| title |
The stapes of gomphodont cynodonts: Insights into the middle ear structure of non-mammaliaform cynodonts |
| title_short |
The stapes of gomphodont cynodonts: Insights into the middle ear structure of non-mammaliaform cynodonts |
| title_full |
The stapes of gomphodont cynodonts: Insights into the middle ear structure of non-mammaliaform cynodonts |
| title_fullStr |
The stapes of gomphodont cynodonts: Insights into the middle ear structure of non-mammaliaform cynodonts |
| title_full_unstemmed |
The stapes of gomphodont cynodonts: Insights into the middle ear structure of non-mammaliaform cynodonts |
| title_sort |
stapes of gomphodont cynodonts: insights into the middle ear structure of non-mammaliaform cynodonts |
| publishDate |
2015 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19326203_v10_n7_p_Gaetano http://hdl.handle.net/20.500.12110/paper_19326203_v10_n7_p_Gaetano |
| work_keys_str_mv |
AT gaetanoleandrocarlos thestapesofgomphodontcynodontsinsightsintothemiddleearstructureofnonmammaliaformcynodonts AT gaetanoleandrocarlos stapesofgomphodontcynodontsinsightsintothemiddleearstructureofnonmammaliaformcynodonts |
| _version_ |
1768544013362659328 |