Three-Dimensional Reconstructions of the Dolphin EAR

Ketten, Darlene R.; Wartzok, Douglas

doi:10.1007/978-1-4899-0858-2_6

Cited by 85 publications

(137 citation statements)

References 31 publications

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“…In our study, the shape of the melon is, for the first time, visualised di- Computed tomography scans and necropsy sections allowed to determine precisely some measurements of the ears. We confirmed previous data (Ketten & Wartzok, 1990), and we highlighted a peculiar fact: the petrotympanic bones of the harbour porpoise are of the same size as the petrotympanic bones of the common dolphin.…”

Section: The Complementary Use Of Mri Ct Scans and Anatomical Sectsupporting

confidence: 91%

“…However, CT scans, which use Xrays attenuation, are more efficient to observe hard tissues such as bones. It is for this reason that, like Ketten and Wartzok (1990), we used CT scanning in order to compare the head bones of the common dolphin and the harbour porpoise, and in particular the mandibles and the middle/inner ear bones, major head bones belonging to the echolocation systems in odontocetes.…”

Section: The Complementary Use Of Mri Ct Scans and Anatomical Sectmentioning

confidence: 99%

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Comparative anatomical study of sound production and reception systems in the common dolphin (Delphinus delphis) and the harbour porpoise (Phocoena phocoena) heads

Arribart

Tavernier

Richaudeau

et al. 2017

Anat Histol Embryol

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SummaryMagnetic resonance imaging (MRI) and computed tomography (CT) scans were used to analyse, respectively, the soft tissues and the bones of the heads of four common dolphins and three harbour porpoises. This imaging study was completed by an examination of anatomical sections performed on two odontocete heads (a subadult common dolphin and a subadult harbour porpoise). The three complementary approaches allowed to illustrate anatomical differences in the echolocation systems of the common dolphin and the harbour porpoise. We captured images confirming strong differences of symmetry of the melon and of its connexions to the MLDB (Monkeys Lips/ Dorsal Bursae) between the common dolphin and the harbour porpoise. The melon of the common dolphin is asymmetrically directly connected to the right bursae cantantes at its right side, whereas the melon of the harbour porpoise is symmetrical, and separated from the two bursae cantantes by a set of connective tissues. Another striking difference comes from the bursae cantantes themselves, less deeply located in the head of the common dolphin than in the harbour porpoise.

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Section: The Complementary Use Of Mri Ct Scans and Anatomical Sectsupporting

confidence: 91%

Section: The Complementary Use Of Mri Ct Scans and Anatomical Sectmentioning

confidence: 99%

Comparative anatomical study of sound production and reception systems in the common dolphin (Delphinus delphis) and the harbour porpoise (Phocoena phocoena) heads

Arribart

Tavernier

Richaudeau

et al. 2017

Anat Histol Embryol

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“…In species with ears specialized for low frequency hearing, the basilar membrane is generally wider and thinner, with the outer spiral laminae thinner and if present, located only in the basal region of the cochlea (Echteler et al, 1994). Measurements of basal and apical stiffness of the basilar membrane, which can be approximated by the ratio of thickness to width, appear to predict the upper and lower frequency limits equally well for both generalists and specialist ears (Ketten and Wartzok, 1990), and comparative anatomical studies of cetacean and terrestrial mammalian ears demonstrate significant structural variants unique to cetacean ears (Ketten, 1992).…”

Section: Anatomical Modeling For Marine Mammal Hearingmentioning

confidence: 95%

“…Functional studies of the inner ear focus on resonance characteristics of the basilar membrane. Models have been developed to predict the frequency range of hearing for cetaceans in particular based on basilar membrane measurements (Ketten and Wartzok, 1990). Position-frequency maps and basilar membrane elasticity measurements from humans as well as other mammal and bird species were used by Greenwood to derive formulae for predicting frequency maxima, minima, and distribution along the length of the basilar membrane for land mammals (Greenwood, 1961(Greenwood, , 1962(Greenwood, , 1990.…”

Section: Anatomical Modeling For Marine Mammal Hearingmentioning

confidence: 99%

Anatomical predictions of hearing in the North Atlantic right whale

Parks

Ketten

O’Malley

et al. 2007

The Anatomical Record

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Some knowledge of the hearing abilities of right whales is important for understanding their acoustic communication system and possible impacts of anthropogenic noise. Traditional behavioral or physiological techniques to test hearing are not feasible with right whales. Previous research on the hearing of marine mammals has shown that functional models are reliable estimators of hearing sensitivity in marine species. Fundamental to these models is a comprehensive analysis of inner ear anatomy. Morphometric analyses of 18 inner ears from 13 stranded North Atlantic right whales (Eubalaena glacialis) were used for development of a preliminary model of the frequency range of hearing. Computerized tomography was used to create two-dimensional (2D) and 3D images of the cochlea. Four ears were decalcified and sectioned for histologic measurements of the basilar membrane. Basilar membrane length averaged 55.7 mm (range, 50.5 mm-61.7 mm). The ganglion cell density/mm averaged 1,842 ganglion cells/mm. The thickness/width measurements of the basilar membrane from slides resulted in an estimated hearing range of 10 Hz-22 kHz based on established marine mammal models. Additional measurements from more specimens will be necessary to develop a more robust model of the right whale hearing range. Anat Rec, 290:734-744, 2007. 2007 Wiley-Liss, Inc.

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“…Petrosals obtained from contemporary animals (e.g. Ketten and Wartzok, 1990;Nummela et al, 1999) have successfully been imaged by CT, as have fossil cetacean petrosals (Spoor et al, 2002) and entire fossil cetacean skulls (at resolutions not suitable for petrosal investigations, cf. Marino et al, 2003).…”

Section: Fossil Ear Bonesmentioning

confidence: 99%

Three-dimensional Magnetic Resonance Imaging of fossils across taxa

Mietchen

Aberhan²,

Manz

et al. 2008

Biogeosciences

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Abstract. The frequency of life forms in the fossil record is largely determined by the extent to which they were mineralised at the time of their death. In addition to mineral structures, many fossils nonetheless contain detectable amounts of residual water or organic molecules, the analysis of which has become an integral part of current palaeontological research. The methods available for this sort of investigations, though, typically require dissolution or ionisation of the fossil sample or parts thereof, which is an issue with rare taxa and outstanding materials like pathological or type specimens. In such cases, non-destructive techniques could provide a valuable methodological alternative. While Computed Tomography has long been used to study palaeontological specimens, a number of complementary approaches have recently gained ground. These include Magnetic Resonance Imaging (MRI) which had previously been employed to obtain three-dimensional images of pathological belemnites non-invasively on the basis of intrinsic contrast. The present study was undertaken to investigate whether 1 H MRI can likewise provide anatomical information about nonpathological belemnites and specimens of other fossil taxa. To this end, three-dimensional MR image series were acquired from intact non-pathological invertebrate, vertebrate and plant fossils. At routine voxel resolutions in the range of several dozens to some hundreds of micrometers, these images reveal a host of anatomical details and thus highlight the potential of MR techniques to effectively complement existing methodological approaches for palaeontological investigations in a wide range of taxa. As for the origin of the MR signal, relaxation and diffusion measurements as well as 1 H and 13 C MR spectra acquired from a belemnite suggest intracrystalline water or hydroxyl groups, rather than organic residues.

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Three-Dimensional Reconstructions of the Dolphin EAR

Cited by 85 publications

References 31 publications

Comparative anatomical study of sound production and reception systems in the common dolphin (Delphinus delphis) and the harbour porpoise (Phocoena phocoena) heads

Comparative anatomical study of sound production and reception systems in the common dolphin (Delphinus delphis) and the harbour porpoise (Phocoena phocoena) heads

Anatomical predictions of hearing in the North Atlantic right whale

Three-dimensional Magnetic Resonance Imaging of fossils across taxa

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