The anatomy of the killer whale middle ear (Orcinus orca)

Nummela, Sirpa; Reuter, Tom; Hemilä, Simo; Holmberg, P.; Paukku, P.

doi:10.1016/s0378-5955(99)00053-2

Cited by 45 publications

(36 citation statements)

References 17 publications

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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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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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“…cetaceans (which are modified to hear underwater) 42 and golden moles (which appear to hear ground vibrations through inertial bone conduction). 43 As Fleischer 44 observed, however, the majority of living mammals fall somewhere on a spectrum ranging between the 'freely mobile' ossicular morphology seen in humans and guinea pigs (Figures 1d and 2a) and the 'microtype' morphology characteristic of bats, shrews and mice ( Figure 2b).…”

Section: Mammalian Middle Earsmentioning

confidence: 99%

Flexibility within the middle ears of vertebrates

Mason

Farr

2012

J. Laryngol. Otol.

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Introduction and aims: Tympanic middle ears have evolved multiple times independently among vertebrates, and share common features. We review flexibility within tympanic middle ears and consider its physiological and clinical implications.Comparative anatomy: The chain of conducting elements is flexible: even the 'single ossicle' ears of most nonmammalian tetrapods are functionally 'double ossicle' ears due to mobile articulations between the stapes and extrastapes; there may also be bending within individual elements.Simple models: Simple models suggest that flexibility will generally reduce the transmission of sound energy through the middle ear, although in certain theoretical situations flexibility within or between conducting elements might improve transmission. The most obvious role of middle-ear flexibility is to protect the inner ear from high-amplitude displacements.Clinical implications: Inter-ossicular joint dysfunction is associated with a number of pathologies in humans. We examine attempts to improve prosthesis design by incorporating flexible components.

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“…The T-P complex, which is suspended through ligaments outside the skull in a peribullar cavity, is surrounded by air filled sinuses, allowing the acoustic isolation from the skull (Reysenbach de Haan, 1957;Fleischer, 1976;Ketten and Wartzok, 1990;Nummela et al, 1999b). While some authors expressed doubts about the functionality of the middle ear (Fraser and Purves, 1954;Reysenbach de Haan, 1957;McCormick et al, 1970;Fleisher, 1978;Ridgway et al, 1997) others presented morphological evidences supporting the active role of the middle ear in sound transmission (Nummela et al, 1999a,b;Hemila et al, 1999Hemila et al, , 2001Ketten, 2000;Morell et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Decalcifying odontocete ears following a routine protocol with RDO®

Degollada

Alonso

Jauniaux

et al. 2009

Journal of Experimental Marine Biology and Ecology

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The study of the organ of Corti is essential to assess the impact of underwater noise on cetaceans. While classical histology techniques (including EDTA decalcification) have been previously considered, the process is time consuming. Independently from the histological technique, one of the challenging steps after extraction and fixation of the samples is to decalcify the bone envelope to access the cochlea without damaging the soft tissues. Here, we propose to use a fast commercial decalcifier (RDO®). 93 ears from 11 different odontocetes species stranded in the Mediterranean, Spanish North Atlantic and North Sea were used to precisely determine the decalcification time. Depending on the tympanic-periotic volume of the species, the decalcification time ranged from several hours to a few days, allowing a subsequently faster observation of the cochlear structures through routine microscope techniques.

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The anatomy of the killer whale middle ear (Orcinus orca)

Cited by 45 publications

References 17 publications

Three-dimensional Magnetic Resonance Imaging of fossils across taxa

Three-dimensional Magnetic Resonance Imaging of fossils across taxa

Flexibility within the middle ears of vertebrates

Decalcifying odontocete ears following a routine protocol with RDO®

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