Project 833: E. G. Ekdale. 2013. Comparative Anatomy of the Bony Labyrinth (Inner Ear) of Placental Mammals. PLOS ONE. 8 (6):e66624.
Specimen: Dasypus novemcinctus (TMM/M:1885)

Abstract

Background

Variation is a naturally occurring phenomenon that is observable at all levels of morphology, from anatomical variations of DNA molecules to gross variations between whole organisms. The structure of the otic region is no exception. The present paper documents the broad morphological diversity exhibited by the inner ear region of placental mammals using digital endocasts constructed from high-resolution X-ray computed tomography (CT). Descriptions cover the major placental clades, and linear, angular, and volumetric dimensions are reported.

Principal Findings

The size of the labyrinth is correlated to the overall body mass of individuals, such that large bodied mammals have absolutely larger labyrinths. The ratio between the average arc radius of curvature of the three semicircular canals and body mass of aquatic species is substantially lower than the ratios of related terrestrial taxa, and the volume percentage of the vestibular apparatus of aquatic mammals tends to be less than that calculated for terrestrial species. Aspects of the bony labyrinth are phylogenetically informative, including vestibular reduction in Cetacea, a tall cochlear spiral in caviomorph rodents, a low position of the plane of the lateral semicircular canal compared to the posterior canal in Cetacea and Carnivora, and a low cochlear aspect ratio in Primatomorpha.

Significance

The morphological descriptions that are presented add a broad baseline of anatomy of the inner ear across many placental mammal clades, for many of which the structure of the bony labyrinth is largely unknown. The data included here complement the growing body of literature on the physiological and phylogenetic significance of bony labyrinth structures in mammals, and they serve as a source of data for future studies on the evolution and function of the vertebrate ear.



Read the article »

Project DOI: 10.7934/P833, http://dx.doi.org/10.7934/P833
This project containsMatrices
  • 214 Media
  • 1 Matrix
  • 2 Documents
  • 36 Taxa
  • 37 Specimens
  • 6 Characters
Total size of project's media files: 58 MB

Download Project SDD File
Total scored cells: 216
Total media associated with cells: 291
Total labels associated with cell media: 219
Characters
Total characters: 6
Total characters with associated media: 0
Total characters with media with labels: 0
Total character states: 16
Total character states with associated media: 16
Total character states with media with labels:14
Total unordered/ordered characters:6/0
Currently Viewing:
MorphoBank Project 833


    Members

    member name taxa specimens media media
    notes
    chars character
    comms
       
    notes  media
    labels
    cell scorings
    (scored, NPA, "-")
    cell
    comms
        
    notes  medialabels
    rules
    Eric Ekdale
    Project Administrator
    Last logged in 06/23/13
    36372142086061610216
    (216, 0, 0)
    01442912190


    Taxonomic Overview for Matrix 'M1905' (36 Taxa)

    taxon unscored
    cells
    scored
    cells
    no cell
    support
    NPA
    cells
    "-" cellscell images labels on
    cell images
    member
    access
    [1] Didelphis virginiana
    Last Modified in 12/05/13
    06000971
    [2] † Kulbeckia kulbecke
    Last Modified in 12/05/13
    06000861
    [3] † Ukhaatherium nessovi
    Last Modified in 12/05/13
    06000861
    [4] † Zalambdalestes lechei
    Last Modified in 12/05/13
    06000861
    [5] † Zhelestid
    Last Modified in 12/05/13
    06000861
    [6] Chrysochloris sp.
    Last Modified in 12/05/13
    06000861
    [7] † Elephantimorpha
    Last Modified in 12/05/13
    06000861
    [8] Hemicentetes semispinosum
    Last Modified in 12/05/13
    06000861
    [9] Macroscelides proboscideus
    Last Modified in 12/05/13
    06000861
    [10] Orycteropus afer
    Last Modified in 12/05/13
    06000861
    [11] Procavia capensis
    Last Modified in 12/05/13
    06000861
    [12] Trichechus manatus
    Last Modified in 12/05/13
    06000861
    [13] Dasypus novemcinctus
    Last Modified in 12/05/13
    06000861
    [14] Atelerix albiventris
    Last Modified in 12/05/13
    06000861
    [15] † Balaenopteridae
    Last Modified in 12/05/13
    06000971
    [16] † Bathygenys reevesi
    Last Modified in 12/05/13
    06000861
    [17] Canis familiaris
    Last Modified in 12/05/13
    06000861
    [18] Equus caballus
    Last Modified in 12/05/13
    06000861
    [19] Eumetopias jubatus
    Last Modified in 12/05/13
    06000861
    [20] Felis catus
    Last Modified in 12/05/13
    06000861
    [21] Manis tricuspis
    Last Modified in 12/05/13
    06000861
    [22] Nycteris grandis
    Last Modified in 12/05/13
    06000861
    [23] Pteropus lylei
    Last Modified in 12/05/13
    06000861
    [24] Rhinolophus ferrumequinum
    Last Modified in 12/05/13
    06000861
    [25] Sorex monticolus
    Last Modified in 12/05/13
    06000971
    [26] Sus scrofa
    Last Modified in 12/05/13
    06000861
    [27] Tadarida brasiliensis
    Last Modified in 12/05/13
    06000861
    [28] Tursiops truncatus
    Last Modified in 12/05/13
    06000861
    [29] Cavia porcellus
    Last Modified in 12/05/13
    06000861
    [30] Cynocephalus volans
    Last Modified in 12/05/13
    06000861
    [31] Homo sapiens
    Last Modified in 12/05/13
    06000861
    [32] Lepus californicus
    Last Modified in 12/05/13
    06000861
    [33] Macaca mulatta
    Last Modified in 12/05/13
    06000861
    [34] Mus musculus
    Last Modified in 12/05/13
    06000861
    [35] Sylvilagus floridanus
    Last Modified in 12/05/13
    06000861
    [36] Tupaia glis
    Last Modified in 12/05/13
    06000861


    Project views

    type number of views Individual items viewed (where applicable)
    Total project views109544
    Project overview4086
    Matrix views2019Matrix landing page (1795 views); Discrete Matrix (224 views);
    Media views65431Media search (4727 views); M151280 (424 views); M151334 (426 views); M151284 (448 views); M151328 (441 views); M151330 (416 views); M151372 (413 views); M151362 (371 views); M151363 (422 views); M151295 (453 views); M151323 (394 views); M151281 (406 views); M151451 (170 views); M151446 (215 views); M151369 (434 views); M151618 (246 views); M151368 (399 views); M151329 (432 views); M151356 (403 views); M151374 (471 views); M151365 (475 views); M151285 (405 views); M151354 (343 views); M151312 (384 views); M151359 (438 views); M151301 (442 views); M151311 (429 views); M151320 (373 views); M151396 (384 views); M151293 (409 views); M151383 (439 views); M151380 (408 views); M151408 (173 views); M151333 (428 views); M151357 (396 views); M151367 (349 views); M151303 (348 views); M151459 (130 views); M151491 (159 views); M151370 (402 views); M151386 (413 views); M151472 (162 views); M151353 (405 views); M151385 (383 views); M151390 (435 views); M151299 (415 views); M151437 (148 views); M151375 (397 views); M151283 (530 views); M151393 (403 views); M151307 (414 views); M151468 (147 views); M151316 (418 views); M151436 (130 views); M151401 (212 views); M151484 (190 views); M151443 (164 views); M151378 (434 views); M151428 (175 views); M151457 (140 views); M151441 (159 views); M151394 (446 views); M151317 (383 views); M151387 (412 views); M151382 (430 views); M151489 (188 views); M151366 (380 views); M151306 (373 views); M151454 (168 views); M151282 (525 views); M151298 (404 views); M151326 (435 views); M151361 (397 views); M151325 (403 views); M151324 (465 views); M151371 (418 views); M151360 (373 views); M151617 (273 views); M151331 (404 views); M151391 (354 views); M151381 (408 views); M151300 (372 views); M151377 (343 views); M151297 (507 views); M151310 (376 views); M151314 (435 views); M151632 (193 views); M151342 (388 views); M151389 (417 views); M151628 (161 views); M151373 (428 views); M151421 (172 views); M151442 (191 views); M151341 (400 views); M151395 (434 views); M151469 (177 views); M151304 (467 views); M151379 (400 views); M151313 (403 views); M151322 (428 views); M151327 (365 views); M151343 (404 views); M151345 (357 views); M151358 (407 views); M151318 (429 views); M151315 (421 views); M151321 (410 views); M151405 (148 views); M151364 (433 views); M151388 (382 views); M151309 (439 views); M151440 (134 views); M151344 (356 views); M151296 (396 views); M151418 (221 views); M151458 (213 views); M151352 (421 views); M151466 (202 views); M151319 (398 views); M151585 (156 views); M151586 (169 views); M151587 (187 views); M151588 (174 views); M151589 (129 views); M151590 (149 views); M151616 (216 views); M151619 (167 views); M151620 (149 views); M151621 (176 views); M151629 (172 views); M151630 (181 views); M151631 (152 views); M151633 (202 views); M151634 (191 views); M151635 (161 views); M151636 (164 views); M151637 (165 views); M151638 (143 views); M151639 (205 views); M151376 (400 views); M151474 (168 views); M151305 (433 views); M151384 (434 views); M151302 (391 views); M151397 (363 views); M151355 (424 views); M151286 (367 views); M151294 (433 views); M151332 (380 views); M151392 (415 views); M151308 (462 views); M151479 (224 views); M151414 (153 views); M151465 (131 views); M151400 (161 views); M151462 (161 views); M151470 (188 views); M151420 (176 views); M151430 (158 views); M151402 (156 views); M151485 (181 views); M151447 (144 views); M151435 (165 views); M151398 (195 views); M151407 (169 views); M151492 (184 views); M151449 (131 views); M151488 (161 views); M151399 (179 views); M151452 (169 views); M151471 (152 views); M151406 (206 views); M151413 (156 views); M151412 (160 views); M151429 (165 views); M151403 (172 views); M151404 (163 views); M151409 (175 views); M151410 (176 views); M151411 (229 views); M151415 (155 views); M151416 (163 views); M151417 (150 views); M151419 (177 views); M151431 (130 views); M151432 (154 views); M151433 (186 views); M151434 (126 views); M151438 (164 views); M151439 (161 views); M151444 (159 views); M151445 (182 views); M151448 (168 views); M151450 (200 views); M151453 (151 views); M151455 (167 views); M151456 (158 views); M151460 (180 views); M151461 (159 views); M151463 (149 views); M151464 (140 views); M151467 (259 views); M151473 (166 views); M151475 (164 views); M151476 (158 views); M151477 (164 views); M151478 (175 views); M151480 (185 views); M151481 (160 views); M151482 (151 views); M151483 (176 views); M151486 (151 views); M151487 (203 views); M151490 (161 views); M151493 (195 views);
    Bibliography2124
    Documents list1679
    Specimen list22736
    Taxon list11469




    Project downloads

    type number of downloads Individual items downloaded (where applicable)
    Total downloads from project271
    Media downloads11M151280 (5 downloads); M151295 (1 download); M151369 (1 download); M151618 (1 download); M151374 (1 download); M151362 (1 download); M151304 (1 download);
    Project downloads227
    Matrix downloads22Discrete Matrix (22 downloads);
    Document downloads11Continuous Character Matrix (6 downloads); Combined Discrete and Continuous Character Matrix (5 downloads);