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 views117031
    Project overview4067
    Matrix views2031Matrix landing page (1806 views); Discrete Matrix (225 views);
    Media views71701Media search (4859 views); M151280 (454 views); M151334 (459 views); M151284 (478 views); M151328 (475 views); M151330 (450 views); M151372 (445 views); M151362 (406 views); M151363 (454 views); M151295 (485 views); M151323 (428 views); M151281 (435 views); M151451 (195 views); M151446 (241 views); M151369 (469 views); M151618 (268 views); M151368 (434 views); M151329 (465 views); M151356 (438 views); M151374 (504 views); M151365 (511 views); M151285 (437 views); M151354 (377 views); M151312 (415 views); M151359 (474 views); M151301 (472 views); M151311 (459 views); M151320 (407 views); M151396 (420 views); M151293 (438 views); M151383 (471 views); M151380 (442 views); M151408 (198 views); M151333 (463 views); M151357 (431 views); M151367 (384 views); M151303 (377 views); M151459 (155 views); M151491 (185 views); M151370 (437 views); M151386 (444 views); M151472 (187 views); M151353 (439 views); M151385 (418 views); M151390 (469 views); M151299 (447 views); M151437 (172 views); M151375 (433 views); M151283 (559 views); M151393 (438 views); M151307 (444 views); M151468 (171 views); M151316 (452 views); M151436 (155 views); M151401 (238 views); M151484 (211 views); M151443 (190 views); M151378 (469 views); M151428 (200 views); M151457 (166 views); M151441 (185 views); M151394 (482 views); M151317 (414 views); M151387 (446 views); M151382 (465 views); M151489 (213 views); M151366 (416 views); M151306 (405 views); M151454 (193 views); M151282 (554 views); M151298 (430 views); M151326 (466 views); M151361 (431 views); M151325 (435 views); M151324 (495 views); M151371 (451 views); M151360 (409 views); M151617 (295 views); M151331 (439 views); M151391 (389 views); M151381 (442 views); M151300 (400 views); M151377 (378 views); M151297 (538 views); M151310 (405 views); M151314 (467 views); M151632 (219 views); M151342 (422 views); M151389 (450 views); M151628 (187 views); M151373 (462 views); M151421 (196 views); M151442 (217 views); M151341 (437 views); M151395 (471 views); M151469 (202 views); M151304 (497 views); M151379 (435 views); M151313 (437 views); M151322 (461 views); M151327 (399 views); M151343 (436 views); M151345 (391 views); M151358 (442 views); M151318 (462 views); M151315 (449 views); M151321 (441 views); M151405 (172 views); M151364 (466 views); M151388 (416 views); M151309 (471 views); M151440 (159 views); M151344 (390 views); M151296 (426 views); M151418 (246 views); M151458 (237 views); M151352 (455 views); M151466 (229 views); M151319 (429 views); M151585 (182 views); M151586 (194 views); M151587 (211 views); M151588 (198 views); M151589 (153 views); M151590 (175 views); M151616 (240 views); M151619 (193 views); M151620 (175 views); M151621 (201 views); M151629 (195 views); M151630 (207 views); M151631 (178 views); M151633 (228 views); M151634 (218 views); M151635 (187 views); M151636 (190 views); M151637 (190 views); M151638 (169 views); M151639 (231 views); M151376 (435 views); M151474 (193 views); M151305 (461 views); M151384 (469 views); M151302 (419 views); M151397 (399 views); M151355 (458 views); M151286 (399 views); M151294 (464 views); M151332 (417 views); M151392 (450 views); M151308 (492 views); M151479 (250 views); M151414 (177 views); M151465 (156 views); M151400 (187 views); M151462 (186 views); M151470 (213 views); M151420 (201 views); M151430 (182 views); M151402 (180 views); M151485 (205 views); M151447 (169 views); M151435 (190 views); M151398 (220 views); M151407 (195 views); M151492 (208 views); M151449 (153 views); M151488 (185 views); M151399 (204 views); M151452 (194 views); M151471 (175 views); M151406 (231 views); M151413 (181 views); M151412 (184 views); M151429 (190 views); M151403 (197 views); M151404 (188 views); M151409 (200 views); M151410 (201 views); M151411 (252 views); M151415 (179 views); M151416 (187 views); M151417 (173 views); M151419 (202 views); M151431 (155 views); M151432 (180 views); M151433 (211 views); M151434 (152 views); M151438 (189 views); M151439 (186 views); M151444 (183 views); M151445 (208 views); M151448 (192 views); M151450 (224 views); M151453 (176 views); M151455 (191 views); M151456 (184 views); M151460 (206 views); M151461 (186 views); M151463 (174 views); M151464 (166 views); M151467 (285 views); M151473 (190 views); M151475 (189 views); M151476 (183 views); M151477 (191 views); M151478 (201 views); M151480 (210 views); M151481 (185 views); M151482 (176 views); M151483 (202 views); M151486 (176 views); M151487 (227 views); M151490 (187 views); M151493 (221 views);
    Bibliography2228
    Documents list1716
    Specimen list23809
    Taxon list11479




    Project downloads

    type number of downloads Individual items downloaded (where applicable)
    Total downloads from project267
    Media downloads11M151280 (5 downloads); M151295 (1 download); M151369 (1 download); M151618 (1 download); M151374 (1 download); M151362 (1 download); M151304 (1 download);
    Project downloads223
    Matrix downloads22Discrete Matrix (22 downloads);
    Document downloads11Continuous Character Matrix (6 downloads); Combined Discrete and Continuous Character Matrix (5 downloads);