Project 1218: T. M. Cullen, D. C. Evans, M. J. Ryan, P. J. Currie, Y. Kobayashi. 2014. Osteohistological variation in growth marks and osteocyte lacunar density in a theropod dinosaur (Coelurosauria: Ornithomimidae). BMC Evolutionary Biology.
Specimen: † Ornithomimus edmontonicus (ROM:852)


Osteohistological examinations of fossil vertebrates have utilized a number of proxies, such as counts and spacing of lines of arrested growth (LAGs) and osteocyte lacunar densities (OLD), in order to make inferences related to skeletochronology and mass-specific growth rates. However, many of these studies rely on samplings of isolated bones from single individuals. These analyses do not take individual variation into account, and as a result may lead to misleading inferences of the physiology of extinct organisms. This study uses a multi-element, multi-individual sampling of ornithomimid dinosaurs to test the amount of individual variation in the aforementioned osteohistological indicators. Based on these results we also assess the conclusions of previous studies that tested paleohistological hypotheses using isolated elements

LAG number was found to be consistent within the hind limb bones of each individual, with the exception of the fibula, which preserves one additional LAG. Considerable differences in LAG spacing were found between elements of the sampled individuals, with larger variation found in elements of the foot compared with the femur, fibula, and tibia. Osteocyte lacunar density ranged between 29000 and 42000 osteocyte lacunae per mm3, and was found to vary more between hind limb bones of an individual and within bones, than between the average values of individuals.

The variation in LAG number and LAG spacing between hind limb elements suggests that direct comparisons of these elements may be misleading, and that LAG spacing is not a reliable proxy for mass-specific growth rates of an individual. Sampling of multiple bones should be performed as an internal check of model-based LAG retrocalculation and growth equations. The observation that osteocyte lacunar density varies more between individual bone elements than between average individual values suggests that, the choice of sampled element can greatly influence the result, and care should be taken to not bias interpretations of the physiology of fossil tetrapods.

Read the article »

Article DOI: 10.1186/s12862-014-0231-y

Project DOI: 10.7934/P1218,
This project contains
  • 40 Media
  • 2 Taxa
  • 4 Specimens
Total size of project's media files: 225 MB

Download Project SDD File
Currently Viewing:
MorphoBank Project 1218


    member name taxa specimens media media
    Thomas Cullen
    Project Administrator
    Last logged in 12/01/14

    Project has no matrices defined.

    Project views

    type number of views Individual items viewed (where applicable)
    Total project views25944
    Project overview3101
    Media views19394Media search (3977 views); M333237 (381 views); M339654 (424 views); M339651 (363 views); M339646 (393 views); M333245 (386 views); M339649 (350 views); M333258 (354 views); M333255 (372 views); M333252 (373 views); M339656 (386 views); M333239 (371 views); M339652 (384 views); M339645 (399 views); M333259 (356 views); M333261 (388 views); M333263 (412 views); M333257 (374 views); M333262 (361 views); M333246 (354 views); M333240 (395 views); M333254 (338 views); M333244 (395 views); M333253 (406 views); M333256 (375 views); M333250 (417 views); M333247 (391 views); M333236 (404 views); M339653 (376 views); M339655 (391 views); M333243 (442 views); M339650 (393 views); M333249 (381 views); M339648 (385 views); M333251 (392 views); M333238 (364 views); M339647 (392 views); M333241 (400 views); M333248 (417 views); M333242 (415 views); M333260 (367 views);
    Specimen list2338
    Taxon list1111

    Project downloads

    type number of downloads Individual items downloaded (where applicable)
    Total downloads from project185
    Media downloads29M333239 (3 downloads); M333260 (4 downloads); M333245 (4 downloads); M333236 (4 downloads); M333243 (2 downloads); M333238 (2 downloads); M339645 (1 download); M333261 (2 downloads); M333244 (3 downloads); M333241 (2 downloads); M333240 (1 download); M333242 (1 download);
    Project downloads156