Tags

Type your tag names separated by a space and hit enter

Small body size and extreme cortical bone remodeling indicate phyletic dwarfism in Magyarosaurus dacus (Sauropoda: Titanosauria).
Proc Natl Acad Sci U S A. 2010 May 18; 107(20):9258-63.PN

Abstract

Sauropods were the largest terrestrial tetrapods (>10(5) kg) in Earth's history and grew at rates that rival those of extant mammals. Magyarosaurus dacus, a titanosaurian sauropod from the Upper Cretaceous (Maastrichtian) of Romania, is known exclusively from small individuals (<10(3) kg) and conflicts with the idea that all sauropods were massive. The diminutive M. dacus was a classical example of island dwarfism (phyletic nanism) in dinosaurs, but a recent study suggested that the small Romanian titanosaurs actually represent juveniles of a larger-bodied taxon. Here we present strong histological evidence that M. dacus was indeed a dwarf (phyletic nanoid). Bone histological analysis of an ontogenetic series of Magyarosaurus limb bones indicates that even the smallest Magyarosaurus specimens exhibit a bone microstructure identical to fully mature or old individuals of other sauropod taxa. Comparison of histologies with large-bodied sauropods suggests that Magyarosaurus had an extremely reduced growth rate, but had retained high basal metabolic rates typical for sauropods. The uniquely decreased growth rate and diminutive body size in Magyarosaurus were adaptations to life on a Cretaceous island and show that sauropod dinosaurs were not exempt from general ecological principles limiting body size.

Links

PMC Free PDF
PMC Free Full Text
FREE Publisher Full Text

Authors+Show Affiliations

Stein K
Steinmann Institute Division of Paleontology, University of Bonn, 53115 Bonn, Germany. koen.stein@uni-bonn.de
Csiki Z
No affiliation info available
Rogers KC
No affiliation info available
Weishampel DB
No affiliation info available
Redelstorff R
No affiliation info available
Carballido JL
No affiliation info available
Sander PM
No affiliation info available

MeSH

AnimalsBody SizeBody Weights and MeasuresBone DevelopmentBone RemodelingBone and BonesDinosaursDwarfismFossilsGeographyRomania

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

20435913

Citation

Stein, Koen, et al. "Small Body Size and Extreme Cortical Bone Remodeling Indicate Phyletic Dwarfism in Magyarosaurus Dacus (Sauropoda: Titanosauria)." Proceedings of the National Academy of Sciences of the United States of America, vol. 107, no. 20, 2010, pp. 9258-63.
Stein K, Csiki Z, Rogers KC, et al. Small body size and extreme cortical bone remodeling indicate phyletic dwarfism in Magyarosaurus dacus (Sauropoda: Titanosauria). Proc Natl Acad Sci U S A. 2010;107(20):9258-63.
Stein, K., Csiki, Z., Rogers, K. C., Weishampel, D. B., Redelstorff, R., Carballido, J. L., & Sander, P. M. (2010). Small body size and extreme cortical bone remodeling indicate phyletic dwarfism in Magyarosaurus dacus (Sauropoda: Titanosauria). Proceedings of the National Academy of Sciences of the United States of America, 107(20), 9258-63. https://doi.org/10.1073/pnas.1000781107
Stein K, et al. Small Body Size and Extreme Cortical Bone Remodeling Indicate Phyletic Dwarfism in Magyarosaurus Dacus (Sauropoda: Titanosauria). Proc Natl Acad Sci U S A. 2010 May 18;107(20):9258-63. PubMed PMID: 20435913.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Small body size and extreme cortical bone remodeling indicate phyletic dwarfism in Magyarosaurus dacus (Sauropoda: Titanosauria). AU - Stein,Koen, AU - Csiki,Zoltan, AU - Rogers,Kristina Curry, AU - Weishampel,David B, AU - Redelstorff,Ragna, AU - Carballido,Jose L, AU - Sander,P Martin, Y1 - 2010/04/30/ PY - 2010/5/4/entrez PY - 2010/5/4/pubmed PY - 2010/7/23/medline SP - 9258 EP - 63 JF - Proceedings of the National Academy of Sciences of the United States of America JO - Proc Natl Acad Sci U S A VL - 107 IS - 20 N2 - Sauropods were the largest terrestrial tetrapods (>10(5) kg) in Earth's history and grew at rates that rival those of extant mammals. Magyarosaurus dacus, a titanosaurian sauropod from the Upper Cretaceous (Maastrichtian) of Romania, is known exclusively from small individuals (<10(3) kg) and conflicts with the idea that all sauropods were massive. The diminutive M. dacus was a classical example of island dwarfism (phyletic nanism) in dinosaurs, but a recent study suggested that the small Romanian titanosaurs actually represent juveniles of a larger-bodied taxon. Here we present strong histological evidence that M. dacus was indeed a dwarf (phyletic nanoid). Bone histological analysis of an ontogenetic series of Magyarosaurus limb bones indicates that even the smallest Magyarosaurus specimens exhibit a bone microstructure identical to fully mature or old individuals of other sauropod taxa. Comparison of histologies with large-bodied sauropods suggests that Magyarosaurus had an extremely reduced growth rate, but had retained high basal metabolic rates typical for sauropods. The uniquely decreased growth rate and diminutive body size in Magyarosaurus were adaptations to life on a Cretaceous island and show that sauropod dinosaurs were not exempt from general ecological principles limiting body size. SN - 1091-6490 UR - https://www.unboundmedicine.com/medline/citation/20435913/Small_body_size_and_extreme_cortical_bone_remodeling_indicate_phyletic_dwarfism_in_Magyarosaurus_dacus__Sauropoda:_Titanosauria__ L2 - http://www.pnas.org/cgi/pmidlookup?view=long&amp;pmid=20435913 DB - PRIME DP - Unbound Medicine ER -