Microstructure study of sauropod bone from Mongolia

A sauropod femur found in 1963 in the Baynshire Formation (Cenomanian–Santonian) in Mongolia had been identified as belonging to a subadult representative of Titanosauriformes. The presence of characteristic bone tissue (modified laminar bone, MLB) indicating slow growth rate was identified in the bone microstructure of that specimen. This type of tissue is present in Titanosauriformes that are smaller in size (up to 18 m long). The presence of MLB in the analyzed specimen of a larger size (ca. 20 m long) implies that titanosauriforms with slower growth rates could also achieve large body sizes, like sauropods with faster growth rates.

Figure: 3D model of the analyzed femur, schematic reconstruction of a titanosauriform (Phylopic, author: Tasman Dixon), and a fragment of the cross-section through the femur showing secondary osteons scattered in modified laminar bone.