Evaluation of Long Bone Surface Textures as Ontogenetic Indicators in Centrosaurine Ceratopsids

Abstract

The search for criteria for aging non-mammalian fossil vertebrates has preoccupied paleobiologists in recent years. Previous studies of the long bones of pterosaurs and modern and subfossil birds as well as of cranial material of centrosaurine ceratopsid dinosaurs have documented variations in surface textures that seem to be ontogenetically related. In this study, long bones from the centrosaurine ceratopsid genera Centrosaurus, Einiosaurus, and Pachyrhinosaurus are examined to test the hypothesis that changes in bone surface textures and reduction of surface porosity could be correlated with size (and presumably age) classes, as has been previously documented in pterosaurs and birds. The data set includes 141 bones representing all six long bone elements, collected from monodominant centrosaurine bone beds. Bone surface patterns are documented by macroscopic visual examination, and a sequence of five texture classes ordered by decreasing surface porosity is described based on the common distributions of these patterns. Calculations of Spearman's rank correlation coefficients reveal significant correlations between texture class and size. The smallest bones are invariably associated with porous midshaft textures that grade to fibrous and long-grained patterns proximally and distally [Texture Class (TC) 1]. Post-hoc analysis after Kruskal-Wallis ANOVA on ranks confirms that the mean size of TC1 bones is, in most cases, significantly different than the mean size of bones in other texture classes. Results of this study suggest the presence of an ontogenetic surface textural signal in centrosaurine long bones; however, comparison of texture classes with size-independent maturity criteria is needed to clarify further the potential ontogenetic significance of higher texture classes. Anat Rec, 292:1485Rec, 292: -1500Rec, 292: , 2009. V V C 2009 Wiley-Liss, Inc.

Ontogeny of Surface Texture of Limb Bones in Modern Aquatic Birds and Applicability of Textural Ageing

“…Comparative study of skeletal development of major limb bones in the postnatal ontogeny of five modern birds showed a consistent pattern of ontogenetic transition of surface textures, as well as interspecific variation in the relative timing of transitions. Histological observations, combined with morphometric examination published elsewhere (Watanabe, ), revealed that rough surface textures are indicative of the active circumferential growth of long bones, confirming the relationship between surface textures and growth regimes (Tumarkin‐Deratzian et al, ; Tumarkin‐Deratzian, ). The active circumferential growth of long bones generally persists after the time of fledging, and seems to cease before the time of sexual maturity, although the exact timing of the cessation is not clear (Watanabe, ).…”

“…A common method of ontogenetic ageing for vertebrate bones is the one based on the inspection of bone surface texture (textural ageing; Tumarkin-Deratzian et al, 2006, 2007Tumarkin-Deratzian, 2009). Textural ageing relies on transitions of bone surface textures in (postnatal) ontogeny, which reflects ontogenetic variation of histological structures of the bone matrix underlying the surface, and ultimately bone growth rate.…”

Histological evidence for muscle insertion in extant amniote femora: implications for muscle reconstruction in fossils

“…9A). A frayed surface in section may also be associated with long-grained bone texture in juvenile dinosaurs (Tumarkin-Deratzian et al 2006;Brown et al 2009;Tumarkin-Deratzian, 2009).…”

Bone Histology in Dysalotosaurus lettowvorbecki (Ornithischia: Iguanodontia) – Variation, Growth, and Implications

“…Size classes within a bonebed of a single species, surface texture of bones, or degree of suture closure are examples of tools often used to estimate relative age and ontogenetic status of fossil animals, but these methods are always highly imprecise (e.g. [1] – [4] ). The study of bone histology has enabled paleontologists partially filling this methodological gap, because its insights can provide the required absolute data in many cases (see e.g.…”