Development-based revision of bone tissue classification: the importance of semantics for science

Abstract

Research on the bone histology of extant and extinct animals has a long scientific history and an accurate description of microstructural tissues is the cornerstone of the field. Ideally, terminology needs to convey as much information as possible about the structural, developmental, and functional aspects of bone tissues corresponding to the up-to-date knowledge of the time. However, current terms are not always consistent with new observations and advances in the field of bone biology. We provide a brief overview of some ambiguities and their origins, and suggest a new approach of bone tissue classification and description that is congruent with our current understanding of bone as a living tissue, emphasizing its developmental aspects. This approach requires the introduction of a new term, namely 'woven-parallel complex', for describing a broad range of complex bone tissue types, including intramembranous and endochondral bones, and different types of primary as well as secondary bone tissues. We reconsider the classical concept of fibrolamellar complex, which we place within the new developmental approach. Finally, using non-archosaurian archosauromorphs as an example group, we demonstrate how the new approach can be utilized in an evolutionary context. The present study demonstrates the relevance and constant evolution of technical terminology along with the advances of the field of science.

Medullary bone-like tissue in the mandibular symphyses of a pterosaur suggests non-reproductive significance

“…It is highly vascularized by unusually wide canals and sinuses. The bony struts separated by these wide vascular spaces show low birefringence, and contain mostly spatially unorganized, irregularly shaped lacunae apparently derived from static osteogenesis (SO) [37][38][39] . On the other hand, lacunae adjacent to the endosteal lamellae and those around the intact vascular canals exhibit dynamic osteogenesis-derived (DO) [37][38][39] features (Figs 3b,d, and 4l).…”

“…The bony struts separated by these wide vascular spaces show low birefringence, and contain mostly spatially unorganized, irregularly shaped lacunae apparently derived from static osteogenesis (SO) [37][38][39] . On the other hand, lacunae adjacent to the endosteal lamellae and those around the intact vascular canals exhibit dynamic osteogenesis-derived (DO) [37][38][39] features (Figs 3b,d, and 4l). Thus, this loosely organized secondary medullary tissue is composed of a combination of woven and parallel-fibred bone with the former being the dominant component of the complex and supporting its fast growing nature.…”

“…not in a long bone), the highly porous, secondary intramedullary bone tissue found in four symphyses of Bakonydraco galaczi (Table 1) looks identical to medullary bone as identified and described in non-avian dinosaurs 21,27,28 . Based on its microanatomy and microstructure, the formation principles of this tissue is most likely similar to those of fibrolamellar bone (sensu Prondvai et al 39 ) developing in the periosteum of juveniles of fast growing animals [40][41][42][43] . The marked difference is that this tissue grows centripetally within the cavities, mostly on previously resorbed bone surface.…”

“…Histological descriptions and tissue identification follow the concept of Stein and Prondvai 38 and Prondvai et al 39 , vascular architecture categories that of FrancillonVieillot et al 73 . The current study focuses on the secondary bone structures found in these specimens; primary tissues have already been described in detail by Prondvai et al 36 .…”

Advances in vertebrate palaeohistology: recent progress, discoveries, and new approaches

“…In this contribution, Prondvai et al (2014) suggest a new, more integrative, approach for describing and classifying bone tissues based on their development. They notably constrain the definition of fibrolamellar bone and erect a new term, 'woven-parallel complex', to describe a broad range of complex osseous tissues.…”