EVOMORPH — Theme PALEOHISTOLOGY

What factors explain the microstructural variations of mineralized tissues?

• Led by Alexandra Quilhac et Jorge Cubo 

This theme investigates the microstructure of skeletal tissues (bone, cartilage, and teeth) to decode the environmental factors and life history traits recorded within them. Because tissue architecture is often exceptionally preserved during fossilization, comparative studies with extant taxa allow us to build robust models for paleobiological and paleoenvironmental inference.

Our research addresses several fundamental questions: How can mineralized tissue structures be used to reconstruct life history, paleoecology, and environmental conditions? To what extent does taphonomy affect tissue preservation, and do these micro-structures retain a reliable phylogenetic signal? How are biomechanical constraints recorded at the tissue level, and how can this signal be used to infer the function of skeletal elements? Can mineralized tissues provide evidence for physiological traits, such as the thermometabolism of extinct vertebrates?

The resting metabolic rate of Azendohsaurus laaroussii was inferred using phylogenetic comparative methods, a sample of extant amniotes and the vascular density of a tibiae histological section as a proxy. Reconstruction of the organism by C. Letenneur, histological section by H. Lamrous, image layout by A. Lethiers. Results obtained were published in Cubo & Jalil 2019. doi:10.1017/pab.2019.13