Musculoskeletal system of head-first burrowers: an interdisciplinary approach: a functional morphological analysis of postcranial adaptations

Project focus

Our project, funded by the Human Frontier Science Foundation (HFSP) delves into the fascinating world of amphisbaenians, a group of mainly limbless lizards found globally in tropical or subtropical environments. These unique creatures, known for their head-first burrowing behavior, exhibit robust skulls, reduced or absent eyes, and short, strong jaws. With around 200 species, amphisbaenians display four distinct skull morphologies: round, spade, keel, and shovel-headed. This diversity makes them an ideal group to study their cranial musculoskeletal system in a multiscale and multimodal fashion.

This multidisciplinary and international project aims to provide a holistic insight into the cranial musculoskeletal system of these burrowers. We will explore the underlying genetic factors behind their skull development and assess their biomechanics in an evolutionary and ecological context. While previous studies have focused on the macrostructure of their skulls, our project will delve deeper into the cranial nano/microstructure and material properties. We aim to answer questions about the functional and biomechanical significance of different skull morphologies, the roles of soft tissues within their heads, and the genetic relationships among different species.

By combining various scientific approaches, our project seeks to uncover the intricate details of amphisbaenian skulls and their adaptations to their environments. This research will not only enhance our understanding of these remarkable creatures but also contribute to the broader field of evolutionary biology and biomechanics. Join us on this exciting journey as we unravel the mysteries of amphisbaenian heads and their unique adaptations.

The role of our research group is to study the functional morphology related to postcranial kinematics that drives head-first burrowing, and testing hypotheses on adaptive evolution associated with the so-called internal concertina movement. We will map the 3D musculoskeletal architecture of the neck and postcranial system using iodine and/or PMA enhanced CT imaging, in collaboration with the UGent CT-facility (UGCT). Detailed 3D models will be analyzed with Amira and Blender software to understand the spatial architecture of key muscles and their integration with the skeleton and skin. Muscle fiber type distribution will be explored using immunohistochemistry analyses, and the structural organization of the skin will be studied using regular histology. Additionally, elastin presence and collagen fiber orientation will be checked using specific staining techniques.

Collaborators

The international team:

• Mehran Moazan (University College London, UK) – PI
• Tiana Kohlsdorf (University of Sao Paolo, Brazil)
• Henrik Birkedal (Aarhus University, Denmark)
• Dominique Adriaens (Ghent University, Belgium)

UGent project collaborators:

• Dominique Adriaens (PI)
• Morgane Taillades (PhD-student, Biology)
• Barbara De Kegel (Lab technician)

Keywords

amphisbaenia, head-first burrowing, 3D anatomy, biomechanics