Lapworth Lecture - Mapping Out Shark’s Alternative to Bone

Sharks and their relatives have thrived for over 430 million years—predating trees—and have survived four major mass extinctions. With remarkable morphological diversity, they occupy habitats from coastal shallows to depths beyond 3,700 metres, often serving as apex predators. This extraordinary evolutionary success is linked to a key innovation: a lightweight skeleton made entirely of cartilage. Central to this is a thin outer layer of calcified tiles called tesserae—a skeletal tissue found only in sharks. Tesserae provides the skeleton with strength, flexibility, and low weight, yet the evolution, function, and adaptability of this important tissue remains poorly understood.

In this talk, Hannah will discuss her MSCA postdoctoral project, which utilizes high-resolution scanning of modern and fossil sharks to investigate the evolution of tesserae in 3D. She will showcase 3D models of modern shark jaws to reveal surprising variation in tesserae shape, size, and density. The drivers behind this variation are complex, with function, phylogeny, and ontogeny all playing key roles. Finally, she will present preliminary findings from fossil scan data and discuss how this research can inform medical studies on osteoarthritis and innovations in materials engineering.

About Hannah

Hannah is an MSCA Postdoctoral Fellow at Naturalis Biodiversity Center in the Netherlands. After earning an MSci in Marine Biology and Oceanography from Bangor University, her fascination with evolution led her to a PhD at Uppsala University, Sweden. There, she used high-resolution scanning to investigate ecosystem recovery after the Late Devonian mass extinction using fossil poo! Today, Hannah blends her expertise in marine science, evolution, and palaeontology to explore the evolution of calcified cartilage in sharks. Her ultimate goal is to bridge the gap between the study of fossils and living species.