Fishing for Teeth

Life on Earth is the result of millions of years of fine-tuning – an evolution which often hides details of how things gradually became the way they are in extinct species, for curious scientists to discover. Here they use high-resolution x-ray microtomography to picture the jawbone of a fossilised bony fish Lophosteus, revealing its 422-million-year-old teeth (highlighted in gold) and virtually 'removing'the bone to peek at the blood vessels and pulp cavities (blue and green) underneath. This fish was picked for a reason – it’s an early window into the evolution of teeth, showing that structures called dermal odontodes (purple pink and red) developed from similar cells to teeth, becoming nearby 'skin teeth' – the scales in fish like sharks. The co-development of these structures reveals more about the chemical signals driving how teeth develop and grow, and may provide insights into the signals shaping human gnashers too.

Written by John Ankers

John Ankers

Writer

A former researcher in systems biology, John is now an online biology tutor and professional coach supporting the wellbeing of scientists and NHS professionals. He's writing, too, of course.

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• Image from work by Donglei Chen and colleagues
• Department of Organismal Biology, Uppsala University, Uppsala, Sweden
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in eLife, December 2020