Ancient jawless fish, dating back approximately 400 million years, grew the first bones containing living cells, offering essential minerals for the fish's muscle development.

In a groundbreaking study published in the journal Science Advances, researchers have uncovered a fascinating aspect of prehistoric life: the role of bone cells, known as osteocytes, in powering the long-distance travels of ancient fish.

The study, led by Yara Haridy, focuses on osteocytes, the cells that become walled-in by the hard, mineral part of bone as part of skeletal growth. These cells, it seems, turned bone tissue into a kind of battery, releasing stored minerals needed for bodily processes such as nourishing muscles.

This discovery sheds light on the capabilities of early bones, which acted as skeletal batteries, supplying prehistoric fish with minerals needed for long-distance travel. The earliest animals with bone didn't have osteocytes, leading paleontologists to wonder when and why these bone cells first developed.

The research reveals that the fossilised creatures in the analysis are known as osteostracans, also referred to as "beetle mermaids" by Yara Haridy. These ancient fish had a hard, armor-encased front end and a flexible tail growing out the back, with no jaws and bone tissue encasing their bodies.

The study was able to uncover the shape and connections of cells between bones, a first in the field. The scans revealed the cavities where bone cells lived inside the ancient fish, and the bone tissue around the cell cavities was eaten away due to the cells dissolving it for mineral release.

A new 3D technique called focused ion beam milling and scanning electron microscopy (FIB-SEM) was used to reveal bone structures that scientists have not previously been able to study. However, it's important to note that this technique can only look at bone tissue near the surface of the fossil and destroys that part during the process.

This research provides fresh evidence that early bone cells repurposed the armor of osteostracans to provide an extra boost of energy. Without developing cellular bones, fish probably wouldn't have been able to undertake long migrations due to the lack of necessary minerals.

The margins around osteocytes were found to be a lower density than the surrounding bone, suggesting mineral metabolism. These findings have the potential to uncover osteological secrets that could not be detected before, offering a deeper understanding of the evolution of bone cells and their role in the lives of ancient creatures.

This study not only offers insights into the past but also opens up avenues for further research into the role of bone cells in various species, including humans. As we continue to explore the mysteries of our past, we gain a better understanding of our present and future.

Ancient jawless fish, dating back approximately 400 million years, grew the first bones containing living cells, offering essential minerals for the fish's muscle development.