The iconic monitor lizards of Australia, commonly known as goannas, have long been a symbol of the country’s unique wildlife. However, beneath their scaly skin lies an unexpected secret: a hidden layer of bony skin structures known as osteoderms. These structures, which were previously thought to be rare in lizards, are found in nearly half of all lizard species worldwide and may hold the key to understanding how these ancient reptiles not only survived but thrived in one of the world’s harshest environments.

A recent study published in the prestigious Zoological Journal of the Linnean Society has shed new light on the widespread presence of osteoderms in lizards. The research, which was conducted by an international team of scientists from Australia, Europe, and the United States, used cutting-edge micro-CT scanning to examine nearly 2,000 reptile specimens from major museum collections.

“We were astonished to find osteoderms in 29 Australo-Papuan monitor lizard species that had never been documented before,” said Roy Ebel, lead author and researcher at Museums Victoria Research Institute and the Australian National University. “It’s a fivefold increase in known cases among goannas.”

Osteoderms are most commonly associated with crocodiles, armadillos, and even some dinosaurs like Stegosaurus. However, their function has remained something of an evolutionary mystery. While they may provide protection, scientists now suspect that osteoderms may also support heat regulation, mobility, and calcium storage during reproduction.

This new research reveals that osteoderms are far more widespread in lizards than previously thought, occurring in nearly half of all lizard species worldwide – an 85% increase on earlier estimates. The findings have significant implications for our understanding of reptile evolution and the adaptation of these ancient creatures to harsh environments.

At the heart of this discovery lies the power of museum collections. Scientific institutions like Museums Victoria Research Institute play a critical role in preserving biodiversity through time, enabling researchers to study species long after they were collected. Many of the specimens used in this study were decades, and in some cases over 120 years old, but advances in imaging technology enabled scientists to uncover new insights without harming the original material.

“What’s so exciting about this finding is that it reshapes what we thought we knew about reptile evolution,” said Dr Jane Melville, Museums Victoria Research Institute Senior Curator of Terrestrial Vertebrates. “It suggests that these skin bones may have evolved in response to environmental pressures as lizards adapted to Australia’s challenging landscapes.”

The discovery of osteoderms in monitor lizards opens up new questions about how these lizards adapted, survived, and diversified across the continent. This landmark study not only tells a new chapter in the story of Australia’s goannas but provides a powerful new dataset for exploring how skin, structure, and survival have intertwined across millions of years of evolution.

The article highlights groundbreaking research conducted at Edith Cowan University, where scientists have discovered an innovative way to extend the storage life of mangoes by up to 28 days. Led by Dr Mekhala Vithana, the study reveals that dipping mangoes in ozonated water for 10 minutes before cold storage significantly reduces chilling injury and extends shelf life.

Mango lovers rejoice! The research is a game-changer for growers and traders alike, as it reduces food loss during storage and provides a longer market window. With the global demand for fruits and vegetables on the rise, this eco-friendly technology could minimize post-harvest losses of mangoes and reduce waste in Australia.

Traditionally, mangoes are stored at 13 degrees Celsius for up to 14 days, but this temperature is not cold enough to prevent chilling injury. Prolonged storage below 12.5 degrees causes physiological disorders that damage the fruit skin and lead to decreased marketability and significant food waste.

The study tested aqueous ozonation technology on Australia’s most widely produced mango variety, Kensington Pride, and found that dipping the mango in ozonated water for 10 minutes prior to cold storage at 5 degrees Celsius extended shelf life up to 28 days with much less chilling injury. This breakthrough could revolutionize the way we store mangoes and reduce food waste.

Dr Vithana emphasizes that aqueous ozonation is a cost-effective, controlled-on-site technology that can be used in commercial settings. The researchers hope to conduct further studies on other varieties of mangoes to test their responsiveness and achieve further reduction in chilling injury for extended cold storage.

As we continue to explore innovative solutions to reduce food waste, the ozone secret could hold the key to extending mango storage life by 28 days, benefiting both growers and consumers alike.

The research team at City University of Hong Kong has made a groundbreaking discovery in understanding the anatomy of blue sharks (Prionace glauca). Led by Dr. Viktoriia Kamska, they have revealed a unique nanostructure in the shark’s skin that produces its iconic blue coloration. This remarkable mechanism lies within the pulp cavities of the tooth-like scales – known as dermal denticles – that armor the shark’s skin.

The secret to the shark’s color lies in the combination of guanine crystals, which act as blue reflectors, and melanin-containing vesicles called melanosomes, which absorb other wavelengths. This collaboration between pigment (melanin) and structured material (guanine platelets of specific thickness and spacing) enhances color saturation.

When these components are packed together, they create a powerful ability to produce and change color. Dr. Kamska explains that the cells containing the crystals can be observed to see how they influence the color of the whole organism. This anatomical breakthrough was made possible using a range of imaging techniques, including fine-scale dissection, optical microscopy, electron microscopy, spectroscopy, and computational simulations.

The discovery also reveals that the shark’s trademark color is potentially mutable through tiny changes in the relative distances between layers of guanine crystals within the denticle pulp cavities. Increasing this space shifts the color into greens and golds. Dr. Kamska and her team have demonstrated that this structural mechanism of color change could be driven by environmental factors such as humidity or water pressure changes.

For example, the deeper a shark swims, the more pressure its skin is subjected to, which should darken the shark’s color to better suit its surroundings. The next step is to see how this mechanism really functions in sharks living in their natural environment.

This research has strong potential for bio-inspired engineering applications. Dr. Kamska notes that structural coloration reduces toxicity and environmental pollution compared to chemical coloration. It could be a tool to improve environmental sustainability within the manufacturing industry, especially in marine environments where dynamic blue camouflage would be useful.

As nanofabrication tools get better, this creates a playground to study how structures lead to new functions. The research has been presented at the Society for Experimental Biology Annual Conference in Antwerp, Belgium on July 9th, 2025, and is being funded by Hong Kong’s University Grants Committee and General Research Fund.