(Press-News.org) When we picture sea turtles in the wild, it’s easy to envision them as armored warriors – their hard, resilient shells serving as near-impenetrable shields against oceanic threats like sharks. These sleek, streamlined shells aren’t just defensive – they’re engineered for speed, efficiency and survival. Designed to minimize drag, they allow sea turtles to glide effortlessly through the water, dive to astonishing depths, and handle the immense pressure shifts as they surface.
A sea turtle’s shell is a complex masterpiece, made up of two parts: the carapace (top) and the plastron (bottom), both covered in scutes – tough keratin plates tightly attached to the bone. The bone forms a unique “sandwich” of dense outer bone and a lightweight, spongy core, combining strength, buoyancy and protection for the turtle’s muscles, nerves and vital organs.
But what is it about these material properties that give marine turtles’ shells such remarkable protection and agility? While much has been studied about the shells of freshwater turtles and land tortoises, marine turtles have received comparatively little attention.
To fill this gap, researchers from Florida Atlantic University dove deep into the biomechanical properties of the carapaces of three common sea turtle species from the North Atlantic: green turtles (Chelonia mydas), loggerheads (Caretta caretta) and Kemp’s ridleys (Lepidochelys kempii). Their findings have revealed surprising new insights into the development of these ocean-dwelling titans.
Using advanced compression tests and statistical models, the team examined the toughness, stiffness and strength of these turtles’ shells across many stages of life – from juveniles to adults.
Their results, published in the Journal of Experimental Biology, show that the shell bone complex of marine turtles plays a crucial role in balancing biomechanical trade-offs such as lower stiffness and a high degree of flexibility to protect them against predators and environmental stressors while also optimizing their ability to move efficiently through water. This unique adaptation highlights the complex and dynamic nature of marine turtle morphology, where the shell’s design must accommodate the demands of both survival and efficient locomotion in their aquatic habitats.
Although all three species share a similar structural design, they each display striking differences in how their shells respond to stress. Green turtles, for instance, boast the toughest, stiffest shells, with denser, stronger bones. Meanwhile, loggerheads have more flexible, porous carapaces, a design that is more compliant under pressure. These variations likely reflect each species’ evolutionary response to their unique environments and the threats they face.
Interestingly, the toughness of a turtle’s shell remains constant as it grows within each species.
“We believe this variation is likely a result of their evolution and the environments they inhabit,” said Ivana J. Lezcano, first author and doctoral student in the FAU Department of Biological Sciences within the Charles E. Schmidt College of Science. “The differences in shell stiffness across these species may be connected to their distinct life histories, with each species adapting to unique environmental challenges and predation risks.”
For both green turtles and Kemp’s ridleys, their shells become even stiffer and stronger as they grow larger, offering greater defense – especially as subadults and adults. Kemp’s ridleys, in particular, experience a faster increase in shell stiffness as they grow, possibly because they mature earlier and shift to foraging in riskier coastal waters.
“What’s fascinating is that their shells evolve to provide more protection over time,” said Lezcano. “The stiffness of juvenile green turtle shells may be especially important because their shells lack the protective spines and keels, which young loggerheads and ridleys sport to armor themselves against predators. It’s a dynamic interplay of form and function that ensures these turtles are built for survival.”
Loggerheads, however, didn’t show a significant change in shell stiffness across life stages. This slower development in shell stiffness could explain why they stay in the open ocean for a longer period, avoiding the more dangerous coastal habitats until they are larger and better protected.
Researchers also discovered that marine turtles’ shells respond to compression in a similar way to those of land turtles, which have a similar basic shell structure. The shell’s internal porous layer is key to its strength, allowing it to be both stiff and tough, which helps protect turtles from attacks like biting or clawing.
“The shells of adult sea turtles are surprisingly compliant compared to their land relatives,” said Jeanette Wyneken, Ph.D., co-author and a professor of biological sciences, FAU Charles E. Schmidt College of Science. “But here’s the cool part: while their shells become stronger over time, they don’t become completely rigid like the shells of land turtles. This flexibility is key – because it enables them to ‘flex the shell’ under pressure, which is crucial for navigating the harsh and varying conditions of underwater environments.”
This study not only uncovers the fascinating design of sea turtle shells but also reveals how nature has intricately fine-tuned these creatures for survival.
“Our study provides new insights into why sea turtles have thrived over time,” said Marianne Porter, Ph.D., co-author and an associate professor in the FAU Department of Biological Sciences. “Their shells are adapted to their aquatic lifestyle, and stiff enough to defend against predators while being tough enough to absorb shock. This remarkable balance of strength and flexibility has allowed them to survive in the ocean for millions of years – an example of evolution shaping species in an environment.”
- FAU -
About Florida Atlantic University:
Florida Atlantic University, established in 1961, officially opened its doors in 1964 as the fifth public university in Florida. Today, Florida Atlantic serves more than 30,000 undergraduate and graduate students across six campuses located along the Southeast Florida coast. In recent years, the University has doubled its research expenditures and outpaced its peers in student achievement rates. Through the coexistence of access and excellence, Florida Atlantic embodies an innovative model where traditional achievement gaps vanish. Florida Atlantic is designated as a Hispanic-serving institution, ranked as a top public university by U.S. News & World Report, and holds the designation of “R1: Very High Research Spending and Doctorate Production” by the Carnegie Classification of Institutions of Higher Education. Florida Atlantic shares this status with less than 5% of the nearly 4,000 universities in the United States. For more information, visit www.fau.edu.
END
The Korea Electrotechnology Research Institute (KERI) and the Korea Institute of Materials Science (KIMS) have jointly developed the 'spray drying technology-based high-performance dry electrode manufacturing technology' for the realization of high-capacity secondary batteries.
Secondary battery electrodes are made by mixing 'active materials' that store electrical energy, 'conductive additives' that help the flow of electricity, and 'binders' which act as a kind of adhesive. There are two methods for mixing these materials: the 'wet ...
Conventional food production and distribution systems degrade the environment due to several aspects, like overuse of fertilizers and high greenhouse gas emissions. This necessitates a shift towards low environmental impact, sustainable food systems like Community-Supported Agriculture (CSA). In CSA, consumers pay producers in advance for their harvest. In this way, farmers get financial stability, and consumers get a chance to engage in farming activities, which ultimately strengthens local food systems.
Despite its benefits, there are few studies on what makes consumers participate in CSA, particularly outside Western countries. Specifically, in Japan, where CSA ...
EMBARGOED UNTIL TUESDAY 8TH APRIL 13:25 CEST
CANNABIDIOL THERAPY COULD REDUCE SYMPTOMS IN AUTISTIC CHILDREN AND TEENAGERS
Tuesday 8th April, 13:25 CEST - New research presented at the 2025 European Congress of Psychiatry reveals that the use of cannabidiol (CBD) cannabis extract can lead to meaningful benefits and improve the behaviour of children and adolescents with autism spectrum disorder (ASD). ASD affects approximately 1 in 100 children around the world and symptoms can include difficulty interpreting language, ...
Every galaxy is thought to form at the center of a dark matter halo – a region of gravitationally bound matter that extends far beyond the visible boundaries of a galaxy. Stars are formed when gravity within dark matter halos draws in gas, but astrophysicists don’t yet know whether star-free dark matter halos exist.
Now Ethan Nadler, a computational astrophysicist at UC San Diego, has calculated the mass below which halos fail to form stars. This work was done using analytic predictions from galaxy formation theory and cosmological simulations.
"Historically, our understanding of dark matter has been ...
PROVIDENCE, R.I. [Brown University] — Just steps from the center of Tikal, a 2,400-year-old Maya city in the heart of modern-day Guatemala, a global team of researchers including scholars from Brown University have unearthed a buried altar that could unlock the secrets of a mysterious time of upheaval in the ancient world.
The altar, built around the late 300s A.D., is decorated with four painted panels of red, black and yellow depicting a person wearing a feathered headdress and flanked by shields ...
DALLAS, April 8, 2025 — For students to get their health into the endzone, a mix of various cardio and strength exercises that work different parts of the body is ideal for whole body health, according to the U.S. Department of Health and Human Services’ 2018 Physical Activity Guidelines for Americans. That is why the American Heart Association and the National Football League (NFL), in collaboration with the 32 teams, held the NFL PLAY 60 Exercise Blitz to get students moving leading up to Super Bowl LIX in New Orleans. Three schools, named the national winners of the Exercise Blitz, received $1,000 NFL PLAY 60 grants for improvements to the schools’ physical ...
A urinal designed to avoid urine splashback on the user and the floor will improve sanitation, bathroom cleanliness, and user experience.
Urinal designs have not materially changed in over a century. The style of urinal that was elevated to the status of artistic landmark by Marcel Duchamp in his 1917 dada art piece “La Fontaine” would not look out of place in today’s public restrooms. Use of a typical public urinal often results in splatter of urine outside the confines of the device—onto the floor and, most unpleasantly, onto the user, a situation that creates costly messes to clean and risks transmitting disease. Zhao Pan, Kaveeshan ...
When faced with a potential threat, mice often freeze in place. Moreover, when two animals are together, they typically freeze at the same time, matching each other’s periods of immobility.
In a new study, researchers found that coordination during fear looks different in males and females — and changes when stress is involved.
Male-female mouse pairs consistently stayed in sync during stressful situations, even when the animals were strangers. Same-sex pairs were more likely to fall out of step.
The findings, published in Biological Psychiatry Global Open Science, suggest that opposite-sex pairs may rely on a more flexible or complex coordination ...
Children with autism spectrum disorder (ASD) often experience social communication impairments and engage in restricted and repetitive behaviors (RRBs). Early identification of these symptoms is critical for timely intervention, but detecting RRBs, in particular, remains a challenge. Previous studies using eye-tracking methods have revealed that children with ASD tend to favor non-social stimuli over social ones, a preference that aligns with ASD symptoms. However, the developmental timeline of this preference—especially regarding repetitive versus random movements—remains poorly understood. Research has shown that children with ASD may spend ...
UTSA researchers recently completed one of the most comprehensive studies to date on the risks of using AI models to develop software. In a new paper, they demonstrate how a specific type of error could pose a serious threat to programmers that use AI to help write code.
Joe Spracklen, a UTSA doctoral student in computer science, led the study on how large language models (LLMs) frequently generate insecure code. His team’s paper has been accepted for publication at the USENIX Security Symposium 2025, a premier cybersecurity ...
