Reference Terms
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Animal shell
A shell is a hard, rigid outer layer, which has evolved in a very wide variety of different animals, including mollusks, sea urchins, crustaceans, turtles and tortoises, armadillos, etc. Scientific names for this type of structure include exoskeleton, test, carapace, and peltidium.
The shells that are perhaps most familiar and most commonly encountered, both in the wild and for sale as decorative objects, are seashells, more precisely, the external shells of marine mollusks. These are usually primarily composed of calcium carbonate, in the form of calcite or aragonite crystallised out in an organic matrix. Calcium carbonate in mollusc shells can take different crystalline forms, one being nacre otherwise known as mother of pearl.
Other kinds of animal shells are made from chitin, bone and cartilage, or silica.
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January 7, 2026
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Jan. 1, 2026 Moss may look insignificant, but it can carry a hidden forensic fingerprint. Because different moss species thrive in very specific micro-environments, tiny fragments can reveal exactly where a person has been. Researchers reviewing 150 years of ...
Dec. 28, 2025 When researchers lowered whale bones into the deep ocean, they expected zombie worms to quickly move in. Instead, after 10 years, none appeared — an unsettling result tied to low-oxygen waters in the region. These worms play a key role in breaking ...
Dec. 27, 2025 UBC Okanagan researchers have uncovered how plants create mitraphylline, a rare natural compound linked to anti-cancer effects. By identifying two key enzymes that shape and twist molecules into their final form, the team solved a puzzle that had ...
Dec. 24, 2025 The search for life on Earth is speeding up, not slowing down. Scientists are now identifying more than 16,000 new species each year, revealing far more biodiversity than expected across animals, plants, fungi, and beyond. Many species remain ...
Dec. 22, 2025 Washing machines release massive amounts of microplastics into the environment, mostly from worn clothing fibers. Researchers at the University of Bonn have developed a new, fish-inspired filter that removes over 99% of these particles without ...
Dec. 22, 2025 A Brazilian study has confirmed that Joseph’s Coat, a plant used for generations in folk medicine, can significantly reduce inflammation and arthritis symptoms in lab tests. Researchers observed less swelling, healthier joints, and signs of tissue ...
Dec. 21, 2025 Old military air samples turned out to be a treasure trove of biological DNA, allowing scientists to track moss spores over 35 years. The results show mosses now release spores up to a month earlier than in the 1990s. Even more surprising, the ...
Dec. 16, 2025 Scientists are uncovering a surprising way to influence bacteria—not by killing them, but by changing how they communicate. Researchers studying oral bacteria found that disrupting chemical signals used in bacterial “conversations” can shift ...
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Jan. 7, 2026 Researchers have reconstructed ancient herpesvirus genomes from Iron Age and medieval Europeans, revealing that HHV-6 has been infecting humans for at least 2,500 years. Some people inherited the ...
Jan. 6, 2026 Dogs began diversifying thousands of years earlier than previously believed, with clear differences in size and shape appearing over 11,000 years ago. A massive global analysis of ancient skulls ...
Jan. 6, 2026 Researchers discovered that a poison frog species described decades ago was based on a mix-up involving the wrong museum specimen. The frog tied to the official species name turned out to be brown, ...
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Jan. 1, 2026 Scientists are uncovering new clues that a cosmic explosion may have rocked Earth at the end of the last ice age. At major Clovis-era sites, researchers found shocked quartz—evidence of intense ...
Dec. 31, 2025 A strange little snake fossil found on England’s south coast has finally revealed its secrets—more than 40 years after it was discovered. The newly named Paradoxophidion richardoweni lived around ...
Dec. 30, 2025 Environmental change doesn’t affect evolution in a single, predictable way. In large-scale computer simulations, scientists discovered that some fluctuating conditions help populations evolve ...
Dec. 30, 2025 A spectacular fossil trove on the Arctic island of Spitsbergen shows that marine life made a stunning comeback after Earth’s greatest extinction. Tens of thousands of fossils reveal fully aquatic ...
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