Ordovician-Silurian extinction
The Ordovician-Silurian extinction, around 445 million years ago, was caused by a rapid ice age and fluctuating sea levels, eliminating nearly 85% of marine species.
Discover the fascinating creatures that once roamed our planet
Carboniferous
Arthropleura was the largest land invertebrate ever to exist! This giant millipede-like creature lived during the Carboniferous period, approximately 300 million years ago, and could grow up to 2.6 meters (8.5 feet) long—longer than most ...
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Jurassic
Ceratosaurus, meaning "horned lizard," was a distinctive predatory dinosaur famous for the horn on its nose! Living approximately 153-148 million years ago during the Late Jurassic, this medium-sized theropod ...
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Jurassic
Archaeopteryx, meaning "ancient wing," is one of the most important fossils ever discovered. Living approximately 150 million years ago during the Late Jurassic period, this ...
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April 14, 2026
Proterozoic
Charnia is one of the most important fossils ever discovered! This mysterious frond-shaped organism lived during the Ediacaran period, approximately 575 to 555 million years ago, making it one of Earth's oldest known complex life forms. Charnia was the...
April 14, 2026
Proterozoic
Tribrachidium is one of the strangest creatures to ever exist! Living during the Ediacaran period about 558-555 million years ago, this bizarre disc-shaped organism had three-fold symmetry — a body plan found in no living animal today. It...
April 14, 2026
Proterozoic
Spriggina is one of the most intriguing fossils from the Ediacaran period, living approximately 550-560 million years ago. With its distinctive horseshoe-shaped head and segmented body, it has sparked decades of debate about whether it represents...
April 14, 2026
Cambrian
Wiwaxia is one of the strangest creatures from the Cambrian Explosion, living approximately 508 million years ago. This bizarre armored slug-like animal was covered in overlapping scales and tall defensive spines, making...
April 14, 2026
Cambrian
Pikaia is one of the most important fossils ever discovered—it may be one of our earliest ancestors! This small, leaf-shaped swimmer lived approximately 508 million years ago during the Middle Cambrian period....
April 14, 2026
Cambrian
Olenoides serratus is one of the most famous and scientifically important trilobites ever discovered! Living approximately 508 million years ago during the Middle Cambrian, this trilobite is celebrated for its exceptional...
April 14, 2026
Cambrian
Ottoia was a fearsome predatory worm that terrorized the Cambrian seafloor approximately 508 million years ago. As the most abundant worm in the famous Burgess Shale, this priapulid (penis worm) used its...
February 2, 2026
Proterozoic
Dickinsonia is one of the most mysterious and ancient creatures ever found! Living during the Ediacaran period about 558-555 million years ago, it was one of Earth's earliest complex life forms. This bizarre oval-shaped organism lived...
February 2, 2026
Ordovician
Orthoceras was an ancient straight-shelled nautiloid—an early relative of today's squids and octopuses! Living from the Ordovician to Triassic periods (around 485-200 million years ago), these jet-propelled hunters had long, cone-shaped shells and were among the...
February 2, 2026
Silurian
Birkenia was a tiny jawless fish that swam in ancient Silurian seas about 430 million years ago! At only 10 cm (4 inches) long, this small but important fish was an anaspid—one of the early vertebrates that...
February 2, 2026
Devonian
Tiktaalik is one of the most important fossils ever discovered—a 375-million-year-old "fishapod" that shows the transition from fish to land animals! Found in the Canadian Arctic in 2004,...
February 2, 2026
Neogene
Phorusrhacos was one of the most terrifying "terror birds"—giant flightless predatory birds that ruled South America for millions of years! Standing 2.5 meters (8 feet) tall with a massive hooked beak, this apex...
February 2, 2026
Quaternary
Smilodon, the famous "saber-toothed cat," was one of the most iconic predators of the Ice Age! Living from about 2.5 million to 10,000 years ago, this powerful cat had enormous canine teeth that could...
February 2, 2026
Quaternary
The Woolly Rhinoceros was a massive, shaggy beast that roamed the frozen steppes of Ice Age Europe and Asia! Living from about 350,000 to 10,000 years ago, this incredible animal was perfectly...
February 2, 2026
Permian
Gorgonops was one of the most fearsome predators of the Late Permian period, approximately 260-252 million years ago! Named after the Gorgons of Greek mythology (monsters with snakes for hair), this...
The Ordovician-Silurian extinction, around 445 million years ago, was caused by a rapid ice age and fluctuating sea levels, eliminating nearly 85% of marine species.
While many famous dinosaurs were enormous, the smallest known dinosaur was the Compsognathus, only about the size of a chicken!
During the Carboniferous period, oxygen levels reached 35% (vs 21% today). This allowed insects to grow huge—millipedes reached 2.5 meters (8 feet) long!
The Permian-Triassic extinction event, known as "The Great Dying," wiped out about 95% of marine species and 70% of land species.
Megalosaurus was the first dinosaur ever scientifically named, by William Buckland in 1824. The word "dinosaur" itself wasn't invented until 1842 by Richard Owen!
T-Rex could bite with a force of up to 57,000 Newtons—like having a medium-sized elephant sit on you! This is the strongest bite force of any land animal that ever lived.
The K-Pg extinction, caused by an asteroid impact 66 million years ago, wiped out 75% of species, including non-avian dinosaurs, due to climate shifts, wildfires, and tsunamis.
Smilodon, the famous saber-toothed cat, had 28 cm (11-inch) fangs and lived throughout North and South America. Over 1,200 specimens have been found in the La Brea Tar Pits alone!
About 2.4 billion years ago, the "Great Oxidation Event" dramatically increased Earth's oxygen levels, making complex life possible.
Ankylosaurus had a tail club that could swing with 7,000-8,000 Newtons of force—enough to shatter bones, even a T-Rex's! The club was made of fused bone and could weigh over 20 kg.
Modern birds are actually living theropod dinosaurs, having evolved from a group of dinosaurs called maniraptors.
Ornithomimus and Gallimimus were the speed champions, reaching up to 70 km/h (43 mph)—faster than a horse! Their ostrich-like build was perfect for running.
Despite their tiny appearance, T-Rex arms were incredibly strong—each could lift about 200 kg (440 lbs)! Scientists think they helped grip prey or push up from the ground.
Argentinosaurus may have weighed up to 100 tons—as heavy as 14 elephants! Its thigh bone alone was taller than an adult human.
When dinosaurs roamed Earth, days were shorter! The Moon's gravity is slowly slowing Earth's rotation. 200 million years ago, a year had about 385 days.
In 2005, scientist Mary Schweitzer discovered soft tissue, including flexible blood vessels, inside a 68-million-year-old T-Rex bone—a discovery that shocked the scientific world.
Scientists diagnosed a 76-million-year-old Centrosaurus with bone cancer (osteosarcoma)—the same cancer that affects humans today! This shows cancer has been around for millions of years.
SUE is the largest and most complete T-Rex ever found—90% of the skeleton! The Field Museum paid $8.4 million for SUE in 1997, the most ever paid for a fossil at auction.
The oldest creatures preserved in amber are 230 million years old! These tiny mites from Italy are 100 million years older than any other amber fossils, perfectly frozen in tree resin.
The Hangenberg event, about 359 million years ago, was a mass extinction at the Devonian-Carboniferous boundary, caused by global cooling and anoxic oceans, wiping out many marine species.
Hadrosaurs had the most complex teeth ever—up to 300 teeth per jaw arranged in "dental batteries." These constantly replaced themselves and could grind the toughest plants.
Spinosaurus had a paddle-like tail and dense bones for buoyancy—it was semi-aquatic! This 15-meter predator hunted fish in rivers like a giant crocodile-dinosaur hybrid.
The coelacanth was thought extinct for 65 million years—until one was caught in 1938! Called a "living fossil," it has barely changed in 400 million years and was like finding a living dinosaur.
Sharks have been swimming in Earth's oceans for about 450 million years—that's 100 million years before the first trees appeared! They survived all five mass extinctions.