The First Eyes Appeared 540 Million Years Ago
The evolution of eyes triggered an "arms race" of evolution. Trilobites were among the first creatures with complex eyes, with some having over 15,000 lenses!
Discover the fascinating creatures that once roamed our planet
Jurassic
Stegosaurus ungulatus is a distinct species of the famous plated dinosaur that lived during the Late Jurassic period, approximately 155 to 150 million years ago in what is now North America. ...
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Cretaceous
Therizinosaurus, meaning "scythe lizard," is one of the weirdest dinosaurs ever discovered! Despite having terrifying 1-meter-long claws (the longest of any animal ever!), this bizarre creature was ...
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Cretaceous
Mosasaurus was one of the most fearsome predators to ever rule the oceans—a giant marine reptile that dominated the seas during ...
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April 8, 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 8, 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 8, 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 8, 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 8, 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 8, 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 8, 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 evolution of eyes triggered an "arms race" of evolution. Trilobites were among the first creatures with complex eyes, with some having over 15,000 lenses!
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.
The first horses (Eohippus) were only 30 cm tall—about the size of a fox! They had four toes and lived 55 million years ago. Horse evolution is one of the best-documented in paleontology.
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.
Megalodon's teeth could reach 7.5 inches (19 cm)—three times larger than great white shark teeth! This 20+ meter shark had the strongest bite of any animal ever: 182,000 Newtons.
Stegosaurus and T-Rex never met—they lived 80 million years apart! In fact, we are closer in time to T-Rex than T-Rex was to Stegosaurus.
Argentinosaurus may have weighed up to 100 tons—as heavy as 14 elephants! Its thigh bone alone was taller than an adult human.
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 earliest evidence of herd behavior dates to 193 million years ago! Over 100 Mussaurus eggs and 80 skeletons were found together in Patagonia, showing complex social behavior.
Even the largest dinosaurs laid relatively small eggs—about the size of a football. If eggs were bigger, the shells would be too thick for babies to break out!
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 blue whale is the largest animal EVER—bigger than any dinosaur! At 200 tons, it weighs twice as much as the largest dinosaurs. Some dinosaurs were longer, but none were heavier.
Dinosaur fossils have been found on all seven continents, including Antarctica! When dinosaurs lived, Antarctica was much warmer and connected to other landmasses.
About 335 million years ago, all continents were joined into one supercontinent called Pangaea. You could have walked from Antarctica to the Arctic!
Quetzalcoatlus had a wingspan of 10-11 meters—longer than a school bus! This pterosaur was as tall as a giraffe when standing and could fly at 80 mph for days.
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.
Dinosaur fossils have been found in Alaska and Antarctica! These polar dinosaurs survived months of darkness and near-freezing temperatures, possibly having feathers for warmth.
T-Rex and Triceratops actually lived at the same time and place! The Hell Creek Formation contains both—Triceratops makes up 40% of fossils there, T-Rex 24%. They definitely encountered each other.
Supersaurus may be the longest dinosaur ever at up to 42 meters (138 feet)—longer than three school buses! Its neck alone was over 15 meters, and its tail stretched 18+ meters.
During the Cretaceous, sea levels were 150-200 meters higher than today. About 30% of today's land was underwater, and there was no ice at the poles!
About 2.4 billion years ago, the "Great Oxidation Event" dramatically increased Earth's oxygen levels, making complex life possible.
The Chicxulub crater in Mexico is 200 km (124 miles) wide—created by an asteroid 10-15 km across traveling at 20 km/second. The impact released energy equal to 4.5 billion atomic bombs!
Therizinosaurus had the longest claws of any animal ever—up to 1 meter (3.3 feet) long! Despite looking terrifying, this dinosaur was likely a plant-eater that used its claws for grabbing vegetation.