Tiny Mammals Lived With Dinosaurs
Small mammals existed for over 160 million years alongside dinosaurs! They were mostly nocturnal and mouse-sized, waiting in the shadows until the dinosaurs went extinct.
Discover the fascinating creatures that once roamed our planet
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 ...
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Jurassic
Dilophosaurus, meaning "two-crested lizard," was one of the largest predators of the Early Jurassic period, living approximately 193 million years ago. Famous for its distinctive paired head crests, ...
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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 ...
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May 15, 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...
May 15, 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...
May 15, 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...
May 15, 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...
May 15, 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....
May 15, 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...
May 15, 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...
Small mammals existed for over 160 million years alongside dinosaurs! They were mostly nocturnal and mouse-sized, waiting in the shadows until the dinosaurs went extinct.
During the Carboniferous period, insects grew to enormous sizes due to higher oxygen levels. Dragonflies had wingspans up to 65 cm!
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!
Crocodilians have existed for over 200 million years, surviving the asteroid that killed the dinosaurs. They've barely changed because their design is nearly perfect for their lifestyle.
Around 700 million years ago, Earth was almost completely covered in ice during the "Snowball Earth" period, with temperatures as low as -50°C.
By studying fossilized melanosomes (pigment cells), scientists discovered some dinosaurs had bright colors! Sinosauropteryx had a striped tail like a raccoon.
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.
Horseshoe crabs have remained virtually unchanged for 450 million years—they existed before dinosaurs, survived all mass extinctions, and still live today! They're older than trees and sharks.
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!
Fossils show dinosaurs brooding their eggs like birds! A 70-million-year-old Oviraptor was found sitting on a nest of 24 eggs, proving dinosaurs were devoted parents who cared for their young.
Tiktaalik, living 375 million years ago, was one of the first vertebrates to venture onto land, with primitive lungs and leg-like fins.
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.
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.
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.
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.
A T-Rex and Triceratops were found fossilized together, possibly killed while fighting! The Triceratops has a T-Rex tooth embedded in its body—evidence of a real prehistoric battle.
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.
About 2.4 billion years ago, the "Great Oxidation Event" dramatically increased Earth's oxygen levels, making complex life possible.
Modern birds are actually living theropod dinosaurs, having evolved from a group of dinosaurs called maniraptors.
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.
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.
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.
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.