One Day Was Only 22 Hours Long
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.
Discover the fascinating creatures that once roamed our planet
Paleogene
Palaeophis was a giant sea snake that lived approximately 55-50 million years ago during the Eocene epoch. This massive marine predator could grow up to 9-12 meters long—making it one ...
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Cretaceous
Siamosaurus, meaning "Siam lizard" (Siam is the old name for Thailand), was a fish-eating spinosaurid dinosaur that lived approximately 125-112 million years ago during the ...
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Cretaceous
Argentinosaurus is one of the largest animals ever to walk the Earth—a titanosaur so massive that just one of its vertebrae is taller than a human! Living approximately ...
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September 25, 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...
September 25, 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...
September 25, 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...
September 25, 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...
September 25, 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....
September 25, 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...
September 25, 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...
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.
While many famous dinosaurs were enormous, the smallest known dinosaur was the Compsognathus, only about the size of a chicken!
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.
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.
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!
Despite flying alongside dinosaurs for 150 million years, pterosaurs were NOT dinosaurs—they were flying reptiles in a completely separate group. Some had fur-like covering called pycnofibers!
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.
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!
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.
The first flowering plants appeared around 130 million years ago, during the Cretaceous period, revolutionizing plant evolution.
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.
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.
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.
Thousands of dinosaur trackways have been found on every continent! Some tracks in Colorado show dinosaurs walking together in herds, and some footprints are over a meter wide.
During the Carboniferous period, insects grew to enormous sizes due to higher oxygen levels. Dragonflies had wingspans up to 65 cm!
Early whales like Ambulocetus had legs and could walk on land, showing the remarkable transition of mammals back to marine life.
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.
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.
Scientists study fossilized dinosaur poop (coprolites) to learn what they ate! A 2024 study of 500+ coprolites showed early dinosaurs were "opportunistic" eaters—they ate everything.
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!
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.
About 2.4 billion years ago, the "Great Oxidation Event" dramatically increased Earth's oxygen levels, making complex life possible.
Argentinosaurus may have weighed up to 100 tons—as heavy as 14 elephants! Its thigh bone alone was taller than an adult human.
By studying fossilized melanosomes (pigment cells), scientists discovered some dinosaurs had bright colors! Sinosauropteryx had a striped tail like a raccoon.