Horses Started Dog-Sized
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.
Discover the fascinating creatures that once roamed our planet
Cretaceous
Spinosaurus, meaning "spine lizard," was the largest carnivorous dinosaur ever known—even bigger than T. rex! Living approximately 100 to 94 million years ago during the Late Cretaceous ...
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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
Nanotyrannus, meaning "dwarf tyrant," is one of paleontology's most debated dinosaurs. This smaller tyrannosaur lived approximately 67 million years ago during the Late Cretaceous period ...
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April 17, 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 17, 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 17, 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 17, 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 17, 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 17, 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 17, 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 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.
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.
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.
While many famous dinosaurs were enormous, the smallest known dinosaur was the Compsognathus, only about the size of a chicken!
Woolly mammoths were still alive when the Egyptian pyramids were built! The last mammoths survived on Wrangel Island until about 1650 BCE—over 1,000 years after the Great Pyramid.
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.
Scientists believe dinosaurs made closed-mouth sounds like cooing, booming, or growling—similar to crocodiles and ostriches today—not the dramatic roars from Jurassic Park!
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!
Trackway evidence proves many dinosaurs traveled in herds! Parallel footprints in Texas and Colorado show sauropods moving together, and the "Dinosaur Freeway" in Colorado stretches 40 miles.
By studying fossilized melanosomes (pigment cells), scientists discovered some dinosaurs had bright colors! Sinosauropteryx had a striped tail like a raccoon.
Tiktaalik, living 375 million years ago, was one of the first vertebrates to venture onto land, with primitive lungs and leg-like fins.
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.
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!
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.
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!
Dinosaur fossils have been found on all seven continents, including Antarctica! When dinosaurs lived, Antarctica was much warmer and connected to other landmasses.
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.
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 flowering plants appeared around 130 million years ago, during the Cretaceous period, revolutionizing plant evolution.
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.
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.
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.
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.