Uncovering the evolution of history's largest dinosaurs

Air sacs and lightweight bones helped some dinosaurs grow to enormous sizes

After the Triassic extinctions, new species with birdlike anatomy evolved from smaller, early dinosaurs. This anatomy allowed for more efficient breathing and lighter skeletons, favoring the evolution of larger organisms.

Dinosaurs ranged from the size of chickens to multistory buildings

The largest known dinosaur, Argentinosaurus, was about 39 meters long and outweighed a Boeing 737. Species like Parvicursor and Epidexipteryx were less than 45 centimeters long, though the actual smallest dinosaur is likely lost to history.

View a directory of more than 300 dinosaurs

This resource details each dinosaur's taxonomy, type, diet, and habitat, from Aardonyx to Zuniceratops. More well-researched dinosaurs include information on when they were discovered alongside their size, behaviors, and other noteworthy findings.

Richard Owen coined the term ‘Dinosauria’ to group three giant reptiles

Identifying similarities in the fossils of Megalosaurus, Iguanodon, and Hylaeosaurus, Owen surmised that they were all part of a broader group of large terrestrial reptile species. The name “Dinosauria” came from combining the Greek words for “fearfully great” (deinos) and “lizard” (sauros).

Mammals thrived under the feet of dinosaurs

An explosion of fossil finds reveals that ancient mammals evolved a wide variety of adaptations allowing them to exploit the skies, rivers and underground lairs.

Civilizations of the past mistook dinosaur fossils for dead mythological creatures

Without knowledge of evolution or extinction, people believed such fossils were the bones of massive animals no one had ever seen alive, including dragons and giants. It was not until the science of paleontology and studies of extinction that these ideas were overturned definitively.

Huge tyrannosaur wore a fuzzy coat

It’s not your dad’s tyrannosaur: Yutyrannus huali, a newly discovered ancestor of Tyrannosaurus rex, was covered from head to tail in downy feathers.

T. rex didn't stomp, it walked on tiptoes like a bird

A new biomechanical study analyzing four T. rex specimens, including the famous "Sue" at Chicago's Field Museum, found the dinosaur used a "distal-first" foot strike, described as landing on its toes before its heel, similar to a modern ostrich. The technique improved stride efficiency and shock absorption, letting adults reach speeds up to 14 mph, while younger, lighter T. rexes could sprint closer to 25 mph.

Fossilized bite marks suggest some dinosaurs may have engaged in cannibalism

An excavation site near the Colorado-Utah border contained Allosaurus bones with tooth marks of other Allosaurus, which may have occurred in response to a dry season in the area. The Tyrannosaurus and Majungasaurus have also been shown to eat their own.

T. rex needed the same amount of calories as 80 people every day

Tyrannosaurus rex is the most extensively studied fossil creature ever known. Every year, new research is added to the towering list of papers that try to draw …

Millions of years of evolution produced dinosaurs with bizarre features

This list of the 17 weirdest dinosaurs includes a cross between a parrot and a porcupine, a dinosaur whose arms each ended with one finger, a vampire dinosaur, a dinosaur with wings on its legs instead of its arms, and a Harry Potter-inspired “dragon king of Hogwarts.”

Without dinosaurs, plants could produce fleshy fruits with bigger seeds

Previously disturbed by massive herbivores, denser and darker forests shifted plant evolution, reaching the greatest diversity of seed sizes, fruit sizes, and fruit types about 50 million years ago.

The archaeological discovery that shifted scientists' understanding of human evolution

In 2003, archaeologists in Indonesia uncovered the remains of a 3-foot-tall skeleton that appeared to belong to a new type of human. Read this article to learn how the discovery of this 50,000-year-old skeleton upended the idea that human evolution...

How paleos dig up dinosaurs

Follow Kelsie Abrams and the dig team from the field to the lab, as they unravel mysteries from the end of the age of dinosaurs.

Spinosaurus had the weirdest dinosaur tail of all time

A new fossil of one of the most unusual dinosaurs, Spinosaurus aegyptiacus, suggests it was a swimming predator powered by a fin-like tail.

Herd behavior has been seen in 193-million-year-old dinosaur fossils

Scientists excavated eggs, juveniles, and adult remains in Patagonia, all arranged by age group. The organization into structured groups may have contributed to evolutionary success by consolidating eggs in one location to make defending them easier.

What we know about the mysterious colossal squid

The colossal squid, the world's largest invertebrate, remained hidden from human discovery until nearly a century ago. Explore the world of the enormous and mysterious creature, including its features, habitat, and scientific significance. You can even plan a visit to the Museum of New Zealand Te Papa Tongarewa and marvel at a real-life display.

How flowering plants took over the world

Flowering plants are relatively young in the evolutionary scheme of things, only arriving after the dinosaurs had already been wiped out. Their evolution has long puzzled scientists, but recent research indicates their success is due to smaller,...

The Bone Wars turned paleontology into a rivalry fraught with public scandal

Othniel Charles Marsh and Edward Drinker Cope were friends-turned-enemies competing for the glory of discovering dinosaurs. It became so intense that when Cope died, he donated his body to science to prove he had a bigger brain than Marsh.

A history of belly buttons, from dinosaurs to modern dogs

Could dinosaurs have had belly buttons, just like you and me? Some researchers believe they've found evidence the ancient reptiles had the cute scar, a common feature among placental mammals (but which is also found in many more kinds of animals). Dive into their peculiar findings with this fascinating video.

Supermountains the size of the continental US may have sparked complex life on Earth

Geological records show that the Nuna and the Transgondwanan Supermountains existed around the same time as two major jumps in species complexity on the planet: the rise of large organisms and the Cambrian explosion, respectively. Researchers believe that the erosion of these mountains deposited major nutrients into the oceans and boosted oxygen levels, both of which supported more complex species.

Explore the independent lines of evidence behind the theory of evolution

Gradual changes in organisms have been directly observed through artificial selection—humans purposely selecting organisms to breed to pass on specific traits—and in organisms with short lifespans, such as insects and microbes. Analyses of DNA and anatomical structures across different species, as well as fossil records, also reveal ancient shared ancestry consistent with natural selection.

Larger animals like giraffes, elephants, and blue whales have developed a unique defense against cancer, a phenomenon known as Peto's Paradox

What we know about aurochs, the ancestors of modern cattle

The relationship between humans and cattle is invaluable and longstanding. Evidence suggests cattle's wild, larger, and now-extinct ancestors, the aurochs, were also linked to early humans. Similarly valuable for their milk and labor power, yet significantly more threatening due to their size, aggression, and speed, auroch domestication was slow and complex. Discover new information about the fascinating ancestors of modern cows and the potential of re-introducing the species with selective breeding.

See how each of the more than two million known species relates to each other—and to common ancestors—in this zoomable tree of life.

An interesting perspective on whether (and how) brain size matters in cognitive ability

Some brains are bigger than others, but what is the relevance, if any, to brain size and intelligence? This Scientific American article explores the question and offers examples. It also visually compares frontal slices of several mammals' brains, showing that humans don't necessarily have the biggest cerebrums on the block.

Ten magnificent photos of lions

A new book of essays and images reveals the history of the big cats, elaborating on how they’ve become a vulnerable species today (and efforts to preserve them).

The animatronic shark from Steven Spielberg's 'Jaws,' the first modern blockbuster, was a complex underwater apparatus called 'Bruce.'

Explore the history, structure, and species of Australia's Great Barrier Reef with this interactive journey narrated by Sir David Attenborough.

See these 16 pieces of art evoking phobias of snakes, flying, spiders, and more. 

Some Pokémon have been named after real and fictional organisms, while some real-world species have been named after Pokémon, such as Chilicola charizard and Binburrum zapdos.

Crows are believed to have intelligence on par with a seven-year-old child and demonstrate complex behaviors, from problem-solving with tools to recognizing human faces.

After NASA's Voyager 1 captured Earth as a single pixel as it left the solar system in 1990, astronomer Carl Sagan used the image to reflect on humanity's fragility and the responsibility to protect 'the only world we've ever known.'

Read a deep dive on the 'all-purpose healing' peptide BPC-157.

In 1963, a basement renovation in Turkey revealed a passageway to a hidden, multilevel underground city that once housed as many as 20,000 people

Waves off the coast of Nazaré, Portugal, can reach over 100 feet and are caused by the area's deep underwater canyon geography

The Great Salt Lake's distinct dual coloration results from high-salinity organisms that only live in the northern portion and produce a purple protein.

Exploring the Larry Bird punch that almost changed March Madness

The concept of phantom limbs, the perception that amputated limbs are still present, dates back to a French military surgeon in the 16th century.

The American cockroach is actually from Africa, an apparent hitchhiker aboard ships carrying enslaved people, with evidence suggesting the bug may have arrived in the New World as early as the 1600s.

See how Budweiser's famous Clydesdales spend their days at Warm Springs Ranch, where roughly 70 to 80 of the beer brand's giant horses can be found at any given time.

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

Watch how algorithms can be designed to train themselves and self-improve without human input, to the point where the optimized code is too complex for programmers to understand.

Hear about the 250-year history of the United States Postal Service, complete with some of its strangest deliveries, important innovations, and the figures that made it an American institution.

See how Ebola tore through Guinea, Sierra Leone, and Liberia in 2014-2016.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

Learn how to read a prospectus, the juicy document that any company must file with the SEC before going public.

Explore chaos in this simulation of two double pendulums, where small differences in the release angles produce wildly different outcomes.

Search a massive database of over 4 decades of clues from the TV quiz show 'Jeopardy!'