Estimates say 2.5 billion total T. rexes lived on Earth

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 …

Dinosaurs emerged 245 million years ago when Earth’s continents were still conjoined

Once the supercontinent split apart, dinosaurs evolved into thousands of species as they adapted to their changing environments. All non-avian dinosaurs went extinct about 66 million years ago following an asteroid impact, while avian dinosaurs evolved into today’s birds.

T. rex hunted for prey but wasn't above scavenging rotting meat

Despite possessing a huge head full of serrated teeth the size of rail spikes, the Tyrannosaurus rex had puny, rigid arms, and scientists think it enjoyed scavenging.

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.

Dinosaur portrayals in film mistakenly limit them to only living in tropical climates

The ancient creatures have been brought to life in cinema by combining animatronics and CGI. However, creative liberties have created misconceptions about dinosaurs for audiences, including that the Tyrannosaurus rex could not see stationary prey.

Why have birds never become as large as a T. rex?

Birds are descended from dinosaurs, but none have ever reached the gigantic size of their Jurassic ancestors. Some birds in the fossil record, like the "terror birds" of South America, have reached as large as ten feet, but the energy-intensive act of flying disallows birds much larger than that. Researchers claim a lack of evolutionary pressure and predatory bird behavior likely limit bird size.

Explore an interactive timeline and map of dinosaurs across the globe

This tool maps dinosaur habitats based on fossil sites around the world. It includes short articles and additional information—including size, diet, and weight—about each dinosaur. A timeline and data table also allow users to compare dinosaur emergence and extinction dates.

Uncovering the evolution of history's largest dinosaurs

This article details how sauropods—the dinosaurs that Little Foot would call longnecks—repeatedly evolved to attain such colossal sizes, towering over other land critters, including tyrannosaurs and mammoths. Sauropods were giant, long-necked...

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.

The day the dinosaurs died

Roughly 66 million years ago, a giant meteor struck Earth off the coast of the Yucatán Peninsula. Some dinosaurs died in the immediate impact, which sent a 200-foot tsunami all the way up to what is now North Dakota. Many others perished in the resulting change in climate, with debris ejected into the global atmosphere. This 12-minute video provides an overview of what scientists have uncovered about the fateful day.

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.

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).

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.

Studies estimating the number of years between human generations suggest there have been approximately 10,000 to 12,000 generations of humans.

Research has found that the length of human generations has varied throughout the 300,000 years that Homo sapiens have been around, ranging from about 25 to 30 years. These values come from analyzing genetic mutations, since the blend of them passed onto children changes as parents age.

Fossils suggest tardigrades developed cryptobiosis more than 180 million years ago

As of 2024, three tardigrade fossils have been discovered, all preserved in amber. Analysis suggests different species of the organism existed over 500 million years ago, when marine heterotardigrades and freshwater terrestrial eutardigrades diverged. (Some readers may experience a paywall.)

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.

Ticks survived 27 years in a lab, including eight without food

Research published in 2022 set a new record for tick longevity. A group of adult African ticks that are normally found in eastern and southern Africa lived in a laboratory for 27 years, including eight without food. What's more, one of the females laid eggs at least four years after the last male died. Most ticks, on average, reportedly live for six months to three years.

View a breakdown of the identified species on Earth

Over 2 million species have been documented by scientists, but there may be as many as a billion distinct species. The vast majority of the species on Earth are insects, while mammals form the smallest group.

You're probably 2% Neanderthal

Scientists examining the evolutionary history recorded within our DNA are uncovering the global human story in greater detail. Watch the film to discover what percent Neanderthal you may be.

Rapid environmental changes are exacerbating natural extinction processes

Human activities behind climate change, habitat destruction, pollution, and overhunting have resulted in extinction rates up to 1,000 times greater than normal, triggering massive biodiversity loss. This has led scientists to refer to the current geological age as the Anthropocene era, in which humans are the dominant force shaping nature.

Radiometric dating uses radioactive isotopes to determine the age of objects

By comparing the amounts of parent and daughter isotopes and knowing how long it takes a sample of the former to become the latter, scientists can estimate when an organism was alive or when rocks formed.

The US restaurant industry generates over $1T in sales

In 2024, the industry brought in $1.1T, and the National Restaurant Association anticipated reaching $1.5T in 2025, numbers that are considered a return to normal after the tumultuous years of the COVID-19 pandemic. The industry also employs a large workforce, with over 13 million employees. (Some readers may experience a paywall.)

Explore the roughly 190 Egyptian pharaohs across 31 dynasties

The meticulous records kept by scribes in ancient Egypt allow contemporary historians the unusual ability to list the civilization's hundreds of monarchs, from the quasi-legendary Egyptian unifier Narmer (also known as Menes) all the way to the Roman emperors 3,000 years later.

European diseases killed a massive share of the Native American population

After Western contact, epidemic diseases devastated Indigenous communities. By 1920, the Native American population of the US had fallen to roughly 270,000, compared with an estimated 1.2 to 18 million at the time of European arrival.

The R0 value is how epidemiologists quantify disease contagiousness

The basic reproduction number indicates the average number of people a person with a disease will infect. Measles is the most contagious disease, with an R0 of 12-18, though vaccines have significantly reduced the number of susceptible individuals.

Earth’s major tectonic plates make up 95% of its surface

Tectonic plates are pieces of Earth’s lithosphere, which consists of the crust and the solid, upper layer of the mantle. Segments of major plates can break and form minor or microplates, whose total number varies based on ongoing geological activity.

Indefinite cloning of some endangered species may not sustain their longevity because cloning success rates decrease as genetic mutations accumulate.

View the ten deadliest tornadoes in US history.

See a 3D reconstruction of Tenochtitlan, the Aztec capital that was home to an estimated population of 200,000 to 400,000.

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

While the first exchange-traded fund (a 'basket' of different assets that can be bought and sold on a stock exchange) in the US only launched in 1993, the global ETF market has grown to more than $10T in the short time since.

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.

Neutron stars, the remains of some massive stars after they explode in a supernova, are the densest directly observable objects in the universe.

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.

Scientists have struggled to pin down Ebola's natural reservoir species for decades, but the available evidence suggests that it's very likely fruit and insect-eating bats found in Africa.

About 2,000 US babies are born annually without some portion of their limbs, potentially leading to a lifetime of pricey prosthetics.

Calculate how much of your tax dollars go to each federal program based on your income, filing status, and number of children

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

About 12.5% of US adults experience a phobia in their lifetime, a diagnosis that hinges on the intense fear interfering with daily life and persisting for at least six months.

Fast-casual restaurant Chili's is experiencing a resurgence, with its parent company recently reporting a nearly 32% increase in sales, thanks to passionate Gen Z fans on TikTok.

Track the location of the Voyager probes, currently between 13 and 15 billion miles away from Earth.

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

The distributor behind 'Rocky Horror' pulled the film from its scheduled national release, believing it would be a failure, though it eventually amassed a dedicated fanbase through midnight showings, a trend that continues over 50 years later.

The Russia-Ukraine conflict is the largest ground war in Europe since World War II in casualties, forces mobilized, and displacement of civilians.

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 US Constitution is widely regarded as the longest-standing written national constitution still in force—see how it has influenced rights worldwide.

For centuries, it was common to sleep in two shifts: a few hours at the beginning of the night, and a longer period beginning around midnight

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

Electrical grids worldwide must double their power delivery capacity by 2050 to meet surging demand from AI and electric vehicles.

In its famous catalog, Sears sold $600 DIY house kits from 1908 through the 1940s, resulting in an estimated 100,000 'Sears and Roebuck homes.'