Dinosaurs. The very word conjures images of colossal beasts, fearsome predators, and a lost world. You’ve got questions, we’ve got answers! From the bone-shaking roar of the Tyrannosaurus Rex to the peculiar appearance of the Nothronychus, the world of dinosaurs is packed with intrigue.
Fortunately, palaeontologists have dedicated their lives to uncovering the secrets of these magnificent reptiles that dominated Earth for an astonishing 164 million years, from approximately 230 to 66 million years ago. They’ve unearthed a treasure trove of information, from the cataclysmic event that led to their extinction to surprising revelations about their appearance (feathers and all!).
Below, we’ve gathered everything you need to know about dinosaurs, straight from our top experts. You’ll also discover the latest dino discoveries, including the recent identification of Scottish fossils as Scleromochlus, a flightless, cat-sized ancestor to the winged pterosaurs.
Want to dig even deeper? Be sure to explore our in-depth guides on the iconic Stegosaurus, the mighty Triceratops, and the scary truth about Velociraptors. Spoiler alert: Jurassic Park got a lot wrong!
The Latest Dinosaur Discoveries and News
With their famously tiny arm spans, we can only imagine the struggle a T. Rex might have faced with a back itch. Interestingly, a recently discovered dinosaur may have shared this curious plight. Its fossils suggest an 11-meter-long, four-tonne skeleton boasting two disproportionately small forelimbs.
This newly named dinosaur, Meraxes gigas, became extinct some 20 million years before the T. Rex. While very distantly related, these two species independently evolved their tiny arms, suggesting a survival advantage. The exact advantage remains a mystery to researchers, but some theorize these diminutive limbs could have aided non-predatory activities, such as supporting movement or holding during mating.
How Dinosaurs Rose to Dominance
Elsewhere, scientists have also uncovered how dinosaurs initially came to dominate Earth. New evidence, based on recent excavations in northwest China’s remote Junggar Basin, suggests that freezing temperatures caused by repeated volcanic winters may have been the key to the dinosaurs’ early success.
How so? The warm blood and feathery insulation of these early dinosaurs may have helped them survive the cold that decimated the planet’s other dominant reptiles. As Dr. Dennis Kent, a geologist at Lamont-Doherty and study co-author, explained, “Severe wintry episodes during volcanic eruptions may have brought freezing temperatures to the tropics, which is where many of the extinctions of big, naked, unfeathered vertebrates seem to have occurred.” He added, “Whereas our fine feathered friends acclimated to colder temperatures in higher latitudes did OK.”
What Killed the Dinosaurs? When Did They Go Extinct?
The prevailing scientific theory is that dinosaurs were wiped out by an asteroid impact. While some scientists previously theorized volcanic activity, research now points to a massive impact off the coast of modern-day Mexico approximately 66 million years ago.
The Chicxulub Impact
Just how big was the asteroid that ended the dinosaurs’ reign? The impact left behind the Chicxulub crater off Mexico’s Yucatan Peninsula, measuring an astounding 150km across and 20km deep. This catastrophic event is believed to have triggered tsunamis, earthquakes, and widespread volcanic eruptions, leading not only to the demise of the dinosaurs but to the extinction of almost three-quarters of all plant and animal life on Earth.
After blasting into the Earth, scientists believe the asteroid released immense quantities of particles and gases, blocking out the sun and causing a prolonged winter. While this caused the extinction of many dinosaur species, many species that later evolved into birds remarkably survived. A 2021 Harvard University study even suggested that the Chicxulub comet may have originated from the Oort cloud, an extended shell of icy debris at the edge of our Solar System.
When Did Dinosaurs Live?
Most dinosaurs lived during the Mesozoic Era, a period roughly spanning 245 to 66 million years ago. Scientists generally divide this era into three distinct periods:
- Triassic Period (252 to 201 million years ago): This era marked the first evolution of reptiles into the creatures we recognize as dinosaurs. Earth at this time was dramatically different, with almost all animal life concentrated on a single, extremely hot and dry landmass called Pangaea.
- Jurassic Period (201 to 145 million years ago): During this period, global temperatures decreased, leading to more water, abundant plant life, and a boom in dinosaur populations. Iconic species like the Brachiosaurus first emerged during this time.
- Cretaceous Period (145 to 66 million years ago): As continents began to drift apart, more dinosaur species evolved independently, leading to greater diversity. Despite popular culture portrayals (looking at you, Jeff Goldblum!), the Tyrannosaurus Rex and Velociraptor actually first appeared in this period, not the Jurassic.
What Was the Biggest Dinosaur Ever?
With a staggering length of 30 to 40 meters, the Argentinosaurus holds the title for the world’s largest dinosaur. It may have weighed up to an astonishing 80 tonnes, equivalent to approximately 53 adult hippos or 20,000 cats. Imagine that fight!
However, it’s worth noting that even larger animals exist today, with the blue whale weighing in at a colossal 150 tonnes.
Why Were Dinosaurs So Big?
While the exact reasons for their gargantuan size aren’t fully understood, especially concerning why they survived the end-Triassic extinction while crocodiles were nearly wiped out, we do know that during the subsequent Jurassic Period, dinosaurs diversified and grew significantly larger.
The sauropod dinosaurs like Brontosaurus, Diplodocus, and Brachiosaurus were the true heavyweights of their time. These were the largest land animals to ever live, with some exceeding 80 tonnes – more than the take-off weight of a Boeing 737. Professor Steve Brusatte notes that their ultra-efficient lungs were likely a key factor. These bird-style lungs, connected to air sacs, stored extra oxygen-rich air, allowing these dinosaurs to absorb more oxygen per breath than mammals like us.
Dinosaurs evolved in the Triassic, around 252 million years ago, following Earth’s most severe mass extinction. Massive volcanic eruptions in Siberia caused runaway global warming, killing up to 95% of all species. Among the survivors were small, cat-sized, fast-running reptiles. These dinosauromorphs were the ancestors of dinosaurs. Around 230 million years ago, they gave rise to true dinosaurs, distinguished by their upright legs fitting into a window-like opening in the pelvis, attached to the backbone by extra vertebrae. These features allowed early dinosaurs like Eoraptor and Herrerasaurus to run faster, cover greater distances, and expend less energy than most other animals of the time.
These first dinosaurs diversified into the three fundamental divisions of the dinosaur family tree: the carnivorous theropods, long-necked sauropods, and beaked, plant-munching ornithischians.
What Came Before Dinosaurs?
No, not aliens! The answer to what dinosaurs evolved from is simple: smaller reptiles. These were known as dinosauromorphs, flourishing around 242 to 244 million years ago and typically the size of a house cat. They weren’t at the top of the food chain but were speedy enough to outpace most attackers.
How Did the Earliest Dinosaurs Beat Their Rivals?
The first dinosaurs didn’t immediately dominate the world. It took them over 30 million years to assert their supremacy. They evolved on a very different Earth, with all land joined into the supercontinent Pangea, stretching from pole to pole. Early crocodiles and their relatives were the main competitors, initially outcompeting dinosaurs in species count, body size, diet, and geographical range across Pangea.
However, just as it seemed the crocodiles would prevail, Pangea began to split around 200 million years ago. Volcanic eruptions spewed greenhouse gases, leading to global warming and another mass extinction. The crocodiles were decimated, but the dinosaurs survived almost unscathed, paving the way for their subsequent dominance.
How Successful Were the Dinosaurs?
By every objective measure, dinosaurs were incredibly successful. For much of the Mesozoic Era, they dominated land ecosystems, inhabiting every conceivable environment from the poles to the equator, and from seashores to river valleys and deep mountains.
They diversified into thousands of species, ranging from feisty carnivores like Microraptor (about the size of a crow) to behemoth plant-eaters like Brontosaurus, with the heft of a jet airplane. Some were specialized runners, others diggers, and some even glided and flew. Many species sported armor and spikes, while others boasted endless varieties of horns and crests for display. It’s believed that many, if not all, dinosaurs were covered in some type of feather. Indeed, today’s birds evolved directly from dinosaurs, meaning that over 10,000 species continue the dinosaur legacy to the present day.
When Were Dinosaurs Discovered?
The short answer: in 1842, when British scientist Richard Owen coined the term Dinosauria, literally meaning “terrible lizard” in Greek. Owen is often credited as the first person to categorize dinosaurs as a distinct group of creatures after examining a particularly large dinosaur bone.
However, Owen was by no means the first to find dinosaur remains. For instance, many were unearthed in ancient China, but were often interpreted as dragon bones. Many historians have also noted how numerous dinosaur bones found in Europe were believed to be the remains of biblical creatures. As late as 1763, British physician Richard Brookes even believed a broken dinosaur femur was actually a fossilized giant’s testicle!
How Do We Know What Dinosaurs Looked Like?
Scientists employ clever detective work to estimate the appearance of dinosaurs. Experts can piece together their size from fossilized remains, and tiny details on each bone offer significant clues. For instance, many fossilized bones have minute scars that indicate how dinosaur muscles connected to their bones, also illuminating their movement. In recent years, palaeontologists have also utilized 3D computer modeling to test precisely how dinosaurs could have moved and, consequently, how they looked.
For a full explanation, you can read our complete guide to how we know what dinosaurs looked like.
How Did Dinosaurs Learn How to Fly?
Not all dinosaurs were enormous. One group, the paravian theropods, took an entirely different evolutionary path. Like most dinosaurs, the first paravians sported simple, hair-like feathers, likely for insulation. As paravians became smaller over time, their body feathers grew larger and denser. Then, they began to line their feathers on their arms, forming wings. Initially, these wings were too small for sustained flight and were probably used for display.
However, at some point, a threshold was crossed. The wings became large enough that, when flapped, they could provide lift and thrust, enabling these paravians to become airborne. Flight had evolved! From these flapping ancestors arose today’s birds. In other words, birds are dinosaurs! So while Triceratops, T. rex, and the other famous dinosaurs went extinct 66 million years ago, some dinosaurs continue to thrive.
Could We Bring Dinosaurs Back to Life, Like in Jurassic Park?
Sorry, Jeff Goldblum, but probably not. To achieve a full Jurassic Park scenario, you would need a source of well-preserved dinosaur DNA, something researchers have yet to find. It’s highly doubtful they ever will: DNA degrades over time, making its presence in fossils over a million years old incredibly unlikely. Considering dinosaurs went extinct 66 million years ago, there’s little hope that dinosaur life, as they say, “finds a way” back to us.
However, other extinct species – including an Australian amphibian called the gastric-brooding frog – have been ‘de-extincted’ using ancient DNA.
