It’s impossible to know exactly how fast dinosaurs were, but by studying their skeletons, calculating their footprint length, hip height, and stride length, and applying biomechanical principles based on living animals, we can come up with some relatively accurate estimations, says Will Newton.
As a group, the dinosaurs reigned for nearly 180 million years, from 245 to 66 million years ago, and during that time they evolved into thousands of different forms; some fast, others not so much. For those that weren’t heavily armoured, or armed - quite literally - to the teeth, speed was essential for survival.
10 fastest dinosaurs
Most of the fastest dinosaurs were small, agile, and notably bipedal, meaning they ran on two legs rather than four. But there were also several larger, less nimble species that may have been a lot faster than their typical depictions would have you believe.
Here are 10 of the fastest dinosaurs that ever lived, in no particular order…
Velociraptor (40 km/h)
It’s no surprise that the dinosaur whose name literally means ‘swift thief’ has made it onto this particular list.
Velociraptor had a lightweight frame and a long tail - traits that not only made it fast, but incredibly agile too. It used its swiftness and agility to hunt many different types of prey, including several dinosaurs that were twice its size, such as Protoceratops.
According to estimates, Velociraptor would have been capable of reaching speeds of up to 40 km/h, which is just a tad slower than Usain Bolt during his 100m-world-record-smashing prime.
This might not sound particularly fast, especially if you’re picturing the oversizedVelociraptors from Steven Spielberg’s Jurassic Park, but once you learn that a Velociraptor, in reality, was no bigger than a large turkey, a top speed of 40 km/h suddenly seems quite quick!
Deinonychus (40 km/h)
From one speedy raptor to another, Deinonychus is widely believed to be the dinosaur that inspired the oversized, cinematic portrayal of Velociraptor.
Deinonychus belongs to the same family of dinosaurs as Velociraptor, the dromaeosaurids, but it grew twice as long (~3m), twice as tall (~1m), and weighed in at roughly 70kg.
Based on studies of its skeleton, it’s estimated that Deinonychus was also capable of reaching speeds of up to 40 km/h and, like Velociraptor, was incredibly agile, able to use its long tail to balance itself as it quickly changed direction while pursuing prey.
As a result of its larger size, plus the fact that it was equipped with a pair of deadly, sickle-shaped claws on each of its second toes, Deinonychus is believed to have preyed on big dinosaurs, such as a type of iguanodon known as Tenontosaurus. It may have also hunted in packs, just like the Velociraptors from Jurassic Park.
Struthiomimus (55 km/h)
This dinosaur looks just like an ostrich, which is ultimately how it got its name Struthiomimus, or ‘ostrich-mimic’.
Struthiomimus was roughly the same size as an ostrich, standing ~2.5m tall and weighing about 150kg, but it wasn’t quite as quick. According to estimates, Struthiomimus' top speed was roughly 55 km/h, which is faster than a brown bear’s, a rhino’s, and an average dog’s, but 15 km/h slower than the fastest recorded ostrich.
Still, Struthiomimus was one of the fastest dinosaurs of its time (the Late Cretaceous, 77-66 million years ago) and likely used its swiftness to evade most would-be predators.
Struthiomimus is a theropod - a group of dinosaurs that are predominantly carnivorous and includes famous, meat-eating forms such as T.rex, Velociraptor, and Allosaurus. However, unlike these obligate carnivores, it’s thought Struthiomimus may have been an omnivore that used its large, toothless beak to pick buds and shoots from trees, as well as swallow small animals whole.
Tyrannosaurus (30 km/h)
As dinosaurs go, Tyrannosaurus - the genus that includes the most famous species of dinosaur, T.rex - wasn’t particularly fast. In fact, it may have struggled to outrun an average human at peak physical fitness.
That said, it was faster than most of the large, herbivorous dinosaurs that it preyed upon, including hadrosaurs, ceratopsians, and ankylosaurs. The ankylosaurs, in particular, were amongst the slowest dinosaurs. They ‘ran’ at speeds of just 5 km/h, so when it came to fight-or-flight encounters with Tyrannosaurus, they probably always chose to fight.
It’s unclear exactly how giant tyrannosaurids such as T.rex (~13m in length, ~4m-tall at the hips, and about 9,000kg in weight), hunted these slower, often heavily armoured dinosaurs, but it’s often said that they were ambush predators that relied on quick bursts of speed to surprise and catch inattentive prey.
Interestingly, young tyrannosaurids are thought to have been significantly quicker than their parents and, as a result, may have occupied different ecological niches and hunted smaller, nimbler prey. This theory explains how young tyrannosaurids were able to live alongside larger, stronger, and more ferocious adult tyrannosaurids while avoiding competition.
Triceratops (35 km/h)
So far, all of the dinosaurs that have made this list ran on two legs. Triceratops, a stocky, fully quadrupedal herbivore, bucks this particular trend and may just be one of the fastest dinosaurs to have run on four legs, with some palaeontologists estimating top speeds of roughly 35 km/hr.
Triceratops was built just like a rhino, but it was more than five times the size. It measured 9m in length, stood 3m tall, and weighed in at a scale-breaking 10,000kg. It’s characterised by its huge, ornate frill and the three horns on its face, which is also what gives it its name Triceratops, or ‘three-horned face’.
Triceratops lived during the Late Cretaceous (68-66 million years ago) and famously shared a habitat with T.rex. T.rex no doubt preyed upon Triceratops, but considering its size and its speed, Triceratops was by no means an easy meal.
Both Triceratops and T.rex lived long enough to witness the asteroid impact that wiped out the non-avian dinosaurs at the end of the Cretaceous. This impact not only brought an end to one of the most successful dynasties ever, but perhaps the most dramatic predator-prey rivalry of all time.
Gallimimus (56 km/h)
Like Struthiomimus and other ostrich lookalikes, Gallimimus belongs to a family of dinosaurs known as the ornithomimids. These were some of the fastest dinosaurs that ever lived and Gallimimus is widely believed to have been the fastest of the bunch, with an estimated top speed of 56 km/h.
As well as being the fastest ornithomimid, Gallimimus is also the largest, measuring 6m in length, standing twice as tall as an adult human (about 3.6m), and weighing in at nearly half a ton (around 490kg).
It’s thought that Gallimimus lived in groups and relied on safety in numbers, as well as their speed, to avoid becoming dinner. That said, Gallimimus were probably occasional prey for several relatively speedy tyrannosaurids, such as Tarbosaurus and Alioramus.
Gallimimus, like Struthiomimus, is thought to have been an opportunistic omnivore that fed on both plants and small animals. It has also been suggested that Gallimimus, and other ornithomimids, practiced filter feeding and used their beaks to strain algae, molluscs, and ostracods from waterways, just like today’s ducks do.
Dryosaurus (43 km/h)
This pint-sized iguanodont is thought to have been one of the fastest dinosaurs that lived during the Late Jurassic (155-145 million years ago), with an estimated top speed of 43 km/h.
While small for an iguanodont, Dryosaurus still reached lengths of up to 3m and may have weighed as much as 100kg when fully grown, making it around the same size as a large jaguar.
Like other speedy dinosaurs, Dryosaurus had a long, stiff tail that helped it to maintain its balance while running at top speed. Its legs were also long and slender - another sign that it was built for life in the fast lane.
Dryosaurus was a herbivore equipped with a short beak and specialised cheek teeth that it used to grind up tough plant material, such as ferns. It lived on large, expansive floodplains and shared this habitat with one of the most infamous predators of the Jurassic, Allosaurus.
Allosaurus (34 km/h)
In terms of large predatory dinosaurs, only T.rex is more famous than Allosaurus - arguably the T.rex of its day (the Late Jurassic, 155-143 million years ago).
Allosaurus was a lot smaller and more gracile than T.rex, measuring 8.5m in length, standing 3m tall at the hips, and weighing just 2.5 tons. A lighter frame likely meant that Allosaurus could have reached slightly faster speeds than T.rex, as much as 34 km/h according to some estimates.
That said, studies of Allosaurus’ skeleton have noted that its legs were not quite as well suited for high speeds as the legs of some tyrannosaurids, suggesting they may not have been quite as quick over short distances.
Allosaurus was a particularly belligerent predator that regularly took on dinosaurs more than twice its size, including members of the largest group of dinosaurs that ever lived, the sauropods. Allosaurus also had a fierce rivalry with Stegosaurus, as evidenced by the fact that a tail vertebra from an Allosaurus was once found with a partially healed puncture wound that perfectly fit the profile of a Stegosaurus’ tail spike.
Nanotyrannus (60 km/h)
There aren’t many dinosaurs that have caused quite as much controversy as Nanotyrannus. This lightly built and long-limbed tyrannosaurid is thought by many palaeontologists to represent a juvenile T.rex, but some argue that it’s a distinct species.
Whatever Nanotyrannus was, it’s clear from its lightweight, less heavyset skeleton that it was faster than T.rex and probably relied on speed, rather than size and strength, when it came to hunting prey. Those that claim Nanotyrannus is a distinct species also point to its long(ish) arms and comparatively larger claws as signs that would have hunted very differently to T.rex.
Nanotyrannus was roughly 15% of the size of T.rex, but according to several estimates is thought to have been a lot faster, perhaps capable of reaching speeds of up to 60 km/h.
A 2016 study found that Nanotyrannus had a cursorial limb proportion score (CLP) of 35.8, which is more than triple that of T.rex (11.5). In short, this higher score means that Nanotyrannus was significantly faster and more agile than T.rex. After this study was conducted, lead author Scott Persons claimed that “No dinosaur was better adapted to chase you down [than Nanotyrannus].”
Compsognathus (65 km/h)
The fastest dinosaur on this list, and perhaps the fastest dinosaur of all time, is also one of the smallest, measuring 90cm in length and weighing in at less than 1kg.
For decades, Compsognathus was known as the smallest dinosaur and it has only since been superseded by tiny, raptor-like dinosaurs such as Mahakala and Microraptor. Like these other tiny dinosaurs, Compsognathus was a carnivorous theropod that preyed on small animals, like lizards.
Despite its minute size, Compsognathus is widely considered one of the fastest dinosaurs and is estimated to have had a top speed of 65 km/h. This has been questioned by some palaeontologists, but if true it would mean that Composgnathus could match, and even outrun, some of the quickest animals alive today, including hares, greyhounds, and impalas.
Still, the fastest dinosaur is no match for the fastest extant terrestrial animal, the cheetah. This spotted cat can reach speeds of 120 km/h and accelerate from 0 to 97 km/h in less than three seconds.