The woolly mammoth and the Tyrannosaurus rex were two of the largest animals to ever walk the Earth. Both reached enormous sizes and dominated their prehistoric environments. But when it comes to woolly mammoth vs T. rex size, which massive creature came out on top?
If you’re short on time, here’s a quick answer to your question: the woolly mammoth was larger and heavier than the T. rex. An adult male woolly mammoth could reach shoulder heights over 3.5 meters (11.5 feet) and weigh up to 6 tons.
T. rex grew up to 12 meters (40 feet) long and weighed about 6 to 9 tons at maximum size.
In this article, we will take an in-depth look at woolly mammoth and T. rex sizes. We will examine their average dimensions, maximum confirmed sizes, weight estimates, and other key size metrics. We will also overview their anatomy and behavior to provide context on how these giant creatures lived and why size mattered.
With plenty of facts, size comparisons, and analysis, you’ll learn which titan truly deserves the crown for largest land animal of its time.
Average Sizes of Woolly Mammoth and T. Rex
Typical Woolly Mammoth Dimensions
Woolly mammoths were truly giants of the Ice Age. On average, these impressive prehistoric pachyderms stood around 10-11 feet (3-3.5 meters) tall at the shoulder and weighed around 6 tons (5,443 kilograms).
The largest individuals could reach up to 13 feet (4 meters) tall and tip the scales at over 8 tons (7,257 kg) – about the size of a female African elephant!
In terms of body length, woolly mammoths measured from 20-26 feet (6-8 meters) from head to tail. Their massive curved tusks spanned 15 feet (4.5 meters) in the largest specimens. To put that into perspective, that’s longer than a mid-size sedan!
Here are some other vital statistics of these Ice Age behemoths:
- Shoulder Height: 10-11 feet (3-3.5 meters) on average
- Body Length: 20-26 feet (6-8 meters)
- Weight: 6 tons (5,443 kg) on average, up to 8 tons (7,257 kg)
- Tusk Length: Up to 15 feet (4.5 meters)
As these measurements illustrate, woolly mammoths were massively built animals adapted to the harsh ice age environment. Their large size helped them conserve heat, while their curved tusks could sweep away snow to access food.
Typical T. Rex Dimensions
In its own time, Tyrannosaurus rex was one of the largest predators to ever walk the Earth. While not quite the size of its impact in pop culture lore, T. rex still could reach staggering proportions.
On average, T. rex grew to be about 40 feet (12 meters) long from snout to tail. They stood about 12-13 feet (3.6-4 meters) tall at the hip. In terms of weight, most experts estimate adult T. rex specimens tipped the scales between 7 and 9 tons (6,350 – 8,160 kg).
Here are typical size statistics for Tyrannosaurus rex:
- Length: Approximately 40 feet (12 meters)
- Height: 12-13 feet (3.6-4 meters) at the hips
- Weight: 7-9 tons (6,350-8,160 kg)
- Skull Length: About 5 feet (1.5 meters)
The largest T. rex found so far is estimated to have measured 42-43 feet long and weighed nearly 9 tons. While gigantic, T. rex was still much smaller than some of the giant sauropods it preyed on, like Apatosaurus which could reach 75 feet long!
Interestingly, some studies suggest T. rex grew extremely fast during adolescence, putting on over 1,750 pounds per year during a massive growth spurt! This may have helped them quickly attain sizes large enough to compete with other giant dinosaurs.
So while woolly mammoths were larger by shoulder height, T. rex was longer from snout to tail. Both mammal and dinosaur could weigh as much as 8-9 tons fully grown, representing the apex predators of their prehistoric time periods.
When it comes to giants of the ancient world, it’s hard to top these two titans!
Maximum Confirmed Sizes of Each Species
Largest Known Woolly Mammoth Specimens
The woolly mammoth (Mammuthus primigenius) was an Ice Age mammal that roamed across northern Eurasia and North America during the Pleistocene epoch. These massive creatures could reach up to 13 feet tall at the shoulder and weigh up to 12 tons, making them larger than modern African elephants.
Some of the largest known woolly mammoth specimens include:
These giant Ice Age elephants had long curved tusks up to 16 feet in length and were well adapted to the frigid arctic environment with thick fur coats and layers of fat. While estimated sizes vary, the largest woolly mammoths were massive creatures comparable in height to modern female African Bush elephants but weighing over twice as much.
Largest T. Rex Fossils
Tyrannosaurus rex was one of the largest and most fearsome carnivores of the Cretaceous period, living between 68-66 million years ago. Some of the biggest T. rex fossils ever found include:
While exact sizes vary by estimate, the largest T. rex specimens reached lengths over 40 feet and weighed 8-10 tons – heavier than a full grown African Bush elephant today. Their massive size and bone crushing bite made them apex predators of the Late Cretaceous.
Weight Estimates and Comparisons
Woolly Mammoth Weight
The woolly mammoth was a massive creature that lived during the Ice Age. Based on skeletal remains, researchers estimate that these giants weighed anywhere from 6 to 8 tons (5,443 to 7,257 kg). To put that in perspective, that’s about the same weight as four average-sized cars!
The largest specimens may have tipped the scales at a whopping 10 tons.
These weight estimates are for male mammoths. Females were quite a bit smaller, weighing around 4 to 6 tons (3,629 to 5,443 kg). Still huge by modern standards, but lighter than their male counterparts.
Scientists determine mammoth weights by carefully analyzing fossilized bones and making comparisons to modern elephants. Factors like the size, shape and density of bones provide clues about the mammoth’s overall body mass.
T. Rex Weight
The fearsome Tyrannosaurus rex is estimated to have weighed between 6 and 9 tons (5,443 to 8,165 kg). Like woolly mammoths, exact weight estimates vary from specimen to specimen.
The largest T. rex specimens likely tipped the scales at over 9 tons. However, most adult T. rex fossils indicate weights between 7-8 tons. The Field Museum in Chicago has a massive T. rex skeleton named Sue that is estimated to have weighed about 8.4 tons when alive.
As with mammoths, paleontologists determine T. rex weight estimates primarily from the size and sturdiness of fossilized bones. Certain bones like the femur and vertebrae provide key insights into the overall body mass.
Weight Comparison
Both woolly mammoths and Tyrannosaurus rex were massively heavy creatures, weighing in at an impressive 6 to 9+ tons each. On average, most mammoth and T. rex size estimates fall in the 7 to 8 ton range.
While there is some overlap, woolly mammoths do appear to have the edge in terms of sheer bulk and body mass. The heaviest known mammoth specimens may have weighed up to 10-11 tons, while the top estimates for T. rex max out around 9-10 tons.
| Creature | Average Weight Range | Record Weights |
|---|---|---|
| Woolly Mammoth | 7 – 8 tons | 10 – 11 tons |
| T. rex | 7 – 8 tons | 9 – 10 tons |
So while these Cretaceous carnivores were certainly massive, the Ice Age behemoths appear to have been even heavier on average. Both creatures were giants during their respective time periods!
Role of Size in Behavior and Habitats
Why Woolly Mammoths Grew So Large
Woolly mammoths were massive Ice Age creatures that grew up to 13 feet tall at the shoulder. Their huge size likely evolved for several reasons:
- Insulation – The woolly mammoth’s thick, shaggy coat helped keep it warm in frigid environments. Larger bodies retain more heat.
- Fat reserves – A bulky body allowed woolly mammoths to store large fat reserves that sustained them through harsh winters when food was scarce.
- Strength – The mammoth’s imposing stature endowed great strength to dig craters in frozen ground for food and water.
- Protection – Few predators dared challenge a fully-grown woolly mammoth. Its immense size helped protect it from attacks.
In short, the woolly mammoth’s gigantic proportions equipped it with the tools needed to thrive in Pleistocene habitats. Its massive structure supported a lifestyle well-suited to extreme cold climates.
Advantages of T. Rex Size
The mighty Tyrannosaurus rex grew up to 40 feet long and weighed over 9 tons. What benefits did such awesome size confer?
- Hunting strategy – The T. rex’s colossal head and bone-crushing jaws allowed it to employ a bite-and-shake tactic to quickly take down large prey.
- Scavenging – With keen senses, T. rexes could swiftly locate carcasses to scavenge. No other animals dared compete for their finds.
- Intimidation – Few creatures challenged adult T. rexes. Their imposing size warded off would-be attackers.
- Speed – Contrary to early beliefs, analysis shows T. rex had a brisk walking speed of 2.5-5 mph despite its bulk. Size did not preclude agility.
The T. rex’s giant proportions facilitated its role as apex predator. Both hunters and scavengers benefited from strength, intimidation, and speed granted by its substantial size.
Other Size Metrics and Interesting Facts
Brain Size
The woolly mammoth had a large brain compared to its overall body size. Its brain was about the same size as modern African elephants, which weigh 6-7 times as much as mammoths did. Mammoths had highly convoluted neocortexes, suggesting they were intelligent and capable of advanced communication.
In contrast, T. rex had a very small brain for its body size. Its brain was only about the size of a dog or cat brain, despite weighing 7-8 tons.
Here are some interesting comparisons of woolly mammoth and T. rex brain sizes:
| Animal | Brain Size | Body Size |
| Woolly Mammoth | 4.5 kg | 6 tons |
| African Elephant | 4-5 kg | 6-7 tons |
| T. rex | 400 g | 6-8 tons |
The large brain size of the woolly mammoth suggests it may have had advanced social behaviors and communication abilities compared to other Pleistocene megafauna. Their big brains probably helped them survive in harsh environments.
Stomach Capacity
Woolly mammoths are estimated to have had stomach capacities of around 200-300 liters, which is huge compared to most mammals! This massive stomach allowed them to eat large quantities of grasses and sedges to sustain their massive bodies.
T. rex, being a carnivore, would have had a much smaller stomach capacity optimized for meat eating.
Here are some fun stomach size comparisons:
- Woolly mammoth stomach capacity: 200-300 liters
- African elephant stomach capacity: around 150 liters
- Cow stomach capacity: around 200 liters
- Human stomach capacity: around 1 liter
The woolly mammoth’s giant stomach and ability to digest huge amounts of fibrous plant material was key to its survival in the harsh northern environments it inhabited.
Fun Facts
Here are some interesting and fun facts about the woolly mammoth and T. rex:
- Woolly mammoths could reach shoulder heights of 3.5 meters, while T. rex could reach 4 meters tall.
- Mammoths had curved tusks up to 5 meters long, which they used for fighting, foraging, and digging in snow.
- T. rex had 60 banana-sized teeth capable of crushing bones!
- Mammoths were covered in long, dark brown fur and had small ears to minimize heat loss.
- T. rex likely had scaly skin with no feathers, unlike many earlier theropods.
- Mammoths lived in cold environments like the mammoth steppe, while T. rex inhabited warmer forested river valleys.
- The oldest woolly mammoth fossil dates to around 250,000 years ago, while the oldest T. rex fossil is around 68 million years old.
While T. rex captures the imagination as the “king of dinosaurs,” the woolly mammoth was equally impressive as the giants of the ice ages. These fascinating extinct animals continue to wow us today!
Conclusion
In the woolly mammoth vs T. rex size debate, the woolly mammoth clearly takes the top spot for the largest land animal of its time. Woolly mammoths grew taller at the shoulder than T. rex stood from head to tail, and weighed just as much or slightly more at maximum size.
Their enormous sizes aided both creatures as the dominant giants of their ecosystems.
While the T. rex was an apex predator that used its size to hunt large dinosaurs, the woolly mammoth’s size helped it conserve heat and acquire enough food to survive the harsh Ice Age environment. Understanding the sizes of these magnificent prehistoric animals provides insight into how they lived and why they dominated their worlds.
