Stegosaurus, with its distinctive plates and tail spikes, is one of the most recognized dinosaurs. This article explores the actual size of this ancient herbivore, detailing its length, height, and weight based on scientific understanding.
Measuring Stegosaurus
Typical adult Stegosaurus measured between 21.3 to 30 feet (6.5 to 9.1 meters) in length from snout to tail. Some of the largest known individuals could reach up to 25 feet (7.5 meters) long. A particularly well-preserved specimen, nicknamed “Apex,” discovered in Colorado in 2022, was reported to be 27 feet long. The dinosaur stood approximately 9 to 14 feet (2.7 to 4 meters) high, with an overall standing height reaching 10.8 to 14.8 feet (3.3 to 4.5 meters). Weight estimates for Stegosaurus vary, generally ranging from 5,000 to 7,000 pounds (2,270 to 3,175 kilograms), or about 2.5 to 3.5 tons. Some larger specimens are estimated to have weighed over 5 metric tons (5.5 short tons), with other estimates reaching 6,800 to 8,400 pounds (3,100 to 3,800 kg). These measurements are derived from fossil records, though complete Stegosaurus skeletons are rare, with many significant finds originating from the Morrison Formation in the western United States.
Distinctive Features and Their Role in Size Perception
The large, kite-shaped bony plates that ran along Stegosaurus’s back are its most distinctive features. These plates, known as osteoderms, were arranged in a double row and were embedded in the skin rather than directly attached to the spine. While contributing to the animal’s perceived bulk, these structures were relatively thin and did not add significantly to its overall body mass. Scientists suggest the plates may have been used for display, possibly for attracting mates or species recognition, and perhaps also played a role in thermoregulation.
The tail of Stegosaurus was armed with two pairs of long, pointed spikes, informally known as thagomizers. These spikes, each measuring between 2 to 3 feet long, served as a defensive weapon. Evidence for their use includes puncture marks on an Allosaurus tail vertebra that match a Stegosaurus spike.
Stegosaurus Size in Perspective
Stegosaurus can be compared to familiar modern objects and animals to visualize its dimensions. Its length, 21 to 30 feet, is comparable to a large school bus, which is about 40 feet long. The dinosaur’s height, reaching up to 14 feet, is similar to that of a modern elephant, which stands around 10 feet tall. In terms of weight, Stegosaurus was similar in mass to a large delivery truck or a bull African elephant, which can weigh around 6 tons. Despite its substantial size, Stegosaurus was not among the largest dinosaurs; sauropods like Argentinosaurus or Brachiosaurus were considerably larger. Stegosaurus was a significant herbivore in the Late Jurassic ecosystems where it lived.