What dinosaur has the smallest brain to body ratio?
Mia Horton
Updated on May 14, 2026
Stegosaurus has a reputation for having a small brain and one of the lowest-brain-to-body ratios among dinosaurs. "The brain of Stegosaurus was long thought to be the size of a walnut," said armored dinosaur expert Kenneth Carpenter, director of the USU Eastern Prehistoric Museum in Utah.
Which dinosaur had the smallest brain for its body size?
Stegosaurus: the dinosaur with the smallest brain.What was the least intelligent dinosaur?
Because of this incredibly disproportionate brain to body ratio, Stegosaurus has historically been known as the dumbest dinosaur, a fact that was seemingly backed up by a proposed “second brain” located around the animal's hip.Which dinosaur had the largest brain to body ratio?
Troodontids (formerly Saurornithoidids) were remarkable in having the largest brain-to-body size ratio of all non-avian dinosaurs, possibly making them the most intelligent dinosaurs on a level with the smartest birds.Did T. rex have a small brain?
Although the ratio of brain size to body mass was very small for T. rex, it was larger than most other dinosaurs. T. rex's brain was larger than the human brain, but the cerebrum (the part of the brain that we use to think) was tiny.Animals Brain Size - Brain to Body Mass Ratio
Which dinosaur is smartest?
Troodon had a large brain for its relatively small size and was probably among the smartest dinosaurs. Its brain is proportionally larger than those found in living reptiles, so the animal may have been as intelligent as modern birds, which are more similar in brain size.Which dinosaur had a brain the size of a walnut?
It is often said that Stegosaurus had a brain the size of a walnut - in fact it was more like the size of a lime, or a dog's brain, but still relatively small for a dinosaur that grew up to nine metres long.What size was at Rex brain?
An adult Tyrannosaurus rex had a brain that weighed approximately 1 kilogramme, about half of the size of an adult humans but that does not mean that T. rex was half as smart as we are – the size of the body and the arrangement of the functions in the brain have to be considered.Which animal has the smallest brain?
Scientists have finally located the smallest brain ever seen and it belongs to a ragworm. This cousin of the humble earthworm has neurons very similar to those in the human brain despite being only the width of a human hair.Do any animals have 2 brains?
Octopus. The octopus has 9 brains, one for each tentacle and one at the head. The main brain resides at the head while the other brains are interconnected as fused ganglia, with each brain having its own set of neurons. With more than 500 million neurons, only 30 percent of them are located at its main brain.What is the ugliest dinosaur?
The 10 Ugliest Dinosaurs
- of 10. Hippodraco. Lukas Panzarin. ...
- of 10. Isisaurus. Dmitri Bogdanov. ...
- of 10. Jeyawati. Lukas Panzarin. ...
- of 10. Masiakasaurus. Lukas Panzarin. ...
- of 10. Nigersaurus. Australian Museum. ...
- of 10. Pegomastax. Pegomastax (Tyler Keillor). ...
- of 10. Suzhousaurus. Wikimedia Commons. ...
- of 10. Tianyulong. Nobu Tamura.