Byronosaurus

Name Origin

Byron Jaffe's Lizard (Named after an expedition supporter)

Family

Troodontidae

Classification

Diapsida, Saurischia, Theropoda

Habitat (Discovery Location)

Mongolia

Period

Late Cretaceous

Length

Approximately 1.5 meters

Weight

Approximately 4–5 kg

Diet

Carnivore (Meat-eater)

Description

When thinking of carnivorous dinosaurs, one usually imagines “serrated, knife-like teeth.” However, a small dinosaur that defies this convention lived in Mongolia.
Its name is “Byronosaurus.”

Inhabiting the Gobi Desert during the Late Cretaceous, this troodontid is known for the discovery of exceptionally well-preserved skulls, which are considered a key to unraveling the evolution of birds.

A Hound-like Face and “Needle-like” Teeth

The greatest characteristic of Byronosaurus lies in its unique head structure, which sets it apart from other dinosaurs in the Troodontidae family.

Why No Serrations?

Typical troodontid teeth are thick and have serrations (jagged edges) on the sides for slicing meat.
However, the teeth of Byronosaurus were small, thin, and needle-like, with absolutely no serrations.
This is a very rare feature for a carnivorous dinosaur.

A Long Snout to Protect the Eyes

Additionally, its snout was elongated like that of a hound.
It is believed that this long snout played a role in protecting its eyes by keeping them at a safe distance from counterattacks when captured prey struggled.

What Did This Slender 4kg Hunter Eat?

Their bodies were extremely lightweight.
While the total length was about 1.5 meters, the hip height when standing was only about 43 to 50 cm.
As for weight, it was merely 4 to 5 kg.

Targeting “Soft” Small Animals

Given this slender build and “weak teeth” unsuited for slicing meat, they likely did not attack large prey.
Their presumed main prey were small animals with bodies that were not very hard.

Small birds and mammals
Lizards and frogs
Insects

Their needle-like teeth were specialized for catching these agile small creatures and ensuring they did not escape.

Top-Level Preservation! What Fossils Tell Us About the Resemblance to “Birds”

Byronosaurus also surprised paleontologists with the high quality of its fossils.

The Most Beautiful Skull Among Troodontids

The first fossil was found in 1993, followed by another discovery in 1996 in the Gobi Desert.
So far, fossils of adults including two skulls have been found. One of them (about 23 cm long) is known as the best-preserved skull among all troodontids discovered to date.

Detailed study of this specimen revealed many similarities between Byronosaurus and birds.
They convey the evolutionary process from small dinosaur to bird to the present day through these clear fossil records.