Archaeornithoides is an extinct genus of dinosaur that lived during the Late Cretaceous period, around 75 million years ago. This tiny dinosaur was discovered in Mongolia.
**Discovery and Naming**
In 1965, a group of Polish and Mongolian scientists found a fossil of a small dinosaur in Bayn Dzak, Mongolia. The discovery was reported in 1983. In 1992, the dinosaur was named Archaeornithoides deinosauriscus by researchers Andrzej Elzanowski and Peter Wellnhofer.
The name Archaeornithoides comes from Ancient Greek words meaning “shaped like an ancient bird.” The specific name deinosauriscus means “little dinosaur,” highlighting its small size.
The fossil, named ZPAL MgD-II/29, consists of pieces of the skull and lower jaw of a young individual. It was found in rocks that were formed from river sand, dating to the Late Cretaceous.
**Description**
Archaeornithoides was very small. The preserved skull fragment measures only about 27 millimeters long, suggesting that the full skull would have been around 5 centimeters in length. Researchers estimated its total body length to be between 50 to 60 centimeters. This makes it one of the smallest non-bird dinosaurs ever discovered.
The dinosaur had a long snout with a large opening in the skull called the antorbital fenestra. Its mouth had at least eight small, smooth teeth.
**Classification**
Scientists believe Archaeornithoides may be closely related to birds because it has several bird-like features in its skull. However, more recent fossil discoveries showed that these features can also be found in other dinosaurs, making their relationship to birds less certain.
Some scientists suggested that Archaeornithoides might actually be a baby version of another known dinosaur called Byronosaurus, but studies have shown that even young dinosaurs have unique features that make Archaeornithoides its own species.
**Paleobiology**
Paleontologists noticed some bite marks on the fossil, suggesting that it may have been prey for a small mammal. There is even a possibility that the remains were digested by a predator before they became fossilized. This could be one of the first pieces of evidence showing that mammals in that era were eating dinosaurs.
In summary, Archaeornithoides is a small dinosaur that provides fascinating insights into the connection between dinosaurs and birds as well as the interactions between different species during the Late Cretaceous period.