Atacamatitan is a type of dinosaur that lived during the Late Cretaceous period, around 100 to 68 million years ago. Its name means “Atacama Desert titan,” named after the location in Chile where its remains were found.
**Discovery**
In February 2000, researchers from Chile and Brazil set out to find fossils in Chile. During their expedition, they discovered the Tolar Formation, which is about 150 kilometers north of Calama. In July 2001, they returned for a second expedition and began to excavate the area.
They found a set of bones known as the holotype, labeled SGO-PV-961. This fossil was discovered in an area of 2 square meters near Conchi Viejo in the Atacama Desert. Atacamatitan is thought to belong to the Late Cretaceous period because of the way the fossils were found.
In 2011, paleontologist Alexander Kellner described and named Atacamatitan. The specific name “chilensis” refers to Chile, which is where the dinosaur was discovered.
**Description**
The holotype of Atacamatitan includes parts of its bones, such as a right femur (thigh bone), a humerus (upper arm bone), several vertebrae (bones in the back), ribs, and some other fragments. These bones were found to be quite heavy due to a process called permineralization.
Atacamatitan is estimated to have weighed between 8,000 and 16,000 kilograms, making it a large dinosaur. Its bones have some unique features that help identify it as different from other similar dinosaurs.
For example, the vertebrae of Atacamatitan have smooth shapes that aren’t seen in many other titanosaurs. Its femur indicates that it had strong legs, suggesting it was well-built.
**Classification**
Atacamatitan belongs to a group of dinosaurs called Titanosauridae. This group is known for its large, plant-eating dinosaur species. However, because the bones found are only partially complete, scientists have a hard time placing Atacamatitan in a specific family of dinosaurs.
In a study from 2012, scientists included Atacamatitan in a group of related dinosaurs called Lithostrotia, showing that it’s part of a larger family of gigantic dinosaurs.
In short, Atacamatitan is an important discovery in dinosaur history, helping scientists learn more about the diverse dinosaurs that once roamed the Earth.