Paleontologists from the Natural History Museum in London have identified a new dinosaur species, *Enigmacursor mollyborthwickae*. It lived in North America during the Late Jurassic period, approximately 150 million years ago.
This herbivorous dinosaur was similar in size to a Labrador retriever. It had long legs, allowing it to move quickly and escape larger predators.
Fossils of *Enigmacursor mollyborthwickae* were found between 2021 and 2022 in the Morrison Formation, a geological region in the western United States. This area is known for its abundant fossil record of Late Jurassic dinosaurs. Although many bones were unearthed, the skull and parts of the spine were missing, leaving scientists uncertain about its exact length.
The name *Enigmacursor* comes from the Latin words "enigma" and "cursor," meaning "mystery" and "runner," respectively. This reflects the enigmatic nature of this dinosaur and its ability to move rapidly. The species was named in honor of Molly Borthwick, whose donation enabled the acquisition and display of the skeleton at the Natural History Museum in London.
This discovery provides valuable information about the diversity of small dinosaurs that inhabited North America during the Late Jurassic. For a long time, paleontologists focused on larger dinosaurs. Findings like *Enigmacursor mollyborthwickae* highlight the importance of studying smaller species to better understand the ecology and evolution of these prehistoric animals.
The discovery also underlines the paleontological richness of the Morrison Formation. Further exploration and study of fossils in this region are needed to learn more about life on Earth during the Late Jurassic period. The complete study on *Enigmacursor mollyborthwickae* was published in the journal *Royal Society Open Science* on June 25, 2025.