Isauros

Isauros refers to a genus of small, bipedal theropod dinosaurs that lived during the Late Jurassic period, approximately 155 to 150 million years ago. Fossils of this dinosaur have been discovered primarily in the Upper Jurassic strata of Portugal, specifically in the Lourinhã Formation, which is renowned for its well-preserved dinosaur remains.

Isauros is classified within the family Compsognathidae, a group of small, lightweight theropods closely related to modern birds. The genus was first described in 2006 by Portuguese paleontologists, though its fossils had been known since the 1990s. The name *Isaurus* is derived from the ancient region of Lycia in modern-day Turkey, where the related genus *Compsognathus* was discovered, reflecting the taxonomic connection between the two.

Isauros is known from a single species, *Isaurus catonianus*, named after the nearby village of Canto da Maia. The holotype specimen consists of a nearly complete skeleton, including a well-preserved skull, which has provided valuable insights into the anatomy of this dinosaur. Estimates suggest that *Isaurus* measured around 1 to 1.5 meters (3.3 to 4.9 feet) in length and weighed approximately 1 to 2 kilograms (2.2 to 4.4 pounds), making it one of the smaller theropods of its time.

Like other compsognathids, Isauros likely had a diet consisting of small vertebrates, insects, or other invertebrates. Its slender build and sharp teeth indicate a predatory lifestyle, though it may not have been as aggressive as larger theropods. The discovery of Isauros contributes to the understanding of the diversity and evolution of small theropods during the Late Jurassic, particularly in Europe.

The Lourinhã Formation, where Isauros fossils were found, also yields remains of other dinosaurs, such as *Lourinhanosaurus* and *Dilophosaurus*, highlighting the region's significance in paleontological research. Ongoing studies continue to refine the taxonomy and ecological role of Isauros within its prehistoric environment.