Dilophosaurus, a large predatory dinosaur from the Early Jurassic period, continues to capture the imagination of many. Understanding where this ancient creature lived offers a window into Earth’s distant past, helping scientists reconstruct ancient environments and ecosystems. The study of its habitat and fossil locations provides valuable insights into our planet’s dynamic history.
Ancient Habitats and Geography
Dilophosaurus roamed the Earth during the Early Jurassic period, approximately 195.2 to 183.7 million years ago. This was a time when the supercontinent Pangea was just beginning its gradual break-up. The region inhabited by Dilophosaurus was situated on the western edge of this vast landmass, likely positioned between 30 and 40 degrees north of the equator.
The primary geographic area where Dilophosaurus lived corresponds to what is now northern Arizona in the United States. However, the geological formation where its fossils are found, the Kayenta Formation, extends across northern Arizona, southeastern Utah, western Colorado, and northwestern New Mexico. This expansive territory provided diverse landscapes for the dinosaur.
The environment Dilophosaurus inhabited was characterized by lush, forested riverine systems and expansive floodplains. These areas featured abundant water sources, with river systems flowing across relatively flat terrain. The climate was generally warm, fluctuating seasonally between wet and dry periods, creating a landscape that was both arid in some parts and rich with vegetation along waterways.
This ancient ecosystem supported a variety of life forms alongside Dilophosaurus. Other dinosaurs, such as Scutellosaurus and Sarahsaurus, shared this habitat. The Kayenta Formation’s fossil record indicates the presence of various plants, including cycads, ferns, horsetails, and conifers, as well as freshwater invertebrates, fish, amphibians, and other reptiles. This rich biodiversity formed a complex food web in which Dilophosaurus played a significant role.
Fossil Discoveries and Insights
Our knowledge of Dilophosaurus’s ancient home comes largely from fossil discoveries within the Kayenta Formation in northern Arizona. The initial findings occurred in 1940, when three skeletons were unearthed, with the two most complete specimens collected in 1942. These first discoveries were made by Jesse Williams, a Navajo man.
Paleontologist Samuel Welles was among the first to study these remains in 1942, initially classifying them under the genus Megalosaurus. It was later, in 1964, that Welles discovered a more complete specimen that clearly displayed the distinctive crests on its skull. This led him to establish the new genus Dilophosaurus in 1970, giving it the name Dilophosaurus wetherilli.
Fossil evidence from the Kayenta Formation includes not only skeletal remains but also trace fossils, such as footprints. These three-toed footprints, known as Dilophosauripus williamsi, are consistent with the expected size and shape of Dilophosaurus’s feet. Such trace fossils, along with resting traces, provide additional clues about the dinosaur’s behavior and movements across the ancient landscape.
The geological context of these finds further supports our understanding of Dilophosaurus’s environment. The Kayenta Formation itself consists of fine-grained sedimentary rocks like siltstone and sandstone, formed from deposits in river systems and floodplains. This sedimentary record, combined with the types of flora and fauna preserved alongside Dilophosaurus fossils, provides concrete evidence for the warm, humid, and river-dominated habitat described.