The Parasaurolophus is one of the most distinctive dinosaurs from the Late Cretaceous period, immediately recognizable by the long, backward-sweeping crest on its skull. It lived in western North America approximately 76.5 to 73 million years ago, coexisting with species like Tyrannosaurus and Triceratops. Its unique anatomy and prominent crest led to its scientific name, coined by William Parks in 1922, which clarifies the dinosaur’s biological relationships and its most famous physical trait.
The Literal Meaning of the Name
The scientific name Parasaurolophus is a compound of three Greek root words that translate directly to “Near Crested Lizard.” The name was specifically chosen because the dinosaur’s anatomy was considered similar to another crested hadrosaur, Saurolophus, but with a slightly different crest structure.
The first component, Para, means “near” or “beside,” suggesting a close but not identical relationship to the already named genus. The middle segment, Sauros, is the Greek word for “lizard.” The final part, Lophos, translates to “crest” or “helmet,” referencing the animal’s most obvious feature. Combined, “Near Crested Lizard” reflects the initial assessment of the animal as a cousin to Saurolophus. The specific species name P. tubicen, meaning “trumpeter,” further emphasizes the connection between the crest and sound.
The Role of the Distinctive Crest
The crest is a remarkable physical feature, forming a long, hollow tube made from the nasal and premaxillary bones of the skull. This bony structure extended backward from the head, sometimes reaching over a meter in length, and was filled with a complex, looping internal passage. The hollow crest and intricate tube system, running from the nostrils up to the tip and back down, suggests a function beyond mere display.
The leading scientific hypothesis regarding the crest’s function involves sound production and resonance, much like a trombone or other wind instrument. Air pushed through the elaborate internal tubes would have created a low-frequency, deep sound, perhaps a foghorn-like call. These low-frequency sounds travel well over long distances in forested environments, suggesting the crest was a tool for long-range communication within a herd. Studies using computed tomography (CT scans) have supported the idea that the crest acted as a resonating chamber.
The crest also served a clear function for visual display, being a prominent identifier for species and possibly for sex recognition during mating rituals. An older hypothesis suggested the crest might have played a role in thermoregulation. This theory proposed that blood vessels within the structure could help dissipate heat, but acoustic and visual display are now considered the primary functions.
Classification and Life in the Late Cretaceous
Parasaurolophus is classified as a member of the Hadrosauridae family, commonly known as the duck-billed dinosaurs. It belongs to the Lambeosaurinae subfamily, which is characterized by hollow cranial crests. This large herbivore could grow to lengths of up to 30 feet and weighed several tons, placing it among the larger animals of its ecosystem.
Its strong hind limbs and shorter forelimbs allowed it to move efficiently as both a biped and a quadruped. It likely walked on all fours while foraging and ran on two legs to escape predators. The dinosaur was a dedicated herbivore, using its wide, duck-like beak to crop vegetation. Its sophisticated dental battery, containing hundreds of continually replacing teeth, allowed for a grinding motion that processed tough plant material effectively.
Parasaurolophus lived during the Campanian stage of the Late Cretaceous period, a time when North America was divided by the Western Interior Seaway. Fossils are primarily found in the floodplains of what is now Alberta, Canada, and the southwestern United States, including New Mexico and Utah.