Concavenator, a fascinating theropod dinosaur, offers insights into prehistoric life. Its discovery marked a significant paleontological event, revealing unusual features for its kind. Understanding its discovery context provides a clearer picture of its existence and the ancient world it inhabited.
The Primary Discovery Site
Concavenator was unearthed in Spain, in the province of Cuenca. The Las Hoyas fossil site, nestled in the Serranía de Cuenca basin, is the site of this significant find. This area is a protected site due to its paleontological richness.
The Las Hoyas site is part of the La Huérguina Formation, a geological unit recognized as a “Konservat-Lagerstätte.” This term signifies a deposit with exceptional fossil preservation. The Museo de Paleontología de Castilla-La Mancha in Cuenca now houses the Concavenator holotype specimen, designated MCCM-LH 6666.
Geological Time and Environment
Concavenator lived during the Early Cretaceous period, specifically the Barremian age, approximately 125 to 130 million years ago. This geological epoch saw a warmer global climate, with forests extending into higher latitudes.
The paleoenvironment of the Las Hoyas site during the Barremian was a shallow freshwater lake or lagoon system. This wetland was situated in a subtropical climate, characterized by alternating wet and dry seasons. The finely laminated limestones of the La Huérguina Formation were deposited in these lacustrine (lake) and palustrine (marsh) environments.
This setting contributed to the exceptional preservation of fossils, including the Concavenator. The presence of microbial mats and rapid burial by sediment helped to prevent decay, leading to remarkably detailed fossilization.
Significance of the Discovery Site
The Las Hoyas site’s unique geological conditions were instrumental in preserving Concavenator with extraordinary detail, making it a significant discovery. The nearly complete and articulated skeleton allowed paleontologists to observe distinctive anatomical features that might otherwise have been lost.
Among these features are two unusually tall vertebrae located just in front of the hips, which formed a prominent crest or hump on the dinosaur’s back. While the exact function of this structure remains a subject of scientific discussion—possibly for display, temperature regulation, or fat storage—its preservation at Las Hoyas provided direct evidence of this unique adaptation.
Furthermore, the fossil revealed structures on Concavenator’s ulna (forearm bone) that resemble “quill knobs,” bony bumps found in modern birds where feathers attach. If these indeed indicate quill-like structures, it would suggest the presence of such integumentary features in a large theropod much earlier than previously confirmed. While some debate exists regarding their interpretation as muscle scars, the exceptional preservation at Las Hoyas allowed for this intriguing observation and ongoing research.
The detailed preservation at Las Hoyas also provided impressions of Concavenator’s scales on its tail and feet, resembling those of a bird. The characteristics of the site were thus crucial for revealing these specific details, significantly advancing the understanding of dinosaur evolution and the diverse ecosystems of the Early Cretaceous.