Pistas de dinosaurios teropodos del Cretacico Inferior de la Formacion Chacarilla, Norte de Chile.Theropod Dinosaur Trackways from the Lower Cretaceous of the Chacarilla Formation, Chile.
Theropod Dinosaur Trackways from the Lower Cretaceous of the Chacarilla Formation, Chile
Author
Rubilar-Rogers, David
Moreno, Karen
Blanco, Nicolas
Calvo, Jorge O.
Full text
http://www.andeangeology.cl/index.php/revista1/article/view/V35n1-a0910.5027/andgeoV35n1-a09
Abstract
Se describen dieciseis pistas de dinosaurios teropodos localizadas en el sitio III (Cretacico Inferior?) de la Formacion ChacariUa (Jurasico-Cretacico Inferior) en Quebrada ChacariUa, norte de Chile. La unidad con huellas fue depositada en un ambiente de rio meandriforme y presenta recurrentes niveles con asociaciones de trazas. Las icnitas tienen una direccion paralela a la direccion del flujo de agua. Dos morfotipos de huellas de teropodos fueron reconocidos: A) Con los digitos II y IV, ocupando cerca de 0,5 veces el largo total de la huella y B) con los digitos II y IV ocupando menos de 0,35 veces la longitud total de la huella. Estimaciones de similar velocidad (~7 km/h) de dos pistas paralelas pertenecientes al morfotipo A, sugieren caminata sincronizada. Ademas, describimos algunas de las huellas de teropodos mas grandes de America del Sur (>60 cm), las que corresponden al morfotipo B.ABSTRACT:We describe sixteen theropod dinosaur trackways from site III (Lower Cretaceous?) of the Quebrada Cha-carilla in the ChacariUa Formation (Jurassic-Lower Cretaceous), northern Chile. The trackbed belongs to a meandering river environment, with recurrent track assemblages. We find that the main direction of the ichnites from site III parallels that of water flow. Two theropod footprint morphotypes are recognized: A) digit II and IV occupying about 0.5 times the total footprint length, and B) digit II and IV occupying less than 0.35 times the total footprint length. We estimate similar speed (~7 km/h) for the two parallel theropod trackways of morphotype A, suggesting synchronized walking. We also describe some of the largest theropod footprints from South America (>60 cm), which are all of morphotype B. We describe sixteen theropod dinosaur trackways from site III (Lower Cretaceous?) of the Quebrada Cha-carilla in the ChacariUa Formation (Jurassic-Lower Cretaceous), northern Chile. The trackbed belongs to a meandering river environment, with recurrent track assemblages. We find that the main direction of the ichnites from site III parallels that of water flow. Two theropod footprint morphotypes are recognized: A) digit II and IV occupying about 0.5 times the total footprint length, and B) digit II and IV occupying less than 0.35 times the total footprint length. We estimate similar speed (~7 km/h) for the two parallel theropod trackways of morphotype A, suggesting synchronized walking. We also describe some of the largest theropod footprints from South America (>60 cm), which are all of morphotype B.