Abstract

New observations from the only studied Upper Jurassic dinosaur unit in South America, the Banos del Flaco Formation, Chile, are presented herein. The original description of the ichnospecies Iguanodonichnus frenki contains several mistakes and information that needs updating. Therefore, we provide a redescription, including new data collected in the field, that supports I. frenki as a sauropod in origin on the basis of the following features: step angles average less than 110 degrees; pes prints intersect the trackway midline; pes prints are longer than wide, with the long axis rotated outward; the claw impression of digit I is prominent and directed forward: and claws on digits 11, 111, and IV are strongly reduced. These morphological characteristics might give clues about the pes morphology of the South American Jurassic sauropods, whose foot bone remains are scarce. The presence of this sauropod ichnospecies in the Late Jurassic agrees with Early-Middle Jurassic faunal associations in South America. (c) 2005 Elsevier Ltd. All rights reserved.