Forelimb posture in chilesaurus diegosuarezi (dinosauria, theropoda) and its behavioral and phylogenetic implications

Nicolás R. Chimento, Federico L. Agnolin, Fernando E. Novas, Martín D. Ezcurra, Leonardo Salgado, Marcelo P. Isasi, Manuel Suarez, Rita De La Cruz, David Rubilar-Rogers, Alexander O. Vargas

Research output: Contribution to journalReview articlepeer-review

5 Citations (Scopus)


Many dinosaur skeletons show evidence of behavior, including feeding, predation, nesting, and parental care. The resting posture of the forelimbs has been studied in some theropod species, in relation to the acquisition of flight in advanced maniraptoran theropods. Chilesaurus diegosuarezi is a bizarre tetanuran recently described from the Toqui Formation (latest Tithonian) of southern Chile that is represented by multiple well-preserved and articulated specimens. The aim of the present work is to analyze the forelimb posture of four articulated specimens of Chilesaurus diegosuarezi, focusing on its anatomical description, and phylogenetic and behavioral implications. All the preserved specimens show strongly ventrally flexed arms with the hands oriented backwards, an arrangement that closely resembles those in dinosaur specimens previously described as preserving resting posture, such as Mei long, Sinornithoides youngi and Albinykus baatar. As a result, it seems that individuals of Chilesaurus diegosuarezi have been in passive activity (e.g. feeding, resting) when they were buried quickly, allowing their fossilization in life position and preserving the forelimb resting posture. The arrangement of the forelimb bones in Chilesaurus could show the first evidences of the structures linked to the muscles that flex the forearms, features related with the acquisition of flying control in advanced maniraptorans.

Original languageEnglish
Pages (from-to)567-575
Number of pages9
Issue number5
Publication statusPublished - 1 Jan 2017


  • Flexion
  • Flight evolution
  • Forelimb resting posture
  • Soft tissue

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Palaeontology


Dive into the research topics of 'Forelimb posture in chilesaurus diegosuarezi (dinosauria, theropoda) and its behavioral and phylogenetic implications'. Together they form a unique fingerprint.

Cite this