Loading ...
Sorry, an error occurred while loading the content.

all Pterosauria had akinetic skulls

Expand Messages
  • Stephan Pickering
    Edna Prondvai & Attila Osi, 2011. Potential for intracranial movements in pterosaurs. The Anatomical Record IN PRESS + Supporting Information. ABSTRACT. Based
    Message 1 of 1 , Apr 1, 2011
      Edna Prondvai & Attila Osi, 2011. Potential for intracranial movements in pterosaurs. The Anatomical Record IN PRESS + Supporting Information. ABSTRACT. Based on comparative anatomical, morphological, and phylogenetic considerations the potential of pterosaurs for cranial kinesis is assessed. Our investigation shows that whereas skeletally mature derived pterodactyloids have completely fused, rigid and doubtlessly akinetic skulls, skeletally immature derived pterodactyloids and more basal pterosaurs possess key features in the morphology of their otic and basal joints that are suggestive of cranial kinesis, namely streptostyly. In addition, pterosaurs exhibit an evolutionarily informative trend in the degree of cranial ossification, where it is low in most nonpterodactyloids (here named bifenestratans), intermediate in Rhamphorhynchus and Archaeopterodactyloidea, and high in derived pterodactyloids. Incomplete fusion could also indicate loose connections between skull elements. However, another crucial anatomical requirement of a kinetic skull, the permissive kinematic linkage, is absent in all pterosaurian taxa. The fact, that the presence of permissive kinematic linkages in the skull is also a prerequisite of all types of cranial kinesis, provides hard evidence that all members of Pterosauria had akinetic skulls. Thus, the presence of the morphological attributes indicative of intracranial movements in some pterosaurs must be explained on grounds other than real potential for cranial kinesis. It could either be of mechanical or ontogenetic importance, or both. Alternatively, it might be considered as the morphological remnant of a real, kinetic skull possessed by the diapsid ancestors of pterosaurs.    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      STEPHAN PICKERING / Chofetz Chayim ben-Avraham
      Jewish dinosaurologist / Heretic spiritist
      2333 Portola Drive # 4
      Santa Cruz, California 95062-4250
      IN PROGRESS: Mutanda Dinosaurologica: in memory of Samuel Paul Welles (9 November 1909--6 August 1997)
      IN PROGRESS: Dialects of a synaesthetic heart: poetics for Faline Pickering (23 January 1949--24 August 2008)
      IN PROGRESS: Alfred Russel Wallace's KING KONG: the semioptics of Willis O'Brien
      MEMBER 13853: Society of Vertebrate Paleontology
      One concept corrupts and confuses the others. I am not speaking of the Evil whose limited sphere is ethics; I am speaking of the infinite. ...Reality is not always probable, or likely. -- JORGE LUIS BORGES
      You never know what's comin' for you. -- QUEENIE in ERIC ROTH'S  The curious case of Benjamin Button
      What if G-d didn't say it? -- BART EHRMAN
      Seek the sacred with the ordinary. Seek the remarkable with the commonplace. -- REB NACHMAN OF BRATSLAV
      G-d is all that exists, but not all that exists is G-d. -- R. MOSHE CORDOVERO

    Your message has been successfully submitted and would be delivered to recipients shortly.