INVESTIGADORES
ABDALA Virginia Sara Luz
congresos y reuniones científicas
Título:
Does Skull Shape Support the Pygopodids Being Nested within the Geckos?
Autor/es:
JUAN D. DAZA, ALEXANDRA HERRERA, RICHARD THOMAS, VIRGINIA ABDALA
Lugar:
Saint Louis Missouri
Reunión:
Congreso; Joint Meeting of Ichthyologist and Herpetologists; 2008
Resumen:
Whether pygopodids are members of the Gekkota has been a debated issue for along time. Nuclear DNA sequences and one myological character place them as thesister group of the diplodactylinid geckos, while evidence from retinal structuressuggests that they diverged early from all geckos. We constructed a gekkotanmorphospace using 17 landmarks located on 250 gekkotan skulls in dorsal view. Weused a sample of 108 species from the 5 extant clades. Our geometric morphometricanalysis revealed that pygopodids occupy a position adjacent to the geckos and thattheir skull morphology is very distinct from their putative sister taxa. The relativewarps analysis was used to test the phylogenetic hypothesis of the major groups ofgekkotans, and it revealed that some closely related taxa exhibit some overlap, whichsuggests a possible common ancestry. This is evidenced in the leaf litter geckos,Sphaerodactylinae, which partly overlapped their sister taxa, Gekkoninae. Thehypothesis of a pygopodid-eublepharine clade was not supported, since thesegroups were represented as distinct clusters. We offer two alternate explanations: 1)morphological differentiation occurred rapidly between these groups, leaving nointermediate forms, or 2) these groups are not closely related, which is congruentwith the absence of type C-double visual cells in pygopodids that occur in all geckos.Results based on the 17 homologous landmarks examined in this study supportedthe second explanation. Furthermore, some sphaerodactylines appeared closer topygopodids in the relative warps ordination space, which partly suggests that theyshare a similar skull shape and that their similarity could be attributed to convergentminiaturization process.