Abstract
The morphology of the tectum mesencephali and the medial pallium is studied in species representing the six families of caecilians (Amphibia: Gymnophiona) in order to determine whether differences in brain morphology are related to function, phylogenetic history, or life history strategies. In general, the caecilian tectum is characterized by simplification in having little to no lamination and few migrated cells. The degree of morphological complexity differs between species and between brain regions. Our data suggest that changes in brain morphology are due to a mosaic of different influences. We did not find a strict correlation between visual system reduction and tectal morphologies. However, phylogenetic effects exist. The greatest degree of morphological complexity is found in members of the Rhinatrematidae, a family that is considered basal to the lineage. Thus, simplification of brain morphology in caecilians must be considered a secondary or derived rather than a primitive feature. Direct development and miniaturization are correlated with the greatest simplification in the tectum mesencephali and medial pallium. There is a relationship between differences in brain morphology and heterochrony in caecilians, as in other...Continue Reading
References
Jan 1, 1976·International Review of Cytology·H Szarski
Apr 1, 1992·Journal of Morphology·M H Wake
Dec 8, 1988·The Journal of Comparative Neurology·G RothD B Wake
Dec 8, 1988·The Journal of Comparative Neurology·D B WakeG Roth
Jan 1, 1987·Brain, Behavior and Evolution·B L FinlayD R Sengelaub
Jan 1, 1986·Histochemistry·M K HallyR C Bruce
Jun 1, 1969·The Journal of Comparative Neurology·H D Potter
Jul 1, 1984·Cancer Genetics and Cytogenetics·R BernsteinB Mendelow
Nov 21, 1983·Journal of Theoretical Biology·H Szarski
Jan 1, 1982·Annual Review of Biophysics and Bioengineering·T Cavalier-Smith
May 24, 1994·Proceedings of the National Academy of Sciences of the United States of America·G RothD B Wake
Jan 1, 1993·Brain, Behavior and Evolution·G RothD B Wake
Nov 1, 1987·Evolution; International Journal of Organic Evolution·Stanley K Sessions, Allan Larson
Sep 1, 1990·Journal of Morphology·Andrea Schmidt, Marvalee H Wake
Jul 1, 1986·Journal of Morphology·Marvalee H Wake
Citations
Jun 1, 1998·Journal of Morphology·Andrea Schmidt, Marvalee H Wake
May 7, 2002·Evolution; International Journal of Organic Evolution·Jennifer Yeh
May 4, 2011·Journal of Morphology·Hillary C Maddin