Open AccessThe retina of Psammodynastes pulverulentus (Boie, 1827) and Telescopus fallax (Fleischmann, 1831) with a discussion of their phylogenetic significance (Colubroidea, Serpentes)
Author(s) -
Rasmussen J. B.
Publication year - 1990
Publication title -
journal of zoological systematics and evolutionary research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.769
H-Index - 50
eISSN - 1439-0469
pISSN - 0947-5745
DOI - 10.1111/j.1439-0469.1990.tb00381.x
Subject(s) - retina , biology , phylogenetic tree , zoology , taxonomy (biology) , anatomy , genetics , neuroscience , gene
The retinas of the rear‐faned snakes Psammodynastes pulverulentus and Telescopus fallax have been examined. P. pulverulentus has a simplex retina in which the proportion between the numbers of outer and inner nuclear layers is 1:8 which means that P. pulverulentus has a typical diurnal retina. This is further stressed by the find of a shallow, temporal fovea until now only known from a single snake genus, Ahaetulla. T. fallax has a two‐tier retina with double cones, with almost the same numbers of outer and inner nuclear layers (1:1.3) which means that T. fallax has a typical nocturnal retina. ‐ The two species are usually regarded as belonging to the boigine (s. str.) snakes, but the presence of double cones in both species and not least the presence of a retinal fovea in Psammodynastes , makes this assignment dubious, and their probable relationships to other Colubroids are discussed.