On the classification and evolution of geckos
Article first published online: 7 MAY 2010
1954 The Zoological Society of London
Proceedings of the Zoological Society of London
Volume 124, Issue 3, pages 469–492, November 1954
How to Cite
Underwood, G. (1954), On the classification and evolution of geckos. Proceedings of the Zoological Society of London, 124: 469–492. doi: 10.1111/j.1469-7998.1954.tb07789.x
- Issue published online: 6 JUL 2010
- Article first published online: 7 MAY 2010
- Received 30th September 1953
- 1It is pointed out that the classification of geckos has remained unstable during the last eighty years.
- 2The eyelids and spectacles of geckos have been misunderstood; the eyelids are primitive, the spectacle is secondary.
- 3The majority of geckos have a pure rod retina in association with nocturnal habits, the rods derived by transmutation of cones.
- 4Two types of vertical pupil are distinguished, that with a straight edge and the Gekko-type with three lobes on anterior and posterior margins.
- 5Diplodactylus has a straight vertical pupil, Phyllodactylus a Gekko-type pupil, several species are reallocated.
- 6Narudasia is revived and distinguished from Quedenfeldtia on pupil shape.
- 7Gymnodactylus is redefined and restricted to South American forms with straight vertical pupil.
- 8Phyllurus is used for Australasian “Gymnodactylus” with straight vertical pupil.
- 9Cyrtodactylus is revived for Old World “Gymnodactylus” with Gekko-type pupil.
- 10Wallsaurus gen. nov. is proposed for Gymnodactylus horridus with straight padless digits and Gekko-type pupil.
- 11Arrangement of geckos as a superfamily Gekkonoidea with three families is proposed.
- 12Boulenger's Eublepharidae is revived for geckos with true eyelids with the addition of Holodactylus and Aeluroscalabates.
- 13Sphaerodactylidae fam. nov. is proposed for procoelous geckos with spectacle including Coleodactylus, Gonatodes, Lepidoblepharis, and Pseudogonatodes.
- 14The family Gekkonidae is restricted to amphicoelous geckos with spectacle and is divided into two subfamilies.
- 15Diplodactylinae subfam. nov. is proposed for Gekkonids with straight vertical pupil, twenty-two genera are placed here.
- 16Subfamily Gekkoninae is restricted to geckos with Gekko-type pupil, thirty-eight genera are placed here. Nine genera remain unplaced.
- 17Amphicoelous geckos appear also to have the two elements of the neural arch separate.
- 18The position of Uroplatus is discussed.
- 19The Eublepharidae are relicts of an archaic specialized group in old stable land areas.
- 20The Sphaerodactylidae are a strictly New World group centred on the Caribbean.
- 21The Diplodactylinae have a wide broken distribution and appear largely to have been supplanted by the Gekkoninae.
- 22Aristelliger is a relict of primitive archaic type in the Antilles. Bavaya and Rhacodactylus, also of peripheral distribution (New Caledonia), may be related to Aristelliger.
- 23The Gekkoninae have a wide range and it is suggested that there was an original dispersal of arboreal forms and that there has been independent reversal to terrestrial habits in several regions.
- 24The desert region of N. Africa and S.W. Asia contains a wealth of padless terrestrial geckos.
- 25Madagascar has eleven genera of geckos all with pads and none archaic.
- 26The Oriental Region has a wealth of Gekkoninae, no Diplodactylinae.
- 27South Africa and Australia both have notable groups of Diplodactylinae.
- 28The problem of the occurrence of a Tarentola in Cuba is discussed.
- 29The view that the procoelous condition is primitive and the amphicoelous condition secondary in geckos is upheld.
- 30It is argued that geckos whilst ancient are not primitive.
- 31A tentative outline of the evolutionary history of geckos is put forward.
- 32Evidences for parallel evolution in geckos are discussed in respect of the adaptation of the eye to dim lighting conditions and the secondary reversion to terrestrial habits with loss of digital pads.
- 33It is argued that the cases of parallel evolution are much better explained in terms of evolutionary opportunity as a relationship between organism and environment than in terms of any innate tendencies.
- 34In several stocks there is an increase over the “standard” number of 14 scleral ossicles, these parallel evolutions are not readily explicable.