Nectridea is an extinct order of lepospondylamphibians from the Carboniferous and Permian periods, including animals such as Diplocaulus. In appearance, they would have resembled modern newts or aquatic salamanders. They had long flattened tails to aid in swimming, and well-developed hind limbs, with a full set of five toes each. The forelimbs were somewhat reduced however, and like modern amphibians typically had only four toes each.
^Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 54. ISBN1-84028-152-9.
Ahlberg, P. E. & Milner, A. R. 1994: The origin and early diversification of tetrapods. Nature: vol. 368, 7 April, pp. 507-514
Anderson, J. S. 1998: Phylogenetic analysis of the Lepospondyli (Tetrapoda). Journal of Vertebrate Paleontology. Vol. 18, #3, Suppl. to #3, pp. 24A
Carroll, R. L., 1988: Vertebrate paleontology and evolution. W. H. Freeman and company, New York, 1988, 698.
Carroll, R. L., 1988: Appendix. 594-648. in Carroll, R. L., 1988: Vertebrate paleontology and evolution. W. H. Freeman and company, New York, 1988, 698.
Carroll, R. L. 1996: Revealing the patterns of macroevolution. Nature: vol. 381, 2 May, pp. 19-20
Clack, J. A., 1998: A new Early Carboniferous tetrapod with a mélange of crown-group characters. Nature: vol. 394, 2 July, pp. 66-69
Shubin, N., 1998 [preview]: Evolutionary cut and paste. Nature: vol. 394, 2 July, pp. 12-13
Vallin, G. & Laurin, M., 2004: Cranial morphology and affinities of Microbrachis, and a reappraisal of the phylogeny and lifestyle of the first amphibians. Journal of Vertebrate Paleontology: Vol. 24, #1, pp. 56-72