Crotalinae2002

Marques et al. (2002) describe Bothrops alcatraz, a new species of the B. jararaca group, from Ilha dos Alcatrazes, a small island of the coast of Sao Paulo State, southeastern Brazil. The species is superficially very similar to B. jararaca, but differs in adult size (max SVL 55 cm vs. 120 cm in B. jararaca), body proportions, aspects of head scalation, and venom composition. The new species appears to feed primarily on lizards and centipedes, and the authors regard it as critically endangered due to its small range and the degradation of its habitat, partly due to the use of the island for target practice by the Brazilian Navy. See also the Projeto Alcatrazes homepage for info on the conservation status of the island.

Douglas et al. (2002) reviewed the systematics of the western rattlesnake (Crotalus viridis) complex, using a mtDNA phylogeographic approach, with special emphasis on the Colorado Plateau. Conventionally, the complex had been regarded as a single species, with 9 subspecies. Pook et al. (2000) carried out the first phylogeographic study of the complex, and suggested that three species might be recognisable, and Ashton & de Queiroz (2001) formally recognised an eastern species (C. viridis) and a western species, (C. oreganus) - see Crotalinae 2000 and Crotalinae 2001 pages on this site. Douglas et al. recognise seven species within the C. viridis complex:

Crotalus viridis - Prairie rattlesnake (including the conventional subspecies viridis and nuntius, the latter being considered a synonym of C. viridis)
Crotalus abyssus - Grand Canyon rattlesnake
Crotalus cerberus - Arizona black rattlesnake
Crotalus concolor - Midget faded rattlesnake
Crotalus helleri - Southern Pacific rattlesnake (including the conventional subspeces caliginis, whichis considered a synonym of helleri)
Crotalus lutosus - Great Basin rattlesnake
Crotalus oreganus - Northern Pacific rattlesnake

As in any complex group of snakes, it is likely that further research may yield further, different persectives on the species limits within the C. viridis complex.

Ashton, K.G. & A. de Queiroz (2001) Molecular Systematics of the western rattlesnake, Crotalus viridis (Viperidae), with comments on the utility of the D-Loop in phylogenetic studies of snakes. Molecular Phylogenetics and Evolution 21(2): 176-189.
Douglas, M. E., M.R. Douglas, G.W. Schuett, L.W. Porras & A.T. Holycross (2002) Phylogeography of the western rattlesnake (Crotalus viridis) complex, with emphasis on the Colorado Plateau. Pp. 11-50, in G. W. Schuett, M. Höggren, M. E. Douglas and H. W. Greene, (eds.), Biology of the Vipers. Eagle Mountain Publishing, Eagle Mountain, UT.
Pook, C.E., W. Wüster & R.S. Thorpe (2000) Historical biogeography of the western rattlesnake (Serpentes: Viperidae: Crotalus viridis), inferred from mitochondrial DNA sequence information. Molecular Phylogenetics and Evolution, 15: 269-282. pdf

David et al. (2002) describe Trimeresurus gumprechti from hilly areas of northeastern Thailand. The new species is related to T. stejnegeri, with which it was formerly confused. The new species is large (to 130 cm), and has so far been found in the Thai Provinces of Loei, Phitsanulok, Phetchabun and Chaiyaphum, and may also occur in neighbouring provices, as well as northwestern Laos. Further work on the status of this form and the recently described T. vogeli (see Crotalinae 2001 page) is in progress in several laboratories.