title: On the taxonomic status of the Thai endemic freshwater snake Parahelicops boonsongi, with the erection of a new genus (Squamata: Natricidae).
abstract: Parahelicops boonsongi Taylor & Elbel, 1958 is known from only three specimens from Thailand. It has been placed either in the genus Parahelicops Bourret, 1934, along with Parahelicops annamensis Bourret, 1934, or in the genus Opisthotropis Günther, 1872. We compared its morphological characters with those of P. annamensis and with three other relevant genera, Opisthotropis, Pararhabdophis Bourret, 1934, and Paratapinophis Angel, 1929. Parahelicops boonsongi is phenotypically distinct from Parahelicops annamensis, Opisthotropis, and all other natricine genera. We consequently erect a new genus, Isanophis gen. nov., to accommodate Parahelicops boonsongi.
authors.affiliation: Reptiles & Amphibiens, UMR 7205 OSEB, Département évolution et Systématique, CP 30, Muséum National d'Histoire Naturelle, 57 rue Cuvier, F-75231 Paris Cedex 05, France.; Email: pdavid@mnhn.fr.
authors.forename: Patrick
authors.initials: P
authors.lastname: David
authors.affiliation: Département des Vertébrés Récents, Institut Royal des Sciences Naturelles de Belgique, Rue Vautier 29, B-1000 Brussels, Belgium.; Email: osgpauwels@yahoo.fr.
authors.forename: Olivier S G
authors.initials: OS
authors.lastname: Pauwels
authors.affiliation: Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, Vietnam.; Email: nqt2@yahoo.com.
authors.forename: Truong Quang
authors.initials: TQ
authors.lastname: Nguyen
authors.affiliation: Society for Southeast Asian Herpetology, Im Sand 3, D-69115 Heidelberg, Germany.; Email: Gernot.Vogel@t-online.de.
authors.forename: Gernot
authors.initials: G
authors.lastname: Vogel
mesh_terms: D063147:Animal Distribution; D000825:Animal Structures / Q000033:anatomy & histology / Q000254:growth & development; D000818:Animals; D049628:Body Size; D017812:Colubridae / Q000033:anatomy & histology / Q000145:classification* / Q000254:growth & development; D005260:Female; D005618:Fresh Water / Q000032:analysis; D008297:Male; D009929:Organ Size; D013785:Thailand