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ABSTRACT—The fossil snakeNajash rionegrina, from the Cenomanian–Turonian (Upper Cretaceous) of Argentina, is reinterpreted after examination of the type and referred material. The current diagnosis is emended in the light of important considerations that cast doubt on the attribution of type and referred specimens (a braincase, a quadrate, and two dentary/lower jaw fragments) used to systematize this taxon. Alternative interpretations of the anatomy of the sacrum and hind limbs are proposed. Following the reevaluation of the anatomy of the type specimen and the removal from this taxon of the above-mentioned referred material, the phylogenetic position ofN. rionegrinawas tested in a series of maximum parsimony analyses that included all groups of extant snakes, all best-known fossil snakes (i.e.,Pachyrhachis,Haasiophis,Eupodophis, Madtsoiidae, andDinilysia), and alternative outgroups. Regardless of the outgroup used to polarize the character-state transformations, our phylogenetic analyses found no support for the hypothesis thatNajash rionegrinaoccupies a position as the most basal snake. Depending on the outgroup,Najashis placed (1) in a position basal to all living snakes, but more derived than other fossil forms (most notablyPachyrhachis,Eupodophis, andHaasiophis); or (2) as the most basal representative of a clade of fossil snakes that is the sister group of living snakes; or (3) as the most basal representative of a clade of fossil snakes that is located between the Scolecophidia and the Alethinophidia. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free atwww.tandfonline.com/UJVP [ABSTRACT FROM AUTHOR]

The article focuses on a research work conducted to determine the correct spelling of the generic name of Rhachidelus brazili Boulenger that is a pseudoboine snake endemic to northern South America and to report on the confirmed specimens of this species from Paraguay. It mentions that it is a large healthy snake and has as many as 25 scale rows in mid body. It also mentions that in Argentina rhachidelus brazili is popular from only two specimens that are provincia Misiones, Santa Ana and provincia córdoba, tulumba. It reports that its presence close to Paraguayan border in Brazil and Argentina determined the probability of its occurrence in Paraguay. It also reports on the specimen of this snake deposited in the Para La Tierra collection Laguna Blanca in San Pedro, California.