{{Speciesbox | image = Urutú-cruzeiro (Bothrops alternatus).jpg | genus = Bothrops | species = alternatus | authority = A.M.C. Duméril, Bibron & A.H.A. Duméril, 1854 | synonyms = *Craspedocephalus Brasiliensis (<small>non Lacépède) Gray, 1849 Bothrops alternatus A.M.C. Duméril, Bibron & A.H.A. Duméril, 1854Trigonocephalus alternatus – Jan, 1859 Lachesis alternatus – Boulenger, 1896 Lachesis alternata – Boettger, 1898 Lachesis inaequalis Magalhaes, 1925 Bothrops alternata – Amaral, 1925 Lachesis (Bothrops) alternata – Gliesch, 1931 Trimeresurus alternatus – Pope, 1944 Bothrops alternatus – J.A. Peters & Orejas-Miranda, 1970 Rhinocerophis alternatus – Fenwick et al., 2009 }}Common names: yarará grande, urutu, wutu, crossed pit viper.Bothrops alternatus' is a highly venomous pit viper species found in South America (Brazil, Paraguay, Uruguay and Argentina). Within its range, it is an important cause of snakebite. The specific name, alternatus, which is Latin for "alternating", is apparently a reference to the staggered markings along the body. No subspecies are currently recognized. Description Size Large and stout, this terrestrial species reportedly exceeds in total length, although the verified maximum is . Most specimens are in total length, with females being significantly longer and heavier than males. Color and markings The scalation includes 25-35 (usually 27-31/29-33 in males/females) rows of dorsal scales at midbody, 155-183/164-190 ventral scales in males/females, and 38-53/30-44 subcaudal scales in males/females. On the head there are 8-13 strongly keeled intersupraocular scales, 8-10 supralabial scales, none of which are fused with the prelacunal, and 12-14 sublabial scales. The color pattern is exceedingly variable. The ground color may be brown, tan or gray, sometimes with an olive cast. The top of the head is usually chocolate brown to almost black with a range of transverse and longitudinal tan to white markings. On the body, there is a series of 22-28 dorsolateral markings that are chocolate brown to black in color and boldly bordered in cream or white. Along the vertebral line, these markings may either oppose or alternate. Each marking is widened and invaded from underneath by the paler ground color so that it either looks like a cross, encloses a darker blotch, or divides the marking into three parts to give it the shape of a headphone. On the tail, the pattern fuses to form a zigzag pattern. In some specimens, the pattern is so concentrated that there is no difference in color between the markings and the interspaces. The ventral surface includes a dark brown to