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| False Water Cobra, Hydrodynastes gigas (Dumeril, Bibron, and and Dumeril, 1854). Photographs of a captive animal. This snake has also been placed in the genus Cyclagras. It uses streams and ponds in open scrub and woodlands. It occurs in Bolivia, Paraguay, southern Brazil and northern Argentina. The false water cobra is diurnal and forages for vertebrates on the ground. Capturing prey uses both envenomation and constriction. Its venom is potentially dangerous to humans. Females lay clutches up to 36 eggs. Adult size may exceed 2 m. |
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| Water Mapepire, Helicops angulatus (Linnaeus, 1758). Photographed in Trinidad's Northern Basin. This is a highly aquatic snake that uses shallow water in disturbed habitats as well open wetlands with submergent vegetation. It feeds upon aquatic vertebrates. Adults are usually 0.6-0.8 m. Female lay eggs in at least some populations, but the eggs may be in an advanced state of development and hatch within a few days of being laid. H. angulatus has an Amazonian distribution. |
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| Linne's Royal Snake, Liophis reginae (Linnaeus, 1758) is widely distributed in South America, but this specimen is L. r. zweifeli, a race found in the Caribbean Coastal Range of Venezuela and Trinidad. It is a forest and forest edge snake photographed in the Arima Valley, Trinidad. It feeds on frogs and lizards and it is usually not far from water. |
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| Shaw's Black Backed Snake, Liophis melanotus (Shaw, 1802). Photographed at Charlottesville, Tobago. Adults reach at least 700 mm. It inhabits secondary growth and agricultural areas and feeds on frogs and lizards. While it is terrestrial, it often forages along streams. This specimen is referable to the subspecies L. m. neosus. |
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| Calico False Coral Snake, Oxyrhopus petola (Linnaeus, 1758). Potograph was taken in northeastern Costa Rica. Adults reach about 1.1 m, most specimens are 700-800 mm. Most specimens are banded, occasionally large adults are almost uniform black (middle photo). It inhabits lowland forest and savanna and feeds on lizards, snakes and small mammals. O. petola ranges from Veracruz, Mexico southward to Bolivia and Argentina. This snake has also been called O. petolarius, Pseudoboa petolaand Clelia petola. |
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| Neuwied's False Boa, Pseudoboa neuwiedii (Dumeril, Bibron and Dumeril, 1854). Photographed in Trinidad. This is a widespread species ranging from Panama and Columbia east to Suriname and south to Brazil. It is also present on Trinidad and Tobago. Adults may exceed a meter in length, but are often smaller. It is crepuscular and nocturnal in forest and savanna, but it also uses distributed environments and agroecosystems (plantations). Clutches of 3-9 eggs are laid in leaf cutter ant nests. The venom of these snakes is potentially dangerous to humans. |
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| Tropical Flat Snake, Siphlophis compressus (Daudin, 1803). Photographed in Trinidad. Adults may exceed a meter in total length, most specimens are slightly less than a meter. It is a forest and forest edge snake that is nocturnal and crepuscular. Food is mostly lizards and possibly arthropods. A clutch of 12 eggs was found in a leaf cutter ant nest, but this may have been two clutches from different females. Despite the fact that many authors consider this an arboreal snake, six of seven specimens I found were on the ground, and only one was in a bush. Juveniles tend to be more brightly colored than the adults. This snake was long placed in the monotypic genus Tripanurgos. |
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| Xenodontid snakes are a South American and West Indian clade. Vidal et al. (2000, Molecular Phylogenetics and Evolution 14:389-402) used DNA sequence analyses of portions
of two mitochondrial genes (12S and 16S ribosomal
RNA) from 85 species.
They suggested an
Asian–North American origin of for this group. West
Indian xenodontines (including endemic genera and
members of the genus Alsophis) appear to form a
monophyletic group belonging to the South American
clade. They also found support for a mid-Cenozoic origin by dispersal using
ocean currents. Within South American
mainland xenodontines, the tribes Hydropsini, Pseudoboini,
and Xenodontini are monophyletic. Their results also suggest that some morphological and ecological
traits concerning maxillary dentition, macro habitat
use, and foraging strategy have appeared multiple
times during the evolution of xenodontine snakes. Thus, while many of these snakes have enlarged, grooved rear fangs some do not. |
