Salamander DNA reveals evidence of older land connection between Central and South America
by Smithsonian staff
The two continents are generally believed to have been joined together around three million years ago by the formation of a land bridge–what is now Panama–that sealed up the sea channel between them.
However, a new study of salamanders in South America by a research team lead by Kathryn Elmer of the University of Glasgow, has found evidence that challenges these assumptions and supports a controversial claim by Carlos Jaramillo, a paleontologist at the Smithsonian Tropical Research Institute in Panama, that most of the Isthmus of Panama was formed around 23 million years ago.
The fusion of both land masses led to a two-way migration of animals called the ‘Great American Biotic Interchange’, where animals that had previously evolved separately moved between the two continents, increasing the biodiversity in both regions.
The relative dearth of species of salamander in South America–around 30–compared to Central America, where there are more than 300 species, is usually attributed to the relatively short time the tiny amphibians have had to make their way south down the Isthmus of Panama–a thin strip of land only 30 miles wide at its narrowest point.
However, using DNA analysis, Elmer found that salamanders in South America had much greater genetic divergence from their Central American cousins than should be expected if salamanders migrated across a three- million-year-old land bridge…
The two new salamanders belong to the genus Bolitoglossa, otherwise known as tropical climbing or web-footed salamanders. One of the salamanders (B. leandrae) has been named after an 11-year old girl who became friends with the team whilst they conducted their fieldwork. “Leandra grew fascinated by the world of amphibians,” explains team leader Aldemar Acevedo. “She was eager to learn about our work and became an excellent spokesperson for nature conservation among the community.”
Bolitoglossa leandrae is a relatively small salamander (its body measures roughly 2.5 cm in length, about the size of a 50 pence, 20 cent or US quarter coin) with a narrow head and long, slender tail. Males are dark brown with thin yellow stripes along the length of the body and females are reddish brown.
Bolitoglossa tamaense is slightly longer than B. leandrae (the body of the longest specimen measured approximately 5 cm, or the same as the height of a credit card) and has a broad head and relatively long body and legs. A number of different colourations and patterns were recorded, but the body is generally brown or dark red, and the tail and limbs can be dark brown, red, orange or yellow…
Blue Vipers, Endangered Frogs, and Threatened Birds Protected by New Guatemalan Reserve
media release by ABC, Robert Johns
Conservationists are celebrating the establishment of the new 6,000-acre Sierra Caral Amphibian Reserve in Guatemala, which will protect some of the country’s most endangered wildlife. The reserve is home to a dozen globally threatened frogs and salamanders, five found nowhere else in the world, three species of threatened birds, and the recently discovered Merendon Palm-pitviper (Bothriechis thalassinus), an arboreal, blue-toned viper.
Tucked away in the eastern corner of Guatemala near the Caribbean Sea, and running along the Honduran border, the Sierra Caral is an isolated mountain range that is home to numerous rare and endangered animals and plants. Exploration of these mountains has yielded several new discoveries of beetles, salamanders, frogs, and snakes over the past two decades.
The site will offer protections for many birds including threatened species such as: the
Highland Guan, Great Curassow and Keel-billed Motmot. Furthermore, the site is known as a haven for an abundance of migratory birds including the Canada Warbler, Kentucky Warbler, Wood Thrush, Painted Bunting, Worm-eating Warbler, and Louisiana Waterthrush…
(photos: TL - Great Curassow by Greg Homel; TR - Merendon Palm-pitviper by Robin Moore; Mid - Aerial view by Robin Moore; BL - Giant Palm-footed Salamander by Robin Moore; BR - Carlos Vasquez Almazan next to old growth tree by Don Church)
The worm salamander, Oedipina taylori, is a species of salamander in the family Plethodontidae (the lungless salamanders). It is found in El Salvador, Guatemala, and Honduras. Its natural habitats are subtropical or tropical moist lowland forests and subtropical or tropical moist montanes. It is threatened by habitat loss. (via: Wikipedia)
Newly Listed as ‘Critically Endangered’: Chuj Climbing Salamander
(photo: Todd Pierson)
The Chuj Climbing Salamander (Dendrotriton chujorum), a species of dwarf salamander from Guatemala, is another addition to the critically endangered category of the 2011 IUCN Red List. The salamanders are found in a limited area of hardwood forest, much of which has been cut for farming and firewood. But local authorities are also working hard to protect a remaining stretch of forest where the amphibians still thrive.
“It’s a classic example of how humans impact biodiversity around the world,” Miller said. “We have the power to destroy—but also the power to protect.”
20 Years of Discovery with Conservation International: The “ET salamander”, Bolitoglossa sp. nov, discovered in Ecuador in 2009.This genus of salamanders has fully webbed feet which help them climb high into the canopy of tropical forests; they also have no lungs and breathe instead through their skin. This new species was found in the wet forests of the tepuis in southern Ecuador. (Photo: Jessica Deichmann)