Tiny Lizard Fits on the Face of a U.S. Quarter
- The world's smallest reptile, a 16-millimeter lizard, has been discovered in the Caribbean islands by Pennsylvania State University Evolutionary Biologist Blair Hedges and University of Puerto Rico Biologist Richard Thomas. The discovery is published in this month's Caribbean Journal of Science
. The Jaragua Sphaero, or dwarf gecko, is believed to exist only on Beata Island and nearby areas in the Dominican Republic's Jaragua National Park.
The discovery of the lizard is just one of several miniature species found in the Caribbean. The world's smallest bird, the Bee Hummingbird, is found only in Cuba. The tiny hummingbird measures barely five centimeters long, hardly twice the size of a penny. The Northern Hemisphere's smallest frog, a one-centimeter long frog known as Monte Iberia Eleuth, ties as the world's smallest frog. The world's smallest snake, the Lesser Antillean Threadsnake, is so thin it could slither though a pencil if the lead were removed. The snake is found in the West Indies.
Species of extreme size, both smallest and largest, often evolve on islands, where they face fewer competitor species than they would on the continents.
The Jaragua Sphaero, which measures less than three quarters of an inch from snout to the base of the tail, is similar in size to a lizard endemic to the British Virgin Islands, and also ties for the world's smallest amniote, a group consisting of all mammals, reptiles and birds.
Although much is still unknown about the diversity of life in the Caribbean, Michael Smith, Senior Research Fellow for the Center for Applied Biodiversity Science at Conservation International, says we have enough information to appreciate its critical importance. "The Caribbean is one of the richest places on Earth in terms of unique species," he says, "but they are extremely threatened. If the Caribbean continues to lose species at the current rate, then one of the world's most distinctive natural systems will be devastated in our lifetimes."
According to Conservation International President Russell Mittermeier, "The Caribbean has one of the highest concentrations of endemic species on Earth." Many biologists believe it ranks as one of the world's top biodiversity hotspots, defined as the 25 places in the world that represent a combined 1.4 percent of the Earth's landmass, but which contain a staggering 60 percent of all terrestrial species diversity.
Rapid population growth is a major threat to the Caribbean's species. "If you add all of the islands together, you would have a landmass about the size of Oregon," says Smith. "But if you add their populations, you would have as many people as the states of Oregon, Washington and California combined. Imagine the effects of concentrating so many people in these small islands, and it becomes clear why so many species are threatened."
Agricultural practices and barriers to regional cooperation between the Caribbean islands also play a role in the loss of biodiversity in the region, as does lack of access to centralized biological data within the Caribbean.
"Our discovery illustrates that we still don't know everything about the Earth's species, even in areas that are very close to the United States," says Blair Hedges, who discovered the lizard. "We did not even know the species existed, although the area has been studied by biologists for several hundred years."
The Jaragua Sphaero (scientific name: Sphaerodactylus ariasae) is named in honor of Yvonne Arias, who heads the Dominican conservation organization Grupo Jaragua. Arias, a herpetologist, is respected as a leading voice for preserving Caribbean biodiversity. Grupo Jaragua was formed to advocate protection of Jaragua National Park, on the island of Hispanola. She was instrumental in getting the people who already lived on that land to preserve it; today, residents of the park are playing a major role in running it on their own. Grupo Jaragua is an example of the several new conservation organizations working to protect the region's biodiversity.
The Center for Applied Biodiversity Science (CABS), based at Conservation International, strengthens the ability of CI and other institutions to accurately identify and quickly respond to emerging threats to Earth’s biological diversity. CABS brings together leading experts in science and technology to collect and interpret data about biodiversity, to develop strategic plans for conservation and to forge key partnerships in all sectors toward conservation goals.