One of the world's tiniest lizards has been discovered by keen-eyed
researchers in Madagascar. The miniature chameleon, Brookesia micra,
reaches a maximum length of just 29mm. German scientists also found a
further three new species in the north of the island. The lizards were
limited to very small ranges and scientists are concerned they could be
at risk from habitat disturbance. The discovery is reported in the
journal PLoS ONE.
The research team, led by Dr Frank Glaw from the Zoologische
Staatssammlung in Munich, have a specialist knowledge of Madagascar's
dwarf chameleons having described other species in the past. They
conducted fieldwork at night during the wet season in order to find the
easily overlooked animals.
"They mostly live in the leaf litter in the day... But at night they
climb up and then you can spot them," said Dr Glaw, explaining that the
animals moved up into branches to sleep. The scientists carefully
scanned the most likely habitats with torches and headlamps to find
roosting sites.
They found the smallest species on a remote limestone islet and believe it may represent an extreme case of island dwarfism.
This phenomenon occurs when a species becomes smaller over evolutionary
time in order to adapt to a restricted habitat such as an island.
According to Dr Glaw there could have been a "two-island effect" in the
case of B. micra. "It is possible that the big island of Madagascar has
produced the general group of dwarf chameleons and the very small island
has produced the tiny species," he told BBC Nature.
Varied but vulnerable
Because the chameleons looked similar in appearance, researchers
conducted a genetic analysis to confirm that they were indeed four
distinct species. The genetic differences between the species were
described as "remarkable" by team member Miguel Vences from the
Technical University of Braunschweig, Germany. "This indicates that they
separated from each other millions of years ago - even earlier than
many other chameleon species," he said.
Each of the new species was restricted to a very small territory, just a
single square kilometre for the smallest. "In Madagascar many species
are restricted to small habitats and that makes it important to conserve
them" said Dr Glaw. Scientists believe the small ranges of the species
make them especially sensitive to habitat disturbance.
B. tristis, named after the French word "triste" meaning sad, was found
in an isolated patch of forest close to an expanding city.
The team chose thought-provoking names as an expression of their concern for the future of the island's micro-endemic species.
Source :- http://www.unbelievableinfo.com/2013/12/worlds-tiniest-lizards-has-been-discovered-in-madagascar.html
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