Ancient frog found in Madagascar
Old branch in the family tree of amphibians threatened with extinctionRead out
In an amphibious inventory on Madagascar, scientists have come across a previously unknown frog species that they christened Tsingymantis antitra. In the "old frog from the karst massif", so the meaning of the scientific name, it is a genus that represents an old branch in the pedigree of frogs.
"We knew immediately that we had something very special in front of us, " explains Frank Glaw of the Zoologische Staatssammlung München, "because none of the 232 known Malagasy frog species resembled this animal." Only four females found the researchers of the new genus - and not in the dripping rainforest, but in a bizarre, cavernous dry limestone formation in the north of Madagascar. Glaw and Professor Miguel Vences, Technical University of Braunschweig, together with Professor Noromalala Raminosoa from the University of Antananarivo in Madagascar, had extensively studied this region.
Nowadays, it is no big deal for zoologists to discover new species of amphibians. Modern investigation methods such as sound analysis and DNA sequencing as well as the search in remote rainforests have brought the scientists almost a "frog species rain". But the discovery of Tsingymantis antitra is something special. For it is probably the most original representative of a group of frogs, almost exclusively in Madagascar, the subfamily Mantellinae.
This is also confirmed by genetic analyzes carried out by Simone Hoegg of the University of Konstanz and Vences. An extremely rare stroke of luck, since such old lines in the family tree are either long known or long extinct. How long the newly discovered frog species can survive is uncertain. Not only the rainforest, but also the forests in Madagascar's arid regions are being cut down.
Tsingymantis - a living fossil?
The find also provides important information on the climate history of Madagascar. The zoologists noticed that the most primitive frogs in Madagascar live mostly in drylands, although today almost all frogs live in the local rainforest. This observation coincides well with new hypotheses on the climate history of the island. display
Thus, the Malagasy rainforest could be younger than commonly thought - it may not have formed until the Oligocene, about 30 million years ago, in the course of the continental drift. After India had broken off from Madagascar and drifted off to the north, the Indian Ocean opened and brought up the damp trade winds that sprang up the rainforest. Fr sche, Cham leons, lemurs and countless other species created a new paradise, in which developed today's biodiversity. However, their ancestors may have needed to survive in a drier environment. The Tsingymantis, native to the cool fissures and caves of the arid limestone mountains, could be a living fossil that has maintained the lifestyles of the Malagasy frog ancestors.
Conservation on Madagascar
Although Tsingymantis occurs in a protected area, the very small size of its area of distribution is a threat. "Protection of this kind should therefore be given high priority, " emphasizes Miguel Vences, After all, the time seems ideal, because the Malagasy government wants to triple the nature reserves in the next few years. Recently German zoologists returned from a workshop in the Malagasy capital Antananarivo. Under the auspices of the local government, a strategy has been developed to protect the country's unique amphibian fauna.
The research sponsored by the Volkswagen Foundation has made a major contribution to determining how many species of frogs live on this island, where they occur and how they can be distinguished. "These data, " says Glaw, "provide an important basis for deciding which areas and species need to be protected most."
(idw - Volkswagen Foundation, 20.10.2006 - DLO)