The fossilized skulls of two new species of large, meat eating amphibians have been discovered by researchers in the Sahara desert of Niger in West Africa. The fossils are believed to be 250 million years old - the first and oldest amphibious carnivores found in the arid, low-lying region. Until they saw these fossils, scientists had believed animals like these had gone extinct 40 million years earlier, around 290 million years ago. Seven organizations from five countries cooperated in this research, which is reported today in the journal "Nature." The lead scientists from Niger are Dr. Oumarou Ide and Dr. Abdoulaye Maga of the Institut de Recherches en Sciences Humaines in Niamey.