Select the word that means features that are not shaped normally. In 1995, a discovery by a group of Minnesota children set off a major scientific investigation. In a local pond, the students found dozens of frogs with deformities such as extra limbs or missing legs. State officials and scientists from around the world began to study potential culprits. They investigated whether chemicals or radiation might be responsible, for example. After years of study, the answer remained unclear. Perhaps predators had been biting off the frogs' legs. The good news is that apart from a few isolated areas, most frog populations continued to be healthy. Scientists have said that they will continue monitoring the frogs.