In 1933 an incomplete fossil of Lariosaurus balsami, a nothosaurid from the Middle Triassic (circa 240 million years ago) of which the first example was discovered at Perledo, some 10 km north of Lierna, was found in a quarry in the frazione of Grumo. It is now in the Museo di Storia Naturale in the Palazzo Belgioioso of Lecco.[6]