Complex sentence: Reports of giant anacondas date back as far as the European colonization of South America, when sightings of anacondas upwards of 50 meters (164 feet) began to circulate amongst colonists, and the topic has been a subject of debate ever since among cryptozoologists and zoologists.
Split into simpler sentences: Reports of giant anacondas date back as far as the European colonization of South America, when sightings of anacondas upwards of 50 meters (164 feet) began to circulate amongst colonists. The size of the largest anacondas has been the subject of debate ever since among cryptozoologists and zoologists.