Input (grade 4): The better known S. popularis species was around 15 m long, but a more recently discovered species, S. sikkanniensis, was longer still, at 21 m.
Output (grade 4): The better known S. popularis species was about 15 metres (50ft) long, but a more recently discovered species, S. sikkanniensis, was longer still, at about 21m (70ft).