Input (grade 10): Ichthyosaurs averaged 2 - in length (although a few were smaller, and some species grew much larger), with a porpoise-like head and a long, toothed snout.
Output (grade 5): Ichthyosaurs averaged about 2 â "4m (6 â" 13ft) in length; a few were smaller, and some species grew much larger. They had a porpoise-like head and a long, toothed snout.