We might think these animals would be quite large, given that their plesiosaur descendants are quite large animals. However, many of these nothosaurus are extremely small, ranging from 15-30 cm (6-12 in) in length. There are individuals known to reach 2.7m. Despite the long neck and tail that we see in illustrations of Keichousaurus, that long neck is actually quite short, in respect to what we usually think of for long-necked animals (think of giraffes and long-necked dinosaurs, as examples). Of course, that neck is relatively long for these small animals!