Their synapomorphies include the possession of a long nasal bone, stretching to the front beyond the nostril; large scleral rings, filling the eye sockets; a narrow snout in top view; and converging digits with little space between them.
12.
Comparisons between the scleral rings of several sauropodmorph genera ( " Diplodocus ", " Lufengosaurus ", " Nemegtosaurus ", " Plateosaurus ", and " Riojasaurus " ) and modern birds and reptiles suggest that they may have been cathemeral, active throughout the day at short intervals.
