1.   Dinosaurs were warmblooded, colorfully marked, gregarious creatures that made terrifying noises but nurtured their young and finally died out when the Earth was hit by a comet.

2.   The mothers never nurture their young, no matter how many litters they bear.

3.   They nurture the young and care for the old.

4.   They were apparently smart enough to live in family groups, with adults nurturing their young.