Titanosaur
A large titanosaurid nesting ground was discovered in Auca Mahuevo, in Patagonia, Argentina. Another colony is reported in Spain. Several hundred female saltasaurs dug holes with their back feet, laid eggs in clutches averaging around 25 eggs each, and buried the nests under dirt and vegetation. The small eggs, about 11–12 cm (4–5 in) in diameter, contained fossilised embryos, complete with skin impressions. The impressions showed that titanosaurs were covered in a mosaic armour of small bead-like scales. The huge number of individuals suggests herd behavior which would have given protection against large predators such as Abelisaurus. Their primary protection was, of course, their size. It is difficult to imagine a predator tackling a fully-grown titanosaur, and probably none did. Young titanosaurs would need guarding, of course.