by a pattern of smaller plates. The large osteoderms contained some hollow spaces for blood vessels and spongy trabecular bone, while the small ones were solid. Patches of skin from unidentified Cretaceous titanosaurs have revealed similar scale patterns in embryos (a large scale surrounded by ten smaller ones) but no bone or mineralized structure, suggesting that, like crocodiles, those saltasaurids that possessed armor only developed it some time after hatching. Analysis of the osteoderms of the titanosaur Rapetosaurus revealed that the bones were hollow in adults, while those of juveniles were solid pieces similar to those in crocodiles. Paleontologist Kristina Curry Rogers, who made this discovery, theorized that the adult animals used their hollow osteoderms to store minerals during lean times. It is unknown whether any of the Saltasauridae used their osteoderms in a similar manner. Reproduction and development The same Argentine dig site, Auca Mahuevo, that provided information on embryonic skin, has also yielded information on the nesting habits of titanosaurs, but not saltasaurids specifically. The nests were constructed on the surface by piling debris in a ring around the eggs, with the eggs themselves left uncovered. Each egg was porous and spherical, about 14 cm in diameter, and they were laid in clutches. The embryos show smaller rostrum and nares close to the anterior portion of the face compared to adult titanosaurs, suggesting that the nostrils may have moved towards the back of the head as the animal grew. References Lithostrotians Prehistoric dinosaur families