The Late Cretaceous Nesting Grounds of Patagonia.

Acrylics and inks on cardboard.
Originals in the travelling exhibition "Dinosaur Eggs" of Charlie and Florence Magovern.

Vast sauropod nesting grounds (with their typical spherical shapes and eggs the size of small soccer footballs) have been found recently in the Argentinean Patagonia. This double scene is inspired by the recent research of Luis Chiappe's team. The most intriguing aspect of the new research is that they have also discovered embryos and soft tissue with the eggs, showing for the first time the skin of a sauropod dinosaur about to be born. Skin of embryos has been the source of intense speculation: Were sauropods feathered or hairy too considering their probable high metabolism? Their rate of growth was probably unparalleled in the animal world (from a one to two kilograms hatchling to a probably fully grown 7 tons in seven years). This discovery points towards a scaly skin, although being embryos we could argue for a later development of insulatory coverage. The almost microscopic pattern of the skin shows very small non-overlapping mosaic scales surrounding slightly bigger ones: A perfect blueprint of what the adult titanosaur skin was going to be. As we know now titanosaurs are (among other things) famous for their armoured skin with rather large scutes surrounded by many small, pebbly, non-overlapping scales. The embryos show that incipient pattern too. A double row of scutes lined the whole back (most probably also neck and tail) and the rest of bigger scutes were scattered all over the trunk, hip and shoulders. Because intriguing smaller scutes have been found together with titanosaur remains from Morocco, I have also reconstructed the pattern extending well over the neck and tail. The armour evolved in different kinds of titanosaurs to sometimes extravagant excesses.
Saltasaurus lays eggs


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Chiappe's conclusion is that the titanosaur that laid the eggs was most probably Saltasaurus, a medium sized titanosaur. The first scene depicts the moment the saltasaurs lay the eggs and care and build the nests. The skull that served as basis for the head in the foreground is based on a well known titanosaur skull researched by famous paleontologist Rubén Martínez, from Comodoro Rivadavia ( in the Argentinean Patagonia) and it also incorporates Larry Witmer's new thoughts on the frontal facing dinosaur nostrils (that almost constituted a "trunk").
Saltasaurus hatch


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The second scene is the moment the first eggs start to hatch while the saltasaurs have retreated to guard the nests in the distance. The adults become distracted by an adult Aucasaurus (a smaller abelisaur relative of Carnotaurus), while juveniles aucasaurs have already passed the formidable barrier and started raiding the nests. For more information you may like to consult the book "Walking on Eggs" by Chiappe and Dingus.

 

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