Several baby dinosaurs had horrific, short lives, suggest their remains, which were recently discovered still in their nest where they all died approximately 70 million years ago.
Little did they know, however, that their remains would one day help paleontologists to better understand the growth stages of their species, Saurolophus angustirostris, aka "Ridged Reptile" or "Lizard Crest."
The nest and its gory contents are described in the journal PLOS ONE.
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Lead author Leonard Dewaele told Discovery News that it is possible "the mother somehow went missing or died, and that the babies were incapable of finding their own food resources and of surviving."
They died one by one over a period of time, he said, "unable to disperse from their already-dead siblings."
Dewaele, of Ghent University and the Royal Belgian Institute of Natural Sciences, explained that the condition of the dinosaurs' fossils provides evidence for this way of dying, revealing that "the babies were at different stages of decomposition at the time of burial."
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The burial took place at the appropriately formidable sounding "Dragon's Tomb" site located in Mongolia. Dewaele said that, during the Late Cretaceous, the landscape was a vast plain intersected by numerous rivers, one of which washed over the dead baby dinosaurs.
"The sandy sediments in which the babies were buried lead us to assume that the nest was located on a river bank, or point bar, and got buried by sediment when water levels rose" during the wet summer season, he explained.
Paleontologists have long suspected that juvenile dinosaurs often looked very different from their adult counterparts, and not just because of their size differences, with these remains supporting that belief.
Large, plant-eating "Lizard Crest" is famous for its head crest that looks like a spike was rammed into the top of the dino's head. The babies had no such thing, but the researchers did find, as Dewaele described, "a very small, virtually nonexistent supra cranial crest." In short, the dino babies had the beginnings of the crest, but it would not yet have been visible to onlookers.
This suggests that the crest held some function that could have been useful for adults, such as for mating rituals, defense or identification among their own kind.
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The baby dinos also had bigger eyes than the adults did, relative to the rest of their facial features. Dewaele said that is true for most animals, even today. It is one reason why we tend to like babies so much, as the innocent wide-eyed look often grabs our attention.
The young dinos additionally had a short snout versus the longer ones of adults.
Taken together, the findings then add to the significant body of evidence that some, if not all, dinosaurs went through defined growth stages characterized by changes to their anatomy and appearance.
There's yet another story to tell about the nest and its babies. Co-author Pascal Godefroit informed Discovery News that the remains were originally poached, that is to say, illegally taken, "and kept in a private collection in Europe." They were subsequently given to the Royal Belgian Institute of Natural Sciences. The institute has since signed an official agreement that will allow this, and certain other poached items currently in Europe, to be brought back to Mongolia.