We may not be able to directly observe them (with the obvious exception of Baby Sinclair), but newborn dinosaurs have given paleontologists around the globe magnificent insight into how these amazing creatures grew, lived, and reproduced nevertheless. Here are some of the most striking discoveries.
Compelling evidence in the fossilized remains of embryonic Lufengosaurus (a species of long-necked Chinese herbivore) suggests that at least some unborn dinosaurs kicked and wriggled prior to breaking free of their shells, activities which stimulate bone growth in modern-day mammals and birds.
According to some experts, a juvenile Scipionyx (which was later nicknamed “Ciro”) may have been less than three weeks old when it perished some 113 million years ago in what’s now southern Italy. Its remains are so spectacularly preserved that joints, ligaments, and even internal organs are visible (including the stomach, which shows that Ciro was rather fond of smaller reptiles and the occasional fish), making the little creature one of the most complete dinosaur specimens known to science.
A positively adorable baby Triceratops skull discovered in 2006 helped complete a study on the iconic dinosaur’s growth patterns which yielded some surprising results (you can see the various phases here) as paleontologist Jack Horner explains in this eye-opening TED talk (skip to the 13:05 mark):
When the opossum-sized Repenomamus robustus was first unearthed in 2000, the remains of an infant Psittacosaurus were found in its gut. For a dramatized recreation of its dino-guzzling antics, click here.
At over 11 feet in length, hefty serpents like Sanajeh indicus apparently had little difficulty invading the unguarded nests and eating the young of even the largest dinosaurs, as evidenced by a skeleton that was found coiled around a group of Titanosaur eggs back in 2010.
Known only from the fossilized carcass of a 28-inch hatchling, the species named Sciurumimus—or “squirrel mimic”— grew a layer of downy, feather-like structures on its tail at an early age, though it’s not likely that the pint-sized predator also went around collecting acorns.
The tennis-ball-sized footprints have been attributed to the dinosaur formerly known as Brontosaurus: Apatosaurus ajax, a massive herbivore which would have easily weighed in at over 20 tons when fully-grown. Curiously, these miniature tracks imply that their maker was running on its hind legs at the time, a feat its gargantuan parents most definitely couldn’t pull off.
Hatchling hadrosaurs (aka “duck-bills”) faced a particularly jarring challenge. A lack of any obvious defense mechanisms such as horns or plated armor is an unenviable situation for any potential prey item, but a 2008 study found that the seemingly-helpless animals defended themselves by simply outgrowing their predators, sometimes reaching full size at three to five times the rate of local Tyrannosaurs.
Egg-laying can be a sneaky business. Rather than go through the effort of raising their own young, some modern birds such as the European Cuckoo simply deposit theirs in the nest of unsuspecting songbirds to trick the unwitting victims into feeding and nurturing the crafty avian’s young.
While it’s a speculative conclusion, Mark Norell of the American Museum of Natural History has turned to this Machiavellian strategy as a potential explanation for why a pair of Velociraptor-like hatchlings (or possibly embryos) were found in an Oviraptor’s nest (though Norell also offered some more conservative conclusions, such as that the mother simply made a snack of the two raptors).