The big dinosaurs get all the love. I’m not even talking about the endless “my sauropod is bigger than yours” contest, or the constant effort to one-up Tyrannosaurus rex. I mean that for any given species, we’re obsessed with the biggest individual. That’s always held up as a fossil exemplar, and, from a museum perspective, if you’re going to mount a dinosaur, why not a big one?
And given that dinosaurs generally lived fast and died young, those old, super-big individuals are pretty hard to find. But we often forget the other gap in our knowledge all the way at the other end of a dinosaur’s life.
Dinosaur babies are very rare. Even for well-sampled species, hatchlings and yearlings are seldom seen. Think of Triceratops and Tyrannosaurus, for example. They’re famous dinosaurs known from dozens of individuals each, but there’s only been one itty bitty baby published for each of these Cretaceous celebrities. For most dinosaur species, we haven’t yet found infants.
The discovery of any baby dinosaur, therefore, is a reason to thank our luck that the fossil record has safeguarded the rarity since the Mesozoic, and a new paper from Leonard Dewaele and colleagues gives us just such an occasion to celebrate.
Saurolophus angustirostris is one of those dinosaurs that’s known from a pretty good sample. Found in the Gobi Desert’s Nemegt Formation, this duck-faced herbivore is known from various sub-adult and adult individuals. The babies have remained elusive, however, no thanks to poachers.
The block at the center of the new study from Dewaele and colleagues was stolen from a Mongolian locality called “The Dragon’s Tomb” sometime during the 20th century and moved through private collections in Japan and Europe. Thankfully, however, in 2013 the fossils were donated to the Royal Belgian Institute of Natural Sciences in Brussels before being repatriated to Mongolia. Now that the block has a proper home in a museum, the story of the baby Saurolophus can be told.
At least three baby hadrosaurs are buried in the block, entombed with bits of eggshell that once surrounded them. That’s a lucky break. This simple association will help paleontologists identify other Saurolophus eggs in the future now that bones and eggs have been found together. And the little dinosaurs are tiny compared to the adults. The skulls of the incubating Saurolophus are only about 5% the length of the largest known for their species—adults could reach almost 40 feet in length. Even big dinosaurs started small.
Whether or not the little Saurolophus had pushed their way out of their eggs yet isn’t clear. They died when they were “perinatal,” or around hatching age.
What we do know is that they would have been adorable. These little dinosaurs weren’t copies of their parents, but awkward little critters with big heads, large eyes, and, inside, many of their bones were still fusing. Their saurian kind might have ruled the world, but these Saurolophus were tiny squeakers that probably tottered around the nest for a while before exploring the wider Cretaceous world. It may be strange to say given the group’s reputation as the “terrible lizards,” but dinosaurs started life cute.
Reference:
Dewaele, L., Tsogtbaatar, K., Barsbold, R., Garcia, G., Stein, K., Escuillie, F., Godefroit, P. 2015. Perinatal specimens of Saurolophus angustirostris (Dinosauria: Hadrosauridae), from the Upper Cretaceous of MongoliaPerinatal specimens of Saurolophus angustirostris (Dinosauria: Hadrosauridae), from the Upper Cretaceous of MongoliaPerinatal specimens of Saurolophus angustirostris (Dinosauria: Hadrosauridae), from the Upper Cretaceous of Mongolia. PLOS ONE. doi: 10.1371/journal.pone.0138806
Top image:
Bell, P. 2012. Standardized terminology and potential taxonomic utility for hadrosaurid skin impressions: a case study for Saurolophus from Canada and MongoliaStandardized terminology and potential taxonomic utility for hadrosaurid skin impressions: a case study for Saurolophus from Canada and MongoliaStandardized terminology and potential taxonomic utility for hadrosaurid skin impressions: a case study for Saurolophus from Canada and Mongolia. PLOS ONE. doi: 10.1371/journal.pone.0031295
Go Further
Animals
- Octopuses have a lot of secrets. Can you guess 8 of them?
- Animals
- Feature
Octopuses have a lot of secrets. Can you guess 8 of them? - This biologist and her rescue dog help protect bears in the AndesThis biologist and her rescue dog help protect bears in the Andes
- An octopus invited this writer into her tank—and her secret worldAn octopus invited this writer into her tank—and her secret world
- Peace-loving bonobos are more aggressive than we thoughtPeace-loving bonobos are more aggressive than we thought
Environment
- Listen to 30 years of climate change transformed into haunting musicListen to 30 years of climate change transformed into haunting music
- This ancient society tried to stop El Niño—with child sacrificeThis ancient society tried to stop El Niño—with child sacrifice
- U.S. plans to clean its drinking water. What does that mean?U.S. plans to clean its drinking water. What does that mean?
- Food systems: supporting the triangle of food security, Video Story
- Paid Content
Food systems: supporting the triangle of food security - Will we ever solve the mystery of the Mima mounds?Will we ever solve the mystery of the Mima mounds?
History & Culture
- Strange clues in a Maya temple reveal a fiery political dramaStrange clues in a Maya temple reveal a fiery political drama
- How technology is revealing secrets in these ancient scrollsHow technology is revealing secrets in these ancient scrolls
- Pilgrimages aren’t just spiritual anymore. They’re a workout.Pilgrimages aren’t just spiritual anymore. They’re a workout.
- This ancient society tried to stop El Niño—with child sacrificeThis ancient society tried to stop El Niño—with child sacrifice
- This ancient cure was just revived in a lab. Does it work?This ancient cure was just revived in a lab. Does it work?
Science
- The unexpected health benefits of Ozempic and MounjaroThe unexpected health benefits of Ozempic and Mounjaro
- Do you have an inner monologue? Here’s what it reveals about you.Do you have an inner monologue? Here’s what it reveals about you.
- Jupiter’s volcanic moon Io has been erupting for billions of yearsJupiter’s volcanic moon Io has been erupting for billions of years
- This 80-foot-long sea monster was the killer whale of its timeThis 80-foot-long sea monster was the killer whale of its time
Travel
- How to plan an epic summer trip to a national parkHow to plan an epic summer trip to a national park
- This town is the Alps' first European Capital of CultureThis town is the Alps' first European Capital of Culture
- This royal city lies in the shadow of Kuala LumpurThis royal city lies in the shadow of Kuala Lumpur
- This author tells the story of crypto-trading Mongolian nomadsThis author tells the story of crypto-trading Mongolian nomads