Episode 12 Field Guide: Growing up Dinosaur!
When we think of iconic dinosaurs, like T. rex with its massive head full of teeth, and Parasaurolophus crowned with a gigantic, tube-like crest, we’re thinking of the features of adult dinosaurs. But we know from looking around today that animals change a lot from birth to adulthood. Did T. rex always have a massive maw and Parasaurolophus a huge crest? How quickly did they grow in? What were they used for? To really understand the biology of these titans, paleontologists need to study baby dinosaurs to connect the dots from tiny hatchling to adult dinosaur. Unfortunately, the fossils of dino-toddlers are few and far between because their skeletons are usually pretty delicate. Plus, it can be very hard to tell what species of baby dinosaur you’ve discovered. In this episode we discuss the improbable discovery of a baby Parasaurolophus with Dr. Andy Farke, a paleontologist from the Raymond Alf Museum and Webb Schools in Clermont, California. Dubbed “Dinosaur Joe”, the young dinosaur was found and studied by young, high school scientists from the Webb School. The high school scientists were part of the team that revealed the six-foot-long animal was only one-year-old and had a little nubbin of a what would become that spectacular Parasaurolophus crest. Listen to the episode to learn more about growing up dinosaur!
The best way to listen to the episode is to subscribe to the podcast on iTunes or you can download or stream the episode by following this link. For images and more details about the discovery of Dinosaur Joe and the science behind the early years of dinosaurs, click below!
A few links for easy reference after listening to the episode. Skip after the links for images of the fossils and the people who studied them!
Parasaurolophus – The tube-crested dinosaur we focus on in this episode. Parasaurolophus could get to the length of a school bus (about 45 feet) and as an adult it supported a huge, hollow crest that connected to its mouth and nose and could have given this duck-billed dinosaur a resonant call.
Duck-billed dinosaurs – Technically called hadrosaurs, these herbivores had broad, toothless beaks at the front of their faces which were covered in the same material that covers modern duck beaks. At the back of their jaws, hadrosaurs had cropping teeth that would have made them formidable herbivores.
Kaiparowits formation – Layers of rock found in Grand Staircase-Escalante National Monument in Southern Utah. The Kaiparowits formation was laid down between 83 and 72 million years ago during the Late Cretaceous period. Other dinosaurs from the formation include the 15-horned dinosaur Kosmoceratops (also discovered and described by Dr. Farke) and Teratophoneus, a relative of Tyrannosaurus rex who we talked about in this episode of Past Time.
Ontogeny – The study of how an organism grows up (it literally means “the origin of being”). This field includes scientists who study embryos and scientists who study how adult features – like horns, brow-ridges, and colorful features – develop. In this study, Sara Werning of Stony Brook University examined the bones of Dinosaur Joe to figure out how old he was.
Raymond M. Alf Museum of Paleontology – The museum where Dr. Farke works in Clermont, California. It’s the only nationally accredited fossil repository in the country on a high school campus, which means the students at the Webb Schools get to work with paleontologists like Dr. Farke.
Big Questions from Little Animals
Dinosaurs could get huge, like the gigantic, long-necked sauropods, and dinosaurs could get weird, like the spiky relatives of Triceratops, and dinosaurs could get terrifying, like the toothy relatives of Tyrannosaurus rex. But how did they get so big, spiky, and toothy? How long did that take and what were all the accessories used for?
These are all real biological questions scientists ask today when they study the size of elephants, the antlers of deer, and the sharp teeth of lions. The key to understanding the importance of these traits is understanding when these features occur as the animal grows up. It might seem obvious that an elephant uses its size to fend off predators and eat food other animals can’t reach, but how quickly do elephants grow to gigantic sizes? How much energy does it take to get big? How do teenage elephants avoid predators and eat when they are only half the size they will be when they are adults?
The process by which an animal changes as it gets old is ontogeny. And for paleontologists who want to understand the life history of dinosaurs – when size, spikes, and teeth grow in – it can be tough because we have a slightly skewed fossil record. Big bones fossilize relatively easily because it takes a lot of erosion to break them down. Dinosaur eggs aren’t common, but they do have a chance of becoming part of the fossil record because dinosaurs needed to lay them on the ground. But the small, delicate bones of nimble juvenile dinosaurs break up quickly. Special conditions are necessary for any animal to become part of the fossil record, but they need to be even more special to preserve the young guys. But the questions they can answer about the timing and purpose of amazing features is worth the hunt.
Past times at Webb High
Fortunately, hard-working paleontologists can get lucky and discover these juvenile dinosaurs that offer us a glimpse into the life history of a dinosaur. Our guest in this episode is Dr. Andy Farke, a dinosaur paleontologist at the Raymond M. Alf Museum of Paleontology in Clermont, California. Dr. Farke is also a teacher at the Webb Schools, a college-prep school that share the Alf Museum’s real estate. Throughout the year, Dr. Farke works with high school students on paleontological research, and he takes some of them into the field to search for more fossils each summer. He’s also a graduate of Stony Brook University, where Matt and Adam study currently. Go Sea Wolves!
Back in the summer of 2009, a recent graduate of the Webb Schools, Kevin Terris, found an unassuming fossil fragment near a large boulder. Dr. Farke would normally have dismissed the featureless piece of bone, but he happened to flip over another small rock…and saw the face of a baby dinosaur. The rest of the expedition gathered around as the rock Kevin found was cleaned up and Dr. Farke recognized the small foot of a duck-billed dinosaur. One end of the boulder had the head, and the other end had the foot. Inside there must be a skeleton!
The boulder was tucked far from any access road in Grand Staircase-Escalante National Monument in Southern Utah in the Southwestern United States so Kevin’s discovery needed to wait until the following summer when the Alf Museum’s team could bring in a helicopter to airlift the boulder to a waiting truck.
Back in the lab, the delicate specimen could be carefully removed from the surrounding rock and the skull could be scanned. Collaborating with Webb students Derek Chok, Annissa Herrero and Brandon Scolieri, and Stony Brook paleontologist Dr. Sara Werning, the baby dinosaur skeleton was finally published in a scientific article and given an extensive website for the general public.
Dinosaur Joe: The Baby Parasaurolophus
Or, how to grow a trombone on your face
The baby dinosaur Kevin found, nicknamed Dinosaur Joe, was a young individual from the dinosaur genus Parasaurolophus. The larger group Joe belonged to was the hadrosaurs, or “duck-billed” dinosaurs. These medium-to-huge herbivores had a wide bill that was covered in a sheath of keratin, like modern bird beaks. This beak-covering is actually preserved in the beautiful fossil that is Dinosaur Joe. In the back of a Parasaurolophus’‘s mouth were rows of tiny teeth that made short work of any vegetation the animal consumed.
But the most striking feature of Parasaurolophus was the elaborate crest sticking off the back of their heads. At first glance it might look something like a unicorn horn, but the inside was hollow like a dinosaur version of a trombone. The whole structure is actually made up of the nose bones which are pulled back over the head to create a complex resonance chamber. The close relatives of Parasaurolophus had hollow crests, too, but these were different shapes and would have given the animal a different profile and a different sound. Paleontologists have actually created this resonance chambers and simulated the sounds of these extinct dinosaurs. Listen to the podcast to hear what a duck-billed dinosaur might have sounded like!
But Dinosaur Joe didn’t have a long, trombone-like tube: instead, he had a short air passage that Dr. Farke and his collaborators were able to reconstruct using medical scanner to create a three-dimensional model of the inside of Joe’s little crest. During the course of Joe’s life, this crest would have elongated into its adult shape.
Of course, the researchers working on Dinosaur Joe also wanted to know how old their little dinosaur was and how long it took for the animal to grow. It was already over six feet long when it died, but it had about forty feet yet to go. How long did it take to get six-feet long?
This is where Dr. Sara Werning, a paleontologist at Stony Brook University, came in. She is an expert on animal growth. She usually slices open the bones of animals and looks at the arrangement of the bone cells to figure out how quickly the bone was made and how long the bone had been growing. Dinosaurs (and many other types of animals) lay down a solid ring of bone each year. By carefully examining these rings, Dr. Werning is able to figure out the age of a dinosaur, like this five-year-old relative of Parasaurolophus named Tenontosaurus pictured on the right (photo taken from dinosaurjoe.org):
When she looked at the bone of Dinosaur Joe, she didn’t see any nicely laid out rings. Instead there was a chaotic mash of bone cells that indicated this six-foot-long dinosaur was under one-year old and was growing really quickly. Six feet, and already the size of a large pig, in under a year is a crazy growth rate which means Joe was using a lot of energy to grow up that fast.
The discovery of Dinosaur Joe continues the paleontological quest to understand how dinosaurs, with all their weird features, grew from small eggs to some of the largest animals ever on this planet. There are plenty of fossils yet to discover of juvenile and adult dinosaurs, and plenty of research to do with specimens that have already been found, like Dinosaur Joe!
If you would like to get involved in a fossil discovery, contact your local museum or historical society to see if you can become part of their research program. There’s a lot of time and a lot of animals out there and plenty of room for more curious minds!
Further reading for a broad audience:
The Dinosaur Joe website created by the Alf Museum and Webb Schools goes into all kids of great detail about the discovery and science behind the baby dinosaur. Seriously, a better website publicizing a dino-discovery has never been made. There are pictures, three-dimensional models, videos…we could go on all day! Dinosaur Joe’s Website
For further information on dinosaur eggs and babies, check out the classic Maia: A Dinosaur Grows Up by Dr. John Horner. The book details the trials and tribulations of baby Maiasaura, another duckbill dinosaur known from an amazing nest site in Montana. http://www.amazon.com/Maia-A-Dinosaur-Grows-Up/dp/0894716913
Further reading for a technical audience:
This fossilized baby Parasaurolophus was published in a technical research article which is freely available to anyone who wants to know the details about this specimen. Here is the link to the article and here is the citation:
(2013) Ontogeny in the tube-crested dinosaur Parasaurolophus (Hadrosauridae) and heterochrony in hadrosaurids. PeerJ 1:e182http://dx.doi.org/10.7717/peerj.182
For information on baby Triceratops specimens:
Goodwin, MB, Clemens WA, Horner JR, and Padian K. (2006) The smallest known Triceratops skull: new observations on ceratopsid cranial anatomy and ontogeny. Journal of Vertebrate Paleontology 26:103–112.
For information on a baby tyrannosaur (Tarbosaurus) from Mongolia that Adam sadly forgot to mention:
Tsuihiji T, et al. (2011) Cranial osteology of a juvenile specimen of Tarbosaurus bataar (Theropoda, Tyrannosauridae) from the Nemegt Formation (Upper Cretaceous) of Bugin Tsav, Mongolia. Journal of Vertebrate Paleontology 31:497–517.
Filed under: Baby Dinosaurs, Bone Histology, California, Cretaceous, Dinosaur Joe, Dinosaur behavior, Dinosaurs, Discovery, Field Guide, Fieldwork, Finding fossils, Fossils, Growing Up, North America, Ontogeny, Paleontology, Parasaurolophus, Podcast, Raymond Alf Museum, Triceratops, Utah, Webb Schools