Dinosaur paleontologists are investigators, piecing together ideas from pieces of fossils to understand what an entire organism appeared like, how it moved, and how it acted. While even a young child might inform you a Tyrannosaurus’ sharp teeth assisted it consume meat, more subtle proof—from microwear on a tooth to the shape of a jaw muscle accessory website—has actually assisted researchers paint an abundant image of the ancient animals’ capability to obtain and take in food.
In “An Illustrated Guide to Dinosaur Feeding Biology,” to be released by Johns Hopkins University Press in June, paleontologists Ali Nabavizadeh, a scientific assistant teacher of biomedical sciences at Penn’s School of Veterinary Medicine, and David B. Weishampel, teacher emeritus at Johns Hopkins University’s School of Medicine, provide a sequential narrative tracing more than a century of findings associated with how and what dinosaurs consumed. The book “is very much a synthesis of all of the research that’s ever been done in dinosaur feeding, since practically the beginning of dinosaur paleontology,” Nabavizadeh says.
The authors’ objective was to trace the arc of discovery, showing how each insight built on those previous or sometimes challenged old beliefs. “It was important to me to include everyone’s research that we could,” Nabavizadeh says, “trying to make it as strictly objective as possible.”
The result is a 353-page, 14-chapter chronicle of paleontologic discovery, with 250 illustrations, lots of in full-color, to drive home the info. The authors hope it will be an important resource to scientists and trainees thinking about dinosaurs and animal researchers thinking about feeding anatomy and biology, in addition to one with attract “any dinosaur enthusiast,” Nabavizadeh says.
Anatomy lessons
Nabavizadeh started his undergraduate research studies at the University of Kansas on a pre-med track, however, after enrolling in zoology and paleontology, understood that anatomy was what caught his attention and composed his undergraduate thesis on dinosaur feeding habits.
He pursued a doctorate in practical anatomy and advancement at Johns Hopkins, where he fulfilled Weishampel. The connection created Nabavizadeh’s connection to Penn, as Weishampel was the very first doctoral trainee to study under Penn paleontologist Peter Dodson, teacher of anatomy emeritus, a prominent dinosaur paleontologist.
“I went on to work with Dave for five years and did my dissertation with him,” Nabavizadeh says. His doctoral research study took a look at the variety of cranial structures—jaw muscles, teeth, beaks, and more—in a group referred to as ornithischian dinosaurs, that includes most herbivorous dinosaurs, consisting of renowned types like Stegosaurus and Triceratops.
It was as Nabavizadeh was concluding his Ph.D. that he and Weishampel created the concept of a book on feeding habits. They’ve because worked for almost a years to bring it to fulfillment.
Charting a century-plus of discovery
Nabavizadeh and Weishampel begin the book with a history of crucial researchers and crucial findings in the field. A chapter on basic dinosaur anatomy follows, then from there each of 10 chapters concentrates on a various dinosaur group, adequately communicating how years of research study have actually led us to the existing understanding of the animals’ feeding biology. A last chapter goes over paleoecology and dinosaurs’ location in the communities they populated.
Some of the earliest research studies, from the 19th century, relied mostly on the morphology of fossil jaws and teeth to figure out dinosaur types dietary choices and habits. Later, other elements of an animal’s anatomy entered into play.
“The claws and limbs and tails could help answer questions like, Would they run after prey? How might they hunt and capture other animals?” Nabavizadeh says.
More just recently, tooth wear has actually ended up being a crucial source of info on dinosaur diet plans. “You can see a lot of scratches and pits and gouges on the teeth of these dinosaurs, which is fascinating, because you’re essentially looking at their last meal, because their teeth are constantly being worn down,” he says. “And from there you can say things like, What direction were their jaws moving? What types of foods were they eating? Was it a tough material? Was it a soft plant material?”
Paleontologists and anatomists can likewise count on marks on fossils that show where muscles connected to acquire info about how an animal’s jaw moved. A blossoming instructions for the field is to integrate sophisticated innovation, such as computer system modeling and limited component analysis, to design how bones and soft tissues would have collaborated and enabled various kinds of movement.
“Modeling has turned up a lot of surprises in what we know about the movements of the jaw,” Nabavizadeh says.
Another essential of picturing how the physiological structures caught in fossils might have when moved living dinosaurs is relative anatomy. Paleontologists aim to animals that wander Earth today and share ancestral tree connections to dinosaurs to form hypotheses about their motions and routines.
“We know birds are living dinosaurs; they’re a very specialized version of the dinosaur,” he says. “But you also have things like crocodiles and lizards that you can look at to consider their cranial hump, their muscle morphology, the sites of muscle attachment to the skull,” he says. “You can look at the evidence in the fossil record and say, OK, well, there’s a muscle scar here where we also see a muscle attachment in this lizard, and so we compare it back.”
Visual knowing and open concerns
Right in the book’s title is a tool that Nabavizadeh depends on to learn brand-new physiological ideas: illustration. When he was a college student at Johns Hopkins, he was pleased to discover that the university housed a medical illustration program.
“I got to know the professors, and they allowed me to audit courses,” he says. “That was kind of my track into illustration. It’s kind of secretly my favorite part of what I do.”
Nabavizadeh himself drew all the dinosaur illustrations in the book, showing how, for instance, jaw muscles may connect to the skull, or which parts of a dinosaur’s anatomy assistance its biomechanics.
“I love drawing. It helps me learn; it helps me teach,” he says.
Despite Nabavizadeh and Weishampel’s detailed method, the field is awash in unanswered concerns. On a microlevel, for example, Nabavizadeh wish to understand more about the exact plant types some herbivores were consuming and what physiological structures in their skull they utilized to squash food. On a more comprehensive environmental level, more research study is required to comprehend how their feeding habits affected the other types—both plant and animal—that shared dinosaurs’ environments, and how each sculpted its own specific niche in order to prosper.
“We present a lot of evidence in the book,” Nabavizadeh says, “but there’s always more to find out.”