By Maxwell Yeager, MFA
and collaboration and advisory from
Ali Nabavizadeh, PhD Postdoc, University of Chicago
Comparative anatomy is an important science to understanding the biodiversity and evolution of animals. However, current visualizations of exotic animal anatomy and biology, especially that of extinct life, is limited in terms of detail, volume and understanding.
This is especially true for dinosaurs.
As more is uncovered about these creatures, paleoartist produce a glut of fanciful illustrations of colorful feathered dinosaurs in conceptualized environments On the other hand, research and referential materials are limited to purely flat, diagrammatic and simple drawings. I think it is important to strive for a marriage of these two approaches, thereby creating clear and accurate anatomical representations of dinosaurs while also incorporating  the textures, color and volume that are the hallmarks of favored referential and educational anatomy material. As a medical Illustrator, I understand that it is our role to not only provide accurate visuals, but also visuals that will actively engage the viewer. I believe that the illustration of dinosaur soft and hard-tissue anatomy from a medical illustrator’s approach would benefit the paleontological community and those wanting to learn about these amazing creatures as a whole.
Award of Merit at the 2016 AMI Conference Salon
Student Section
Anatomical, Pathological
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Click to view each illustration at full size.
Specifically, my research and goal is to explore and artistically represent the jaw muscles of different Theropod dinosaurs and their extant relatives in order to visually describe the morphological differences and similarities in this family tree. One of the most distinctive structures of any vertebrate animal is their skull. Ultimately the shapes and structures of skull can not only be used to deduce evolutionary closeness, but also used to interpret function and offer a great deal of insight about an animal’s behavior, adaptations, diet and lifestyle in general. Naturally, the bony structures of the skull also indicate the unfossilized tissues of the muscles and can be used to imagine the faces of long extinct organisms. Additionally, it is my goal to further a lay audiences' understanding of what these dinosaurs relationships with extant animals are.
What is a theropod?
A theropod is a member of a suborder of dinosaurs called Theropoda, from the Greek "Wild beast foot". They first appeared in the late Triassic period 231.4 million years ago and were ancestrally carnivorous. Primarily recognized as bipedal super predators, like tyrannosaurs, the family further diversified to fit herbivorous, omnivorous and insectivorous niches. Evidence shows that birds evolved from small theropods and are actually the only surviving descendants of the dinosaurs . Features linking theropods to birds include a furcula (wishbone), air-filled bones, nesting behaviors and feathers. Though not all theropods are proven to have had feathers by means of fossilized imprints, it can be inferred that many of them did, especially the coelurosaurs, a group directly linked to birds that even included Tyrannosaurus rex.
On the other hand, Alligators are related to the common ancestor of dinosaurs, branching off much earlier around 250 million years ago. While still surviving to this day, they provide an alternative look at the origins of dinosaur and reptile morphology in contrast to birds being the most evolved derivative.
What do their muscles have to do with this?
Like any part of an animal's body, the skull, and the muscles it houses, serve a function. Just looking at the shape of the skull, and the teeth it had, a lot can be inferred about the animal's diet and lifestyle. Small, peg like teeth may be good at stripping branches of leaves while a log snout filled with sharp teeth may be good at slicing through flesh.
Similarly, the skull can tell us something about the musculature too. Like a forensic artist, surfaces of the skull can help to indicate the shape and attachment of muscles and thusly better indicate the face of the animal. This is key to bringing them to life metaphorically.
How did you know what colors to make them?
I didn't! Because we cannot directly observe extinct animals, a paleoartist's job is to make educated guesses about aesthetic choices like this. However, even something like color selection of the skin, scale and plumage of an animal can have huge implications about their lifestyle. When making these decisions, it is best to consider their habitats, lifestyles and what animals in the present day best fill the niches they might have had. For example, Tyrannosaurus rex was the top predator of it's environment, much like a bear or lion, and probably had more muted, earthy tones while velociraptors were found in the Gobi desert of Mongolia and would have to blend into the then sandy and rocky environment as an ambush predator.