Students hone observation and critical thinking skills in refreshed Earth Sciences course
For the past 20 years, Kent Kirkby has captivated large groups of freshmen in the lecture hall with vivid tales of dinosaurs and natural disasters. Occasionally, for that course, ESCI 1003, he’ll also wheel out a massive skull, fragments of fossil fish, or a baby mammoth tooth—to ooh–ahhs.
This spring, the Distinguished University Teaching Professor of Earth Sciences decided it was time to push himself as a teacher and challenge his students even more.
Kirkby has added a lab portion to “Dinosaurs and Our World,” previously known as “Dinosaur Evolution, Ecology, and Extinction: Introduction to the Mesozoic World.” The new course, designed for undergraduate non-geology and non-biology majors, features living animals, fantasy creatures, and extinct beasts—plus, their skeletons or extraordinarily detailed bone replicas.
Recently, ESCI 1003 was named among the “10 Coolest Classes at the University of Minnesota” by OneClass, a Canadian startup.
“In the past, I’d pass around some casts while I was talking or showing slides,” explained Kirkby, “but that wasn’t particularly effective because students only got a couple of seconds or minutes to handle something before they had to move it on.”
“With the dinosaur lab, students can now get more hands-on time—about two hours a week—and more chances to see and discuss what they’re looking at,” Kirkby said.
Typically, 1000-level Earth Science courses draw between 150 and 180 students. In contrast, Kirkby’s labs—held in the newly renovated Tate Hall—will allow students to work in teams of four.
Game of dragons
Of his 14 lab assignments, the one that’s sure to perk up some students—and, perhaps, baffle a few—is the exercise that comes with brightly colored, highly detailed dragons. Kirkby uses the eight-inch models to introduce cladistics.
This method of classifying animals and plants based on noticeable, common characteristic is often used when studying dinosaur relationships. According to the system, which was established in the 1950s, the more traits two species share, the more likely they are related and inherited the traits from a shared ancestor.
“Animal classification labs are typically rather boring and usually take one of two approaches,” said Kirkby.
“Cladistic labs usually use either modern animals, like a frog or cat, and ask students to classify them by ancestry; or they ask their students to classify imaginary organisms using paper drawings,” he explained. “In the first case, students already know the answer ahead of time and, in the second, there is typically only one ‘correct’ solution. I wanted to do something different.”
Kirkby gets his class to create a world of dragons.
“The students have to actually look at each physical dragon model and figure out how 15 of them fit together in an evolutionary sequence,” Kirkby said, of his cladistic lab.
“Sure, dragons aren’t real,” Kirkby said, “but make-believe allows us to speculate and not worry too much about making mistakes.”
Students can look at the models in front of them and begin to debate alternatives within 5 or 10 minutes of the lab,” he said.
For example, a hydra—or dragon with seven heads—would be more closely related to a two-headed dragon than one with a single head, according to cladistics. The same goes for fantasy beasts with wings that were adaptations of their forelimbs versus others who had wings that were functionally a third pair of limbs. Both groups may be flying dragons, but would represent different evolutionary lines or clades.
No ‘right’ answer
Since the activity is based on models that were not created with evolution in mind, there is not necessarily one “right” answer, which is something that Kirkby appreciates.
“With limited data, the dragons are a ‘messy’ data set, with more than one possible way to interpret their evolution,” he said. “That mimics the uncertainty of many real-world data sets.”
Once the students get the hang of classifying the fictitious dragons, they move on to dinosaur models and bones—delving into lifestyle habitsNo as well.
In fact, two lab sessions take students off campus, where they get to apply their newfound skills in interpreting animal lifestyles from body designs at Como Zoo and the Science Museum of Minnesota.
“When you look at toy models, bones, or casts, you can tell a lot about the animal and its lifestyle,” Kirkby said. “And when you start comparing them, you’ll start to notice there are differences.”
According to him, plant eaters are easy to distinguish. Just look at the animal’s hips.
“For bulk plant eaters, the wider the hips, the bigger the gut,” Kirkby said. “And a large gut is necessary because plants are more difficult to digest than meat.”
“You don’t even have to look at the animal’s teeth, which is good because skulls are often missing in fossil finds.” he explained. Instead, look at the width of the animal’s hip or the arch of its ribs and you can make a reasonable interpretation of its diet.”
In a similar manner, students can interpret an animal’s speed from the proportions of its limb bones or from measuring the tracks it left behind in soft sediment.
Making a lasting impact
Ultimately, Kirkby—who has been enamored with dinosaurs since receiving his first plastic set at the age of seven—hopes the new lab will leave students more curious.
“The Mesozoic Era [about 252 to 66 million years ago] is the time when much of our modern ecosystems came into being,” he said. “Dinosaurs included the world’s first high browsers and the first large animal herds capable of transforming terrestrial systems. Mesozoic-furred pterosaurs and feathered birds were the first animals capable of global migration and, hence, global dispersal of seeds and microbes.”
Moreover, he noted, the angiosperms that make up 90 percent of the plants we have now also arose during that era, and with flowering plants came social insects, and the list goes on.
By learning how these systems came together, students can better understand how those same systems can also come apart in response to human activities.
“I want students to come away with a better appreciation of how interconnected our world is—and how vulnerable it is to change,” Kirkby said.
“We need to take better care of our world because everything we do within it has a ripple effect. That’s the takeaway message.”
Fun Fact: Did you know?
The University of Minnesota’s resin cast of an allosaurus fragilis skull may look like a Tyrannosaurus rex skull, but it’s only distantly related to Sue, the famous T. rex in the Chicago Field Museum. Their relationship, said Kirkby, is “much more distant than chimps are to humans.”
“Although both were large theropod dinosaurs,” Kirkby explained, “Sue would completely dwarf our Allosaurus. I have a cast of a T. rex tooth that you can compare to our friend’s and the difference is amazing.”
So, this begs the question, does the University of Minnesota own other T-Rex remains besides the tooth?
The answer: Yes—casts of a partial jaw and claws.
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