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“Tiny Tyrannosaur Hints at How T. Rex Became King,” by Nicholas St. Fleur

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Tyrannosaurs weren’t always tyrants. For millions of years, the ancestors of the regal T. rex were relegated to second-class predator status while a different dinosaur dynasty ruled over what is now North America: towering allosaurs.

Nicholas St. Fleur: I love having fun with my leads. Tyrannosaurs are known as “tyrant lizards,” so I thought it would be whimsical to flip that on its head in the opening to this story.

T. rex is the king of the dinosaurs. So I wanted to continue with this Mesozoic monarchy theme I had going. I try to be clever with my wordplay, so I used “regal” and “relegated” because they play well with the “rex” in T. rex. I took that idea further by saying the tyrannosaurs were once “second-class predators” as a sort of nod to the term “second-class citizen,” which you might find under a monarchy. Then we deliver the reason tyrannosaurs weren’t always the big baddies: there were even more ferocious dinosaurs roaming around.

I’ll admit that my opening paragraphs are usually my most colorful because I typically spend the most amount of time on them. You really have to grab a reader’s attention with your first few sentences if you want to have them read the entire story. It’s for that reason that my first few paragraphs are often the last part that I write. I’m constantly tinkering with the wordplay.

But the allosaurs went extinct during the late Cretaceous, allowing tyrannosaurs to seize the throne and then evolve into large killing machines like T. rex and Tarbosaurus.

“Seize the throne”: another monarchy reference.

To better understand how and when tyrannosaurs became giants, paleontologists have sought examples of their lineage from when they were small. Their latest discovery is a tiny tyrannosaur that lived in the shadow of larger predators some 96 million years ago.

Called “Moros intrepidus,” the new species is the oldest Cretaceous-period tyrannosaur ever found in North America and among the smallest in the world, measuring only about as big as a deer. Because scientists have previously found large tyrannosaurs in North America that date to 81 million years ago, the newly discovered species helps narrow the window of when tyrannosaurs became huge.

In journalism, we call this portion the “nut” because it tells readers why the information the article imparts is important. You can find a “nut” paragraph or two in nearly every news article you read. This nut is helping readers understand the point of this finding, which is in that last sentence — it lets scientists “narrow down the window when tyrannosaurs became huge.”

Another thing to notice: I made the “big as a deer” comparison because when we write about sizes, we try to make real-world comparisons that will give our readers a better idea of the scale we’re talking about.

“We now know it took less than 15 million years for them to go from these subsidiary secondary players in the environment to top of the food chain,” said Lindsay Zanno, a paleontologist at North Carolina State University. She and her colleagues published their discovery Thursday in the journal Communications Biology.

I try to always place a quote from one of the main scientists involved high up in my story. The more fun and eye-catching the quote, the higher up it typically tends to appear.

Also, we always mention the day and the journal where the new paper was published, and provide links so readers can see the information for themselves. Unfortunately, these papers are often behind paywalls.

In 2012 while Dr. Zanno was fossil hunting in central Utah, she noticed a dinosaur leg bone sticking out from a rocky hillside. The next year she and her team excavated the fossilized remains. Although the bones were poorly preserved, she could tell by how thin they were that they belonged to a theropod, which is the major group of carnivorous dinosaurs that include allosaurs and tyrannosaurs.

I’m a big fan of retelling the moments of discovery. Depending on the word count that I’m allotted, I try to make this part of my story as descriptive as possible. My goal is to pick up the reader and place them right there, as if they were at the field site with the researcher.

Looking back at this part of the story, I would have liked to have been more descriptive of what it was that Dr. Zanno saw. I often get some of my best quotes when I ask a scientist, “What was going through your head at that exact moment when you found that dinosaur bone?”

To me, a story really sings when it shows the scientists’ emotions. In this particular case, I could have done a better job of capturing that moment.

Her colleague Aaron Giterman at the North Carolina Museum of Natural Sciences painstakingly pieced the leg together over the course of a year. After examining the dinosaur’s tiny foot and upper leg, Dr. Zanno determined it belonged to a tyrannosaur. From hip to toe it measured about four feet long and the dinosaur was estimated to weigh about 170 pounds. T. rex, for comparison, strutted around on legs that were about 12 feet long, and weighed more than 10,000 pounds.

Science takes time. Often a lot of time. It can be brutal, tedious work. I try my best not to romanticize it, but rather to describe it as a process that often involves a lot of people working together. And oftentimes their jobs may not be the most exciting.

In this case, Aaron Giterman wasn’t a scientist mentioned on the paper. Dr. Zanno had mentioned to me that they worked with a technician who pieced the leg back together, and I thought it would be important to the story to highlight his work alongside that of the paper’s authors.

Science is very collaborative but not everyone gets to be an author on the paper, so I often ask for the names of people who were involved but not mentioned. Typically this includes citizen scientists or grade school students who stumble upon fossils while walking around the beach or digging in a park. I think stories like these show the readers that people just like them are contributing to science and that they could, too.

Meanwhile, at the end of these paragraphs you’ll see the nitty-gritty numbers that give the reader an idea of how big this dinosaur was. By comparing it to T. rex we see that it was actually pretty minuscule. A “tiny rex” if you will!

The next steps were to find whether the tiny tyrannosaur belonged to a new species or was a juvenile of a known species.

Aurore Canoville, a postdoctoral researcher in Dr. Zanno’s lab, collected small samples from the bones. Using a microscope, she identified growth marks in the bone tissue that provided clues to the dinosaur’s age, like tree rings. Dr. Canoville saw evidence suggesting the tyrannosaur was at least 6 or 7 years old. The growth marks, she said, were also spaced closer and closer together, indicating the tyrannosaur was nearing full maturity when it died.

I also try my best to interview researchers beyond just the first author and the senior scientists. It provides you with a bigger look into what the story really is. Sometimes these conversations give you little anecdotes that you would never get out of the main researchers.

I once spoke with a student who told me that because his work with fossilized butterflies was so delicate, he needed to use the finest brush possible. That meant using a brush tipped with a human nose hair! That became the headline to our story: Finding the Oldest Fossils of Butterflies Using a Human Nose Hair.

I had a longer description of what Dr. Canoville did, but my editor rightfully condensed it to the previous sentence. Sometimes we writers get so excited about the methods that scientists use that we forget that we’re probably going to lose the reader if we talk about things like grounding down epoxy resins. This is why a good editor is so important!

Finally, the comparison to tree rings helps the reader better understand why the scientist had to study the growth marks on the bone.

“When we found out it was actually almost an adult, we could tell that it was a new species of a very small tyrannosaur,” said Dr. Canoville. Their findings also suggested that the dinosaur was most likely an agile hunter.

Here, the researcher says what the ultimate goal of measuring the growth marks was: determining that the tyrannosaur was an adult and a new species. That’s what helped them to make their overall finding.

Thomas Carr, a paleontologist from Carthage College in Wisconsin who was not involved in the study, said the finding “lifts the lid on what the earliest tyrannosaurs in North America really looked like.”

Stephen Brusatte, a paleontologist at the University of Edinburgh in Scotland who was also not involved in the paper, said the discovery pushed the tyrannosaur mystery forward in time.

When we report on new research we always try to reach out to experts to provide context for our readers. That way we aren’t overhyping or underselling a new finding.

Sometimes the outside experts disagree with a finding, at which point we take their concerns to the paper’s authors and ask them for their responses to the criticism. That wasn’t the case for this paper.

I’ve interviewed both Thomas Carr and Stephen Brusatte in the past and I knew they’d be excellent sources to weigh in on this new finding.

Typically, I try to reach out to outside sources early in my reporting process. Often when I sit down to write I distill my interviews with them into a few short paragraphs that capture their overall thoughts on the paper. Even though they usually appear at the bottom of my story, these paragraphs are usually the first ones that I write. It helps me to get “something on the paper” because for many of us writers there is no bigger hurdle to overcome than looking at a blank word document.

“When did these second-tier hunters become the bus-sized bone-crunchers that terrorize our imaginations?” said Dr. Brusatte. “It must have happened sometime between about 90 and 80 million years ago, and we’re going to need new fossils from this time to figure it out.”

Dr. Brusatte in particular is a terrific science communicator who always delivers elegant, yet adrenaline-inducing quotes. You see his name pop up a lot in popular dinosaur articles. And his quote here was just what I needed to end my story.

If you’d like to hear more from Mr. St. Fleur, and from fellow science writer James Gorman, you might be interested in our on-demand webinar, Teaching With The Science Times.