CLOSE
Original image

10 Bone-Headed Facts About Pachycephalosaurus

Original image

Pachycephalosaurus’ domed, heavily-built head looks like it was capable inflicting some serious damage. Unfortunately, trying to decipher how this animal used that noggin has given many poor scientists headaches of their own.

1. Its Skull Roof was Up to 10 Inches Thick.

Pachycephalosaurus heads only reached total lengths of two feet or so. In case you’re curious, human men and women have an average skull thickness of 6.5 and 7.1 millimeters, respectively.

2. Pachycephalosaurus Heads Were Once Mistaken for Dinosaur Kneecaps.

Dinosaurs—unlike mammals—lacked kneecaps altogether. However, during the late 19th century, this fact wasn’t widely known, and few non-skull-related Pachycephalosaurus bones had been found, so this weird hypothesis is pretty forgivable.

3. One of its Close Cousins Has the World’s Longest Dinosaur Name.

Try saying this five times fast: Micropachycephalosaurus. It means “small, thick-headed lizard.” What a flattering label!

4. Pachycephalosaurus May Have Drastically Changed Shape with Age.

Dr. John R. “Jack” Horner—who, among other accomplishments, served as the Jurassic Park trilogy’s dino consultant—maintains that Pachycephalosaurus and two similar creatures which shared its habitat were really the same animal. Stygimoloch and Dracorex are smaller and had much flatter skulls. If Horner’s correct, these represent two juvenile stages of Pachycephalosaurus. He expands upon his argument at the 8:30-mark of this TED clip: 

5. It Belongs to the Same Dinosaur Clade as Triceratops.

Triceratops and its horned/frilled kin are collectively known as “ceratopsians.” Together with the pachycephalosaurids, they form a diverse dinosaurian group called the marginocephalia (“ridged heads”).

6. Perhaps Pachycephalosaurus Butted Heads.

Paleo-artists have traditionally drawn Pachycephalosaurus ramming headlong into each other musk ox-style. Does the available evidence support this?  Some scientists think so, claiming that their domes were well-equipped for absorbing such brutal impacts. Others, meanwhile, have their doubts.

7. … Or, Alternatively, Pachycephalosaurus Might’ve Preferred Flanking.

Today’s giraffes violently slam their heads into rivals’ sides. Maybe Pachycephalosaurus behaved likewise. Many of its kin had conspicuously-wide ribcages, which could theoretically withstand this sort of abuse. Also, try making two bowling balls forcefully collide at point-blank range. You’ll notice that the spheres will only briefly connect before quickly sliding apart thanks to their curvature. Pachycephalosaurus domes were also quite rounded and potentially faced the same mechanical challenge. If so, “flanking” might’ve been a more effective undertaking when tempers flared.

8. Pachycephalosaurus Had to Worry About T. rex.

Tyrannosaurus and Pachycephalosaurus both dwelled in western North America during the late Cretaceous period around 65 million years ago. That thick head was therefore possibly employed as an anti-predator weapon. 

9. Regardless, Pachycephalosaurus Could Sustain some Serious Cranial Trauma.

In 2012, paleontologist Joseph Peterson subjected a Pachycephalosaurus skull to CT scanning and found numerous potential injury marks “clustered over the thickest region of the dome,” which—in his view—seemingly corresponded with the head-butting hypothesis.

10. Pachycephalosaurus is (Indirectly) Linked to the Harry Potter Series.

To honor its dragon-like appearance and a certain best-selling book series, one new pachycephalosaurid species was named Dracorex hogwartsia in 2006. Upon hearing the good news, J.K. Rowling proclaimed “[this] is easily the most unexpected honor to have come my way since the publishing of the Harry Potter books! I am absolutely thrilled to think that Hogwarts has made a small claw mark on the fascinating world of dinosaurs.” She also added that “I can’t help but visualizing [Dracorex] as a slightly less pyromaniac Hungarian Horntail.”

But don’t get too excited, Potter fans. Remember: Dracorex could simply be nothing more than a young Pachycephalosaurus, which would make the Hogwarts-themed moniker obsolete. 

Original image
Denver Museum of Nature & Science
arrow
science
Construction Workers in Colorado Discover 66-Million-Year-Old Triceratops Skeleton
Original image
Denver Museum of Nature & Science

Construction projects have yielded some pretty amazing ancient finds: ancient ports, Stone Age homes, forgotten cemeteries, burial grounds, and even the bones of King Richard III. Now, The Denver Post reports that workers in Thornton, Colorado, just north of Denver, recently discovered a 66-million-year-old adult triceratops skull, along with other bones, while breaking ground for the city's new public safety facility. It's an incredibly rare find as most of the fossils found in the region are about 12,000 years old.

Instead of digging on—which may have destroyed the skeleton—the workers contacted experts to take a closer look. Joe Sertich, curator of dinosaurs at the Denver Museum of Nature and Science, was called to the scene to examine the bones.

"This is what we as curators dream about—getting a call about a possible fossil and confirming it's not just a dinosaur fossil, but a record-breaking one!" Sertich said in a statement.

Museum staff, construction staff, and museum volunteers work to excavate the Thornton triceratops skeleton on August 30, 2017.
Museum staff, construction staff, and museum volunteers work to excavate the skeleton on August 30, 2017.
Denver Museum of Nature & Science

So far, scientists and volunteer diggers have unearthed the skull, two horns, a portion of the dinosaur's frill, shoulder bones, the beak at the front of the lower jaw, and ribs and vertebrae. The skeleton appears to be separated, indicating that the dinosaur may have died and lain on the ground for anywhere from a few days to a few weeks, according to The Washington Post. As it decayed, its bones and flesh fell apart, and other dinosaurs, like T. rex, may have even taken a nibble at the corpse.

Joe Sertich, curator of dinosaurs at the Denver Museum of Nature & Science, speaks with a construction worker while leading the excavation in Thornton, Colorado of a newly discovered triceratops skeleton.
Joe Sertich, curator of dinosaurs at the Denver Museum of Nature & Science, speaks with a construction worker while leading the excavation in Thornton, Colorado of a newly discovered triceratops skeleton.
Denver Museum of Nature & Science

Experts say the triceratops skeleton could be the most complete Cretaceous dinosaur ever discovered in the Front Range region, and one of the oldest fossils. They've also noted that the newly discovered dino fits a larger pattern: When found in the Denver area, triceratops are typically half the size of similar ones that once lived in the Dakotas and Montana.

A closeup of the triceratops fossil as it's unearthed in Thornton, Colorado.
A closeup of the triceratops fossil as it's unearthed.
Denver Museum of Nature & Science

"We don't really know why," Sertich said in a Facebook Live broadcast. "Even though we have hundreds of triceratops from the American West, we only have three good skulls. And this might be one of the best skeletons to tell us why Denver triceratops are smaller than all of their cousins everywhere else."

[h/t The Denver Post]

Original image
© Zachary James Johnston, The Field Museum
arrow
science
SUE the T. Rex Is Getting a Makeover
Original image
© Zachary James Johnston, The Field Museum

Our lives are constantly changing—even those of us who are already dead. The beloved fossilized T. rex skeleton known as SUE will soon be treated to a makeover and new digs at The Field Museum in Chicago.

SUE’s move is motivated by more than just luxury; the museum needs to clear out its great hall to make room for the largest dinosaur ever discovered. A private donor has bestowed the museum with a full-size cast of the Argentinean titanosaur Patagotitan mayorum.

Illustration of a titanosaur cast in a great hall.
The Field Museum

The touchable 122-foot-long marvel will stretch across Stanley Field Hall and upward into the second story. SUE will be disassembled in 2018 and eventually relocated to a fancy new suite in another hall along with other fossil specimens.

Illustration comparing the size of a titanosaur, a human, and a T. rex.
The Field Museum

“At 40.5 feet long, she’s the world’s biggest T. rex, but in that giant hall, people sometimes remark that she’s smaller than they expected,” senior exhibitions project manager Hilary Hansen said in a statement.

“By putting her in her own gallery in our Evolving Planet exhibition, she’ll be put into the proper context of her fellow dinosaurs, and she’ll dominate the room.”

(SUE’s sex is unknown, but many museum staffers take a cue from the fossil’s ladylike name and use female pronouns.)

With the new setup comes a whole new look. The SUE we see today is incomplete; when the skeleton was assembled in 2000, dinosaur curators omitted one group of bones, unsure where to put them. They’ve since figured it out. The bones are gastralia, which cage the stomach area like a lower set of ribs.

Dinosaur gastralia arrayed  in a bed of sand.
© Zachary James Johnston, The Field Museum

T. rex had a bulging belly,” associate curator of dinosaurs Pete Makovicky said in the statement. “It wasn’t sleek and gazelle-like the way you might think.”

Over the last two decades since SUE’s assembly we’ve learned a lot about the way SUE and family looked and moved. Makovicky and his colleagues also plan to tinker with SUE’s posture so that upon the grand re-debut in 2019, “she’ll be walking rather than skulking.”

Or strutting, more accurately. The gloating dinosaur’s Twitter bio now reads “Private Suite Haver.”

Never one to be left out of the conversation, SUE issued a public comment, writing, “For years now, I've been pitching this to the Museum. A room with a better defensible position against velociraptor attacks and reduced exposure to possible meteorite collisions. Finally, the mammals in charge have come to their senses."

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios