BY NOON ON A RAINY SUNDAY in March, the Sauriermuseum in Aathal, Switzerland, has seen a thousand visitors. Outside the one-time textile mill stands a colourful model of Spinosaurus, the bizarre, gigantic, amphibious predator first described in 1915. With a never-to-go-extinct movie franchise featuring the brute in its latest instalment, Jurassic World: Rebirth, it seems portentous — though the proprietor is merely happy to see his museum full. “Without days like this, we couldn’t fund the work of discovering and preparing new, scientifically significant fossils,” says Hans-Jakob Siber.

“Treasures nobody has seen before.” But Siber, a commercial collector, is no pirate of the past. His connection to deep time goes far beyond the thrill of the hunt to big-picture thinking on Earth history, from the planet’s accretion out of stardust 4.5 billion years ago to its eons of lifeless solitude, geologic upheaval and atmospheric makeover; from the appearance of life to subsequent evolutionary milestones and what each has meant.

Siber delivers me first to his current marquee, “T. rex Trinity,” a massive, shockingly toothy specimen before which children shriek and adults jaw-drop. Wow is clearly the same in any language. There’s a faint echo of my own first dinosaur encounters in the 1960s, when size and ferocity ruled, but the comparison ends there. In those days, bipedal skeletons were static and upright, tails to the ground, arms like a begging dog. Lit from below for effect, they loomed in dark rooms reverberating with eerie soundtracks like some carnival haunted house. Trinity, in contrast, is wholly animate, in horizontal full flight — and full light — like it’s just another day for one of the largest carnivores that ever lived. The deeper I head into Siber’s sanctum, the closer that world feels.

WITH SOMETHING approaching glee, Victoria Arbour, curator of paleontology at the Royal BC Museum, recounts using CT scanning to analyze tail-clubs in ankylosaurs, low-slung, tank-like herbivores covered in bony armour and spikes. When she was an MSc student at the University of Alberta, her husband had shown her an illustration of an ankylosaur “basically bopping a tyrannosaur in the face with its tail club. And I thought, ‘How do we know they could do that?’ So it became my thesis,” she recalls. “Back in 2007, we could only access hospital CT scanners — and they’d have to crank up the juice on them because fossils were so much denser than human bodies.” 

Arbour took a two-part approach: first, could ankylosaurs move their tail clubs fast enough to cause injury? Second, if they smashed something hard, might they also break their own tails? Using finite element analysis — a method for solving engineering problems like stresses and strains on a bridge — Arbour used the CT data to build a digital ankylosaur model; when force was exerted on a single point, the computer calculated how well this was distributed. Under most scenarios, the tail absorbed the forces without breaking. “I concluded tail clubs were adapted to function as weapons,” she says. “But against whom?”

In modern mammals, horns and antlers for fighting among one’s own species are only secondarily employed for defence, something Arbour often contemplated. Then she met Zuul, a particularly well-preserved ankylosaur with intact skin, spikes and even soft tissue. Noting several broken and healed spikes along Zuul’s flanks, exactly where you’d expect if two ankylosaurs lined up to do battle, Arbour argued in a 2022 paper that, rather than defence, ankylosaur tail clubs evolved primarily to fight for social dominance, elevating them to behaviourally complex animals like today’s large herbivores.

Arbour recently used another 3D modelling technique — photogrammetry — on ankylosaur footprints found in British Columbia. Requiring only a series of detailed, two-dimensional images easily acquired with a cellphone, “it’s a great way to share and study data,” she says. With photogrammetry, “you can have a 3D model of a track series hundreds of metres wide that could never fit in a museum.” Arbour created a digital version of a trackway found high on a rock wall that could then be analyzed and posted online for comparison with others.

Nevertheless, bones themselves can still answer many questions — especially with a large enough sample size. The Tyrrell’s Caleb Brown used this approach to elucidate face-biting behaviour in tyrannosaurs after seeing an upper jaw from Alberta’s Dinosaur Provincial Park that bore intriguing scars. The biting idea already existed in the literature, launching Brown on a search for healed tooth marks in other specimens: 202 tyrannosaurid skulls yielded 324 bite marks and battle scars. “If you found these kinds of things on only two or three specimens you could make up any story you wanted,” he says of the study published in 2021. “But when this many show the same thing, you can decipher some definite trends.”

Tellingly, the bite marks began to appear in half-grown tyrannosaurs. “The teenage years,” quips Brown about the developmental stage in which adult cosplay first takes hold. Across several species, orientation and positioning of scars showed the consistency expected from repeated conflict. And since face-biting analogues exist among modern turtles, lizards and fellow archosaurs like crocodiles, researchers interpreted the tyrannosaurid version as wrangling for territory or mates — an example of modern biology informing paleontology.

Because of such cross-pollination, we know more about Cretaceous dinosaurs like T. rex than we do about many living animals, says Steve Brusatte, author of The Rise and Fall of the Dinosaurs, adding “we’ve thrown the whole toolbox at [it].” Detailed CT scans show T. rex possessed not only brute strength, keen smell, hearing and vision but also high intelligence based on brain-to-body-size ratios. “We can say that Rex was roughly as smart as a chimp and more intelligent than dogs or cats,” writes Brusatte. “That’s a whole lot smarter than the dinosaurs of stereotype.” 

THIS T. REX WAS FEMALE — and pregnant. Mary Schweitzer had deduced this, incredibly, from the thigh bone of a well-preserved 68-million-year-old. Because the internal structure of bone in modern birds changes as calcium is diverted to build eggshells, the molecular paleontologist at North Carolina State University was curious about how pregnancy affected bone in this early egg-laying relative.

While using mild acid to leach out minerals formed during fossilization, however, she discovered something else: what looked like clear, still-flexible blood vessels. After abundant experimentation suggested this was fossilized soft tissue, Schweitzer published the improbable find in a pair of 2005 papers in Science. Two years later, she was able to demonstrate that proteins extracted from the bone indeed originated from dinosaur soft tissue and represented collagen — a large, rope-like molecule ubiquitous in any tissue requiring both strength and flexibility. But how had it been preserved for so long? Iron-rich blood once coursing through the leg of this T. rex. Freed from compounds like hemoglobin that it’s bound up in during life, forms iron free radicals that have a preservation effect on some organic molecules. “The free radicals cause proteins and cell membranes to tie in knots,” Schweitzer told Live Science when her find was published in 2013. “They basically act like formaldehyde.”

Meanwhile, another molecular epiphany was also underway. In 2008, Jakob Vinther, then a doctoral student at Yale, showed how “micro-balls” and “micro-sausages” observed under scanning electron microscopy in fossil bird feathers occurred only in dark-coloured areas. The balls and sausages were two types of melanosomes — tiny hollows inside hair and feathers containing the pigment melanin. And melanin, it turns out, is as tough as collagen when it comes to surviving fossilization. Charting the distribution of these structures in dinosaur skin and feathers brought their world into technicolour, swinging open a previously invisible door through which researchers quickly charged. Paddy Orr, then a member of Michael Benton’s lab at the University of Bristol, soon found the first objective evidence of dinosaur colour and pattern in Sinosauropteryx, a 125-million-year-old feathered theropod from China. The creature was ginger, with a ginger-and-white striped tail, like a roadrunner dressed as a lemur. 

Still another form of molecular insight — stable isotope analysis — has turbo charged the field of paleoecology. Isotopes are slightly different versions of the same chemical element, and varying ratios of these incorporated into bone and teeth during an organism’s life can reflect its ecology, diet and movements. Unlocking such chemical knowledge can help solve mysteries like the puzzle of Spinosaurus. With its skeleton coming together in dribs and drabs over the decades, the notion of whether it was an aquatic or terrestrial animal is hotly debated every time a new bone is found. But isotope analysis of its teeth definitively shows Spinosaurus living near water and eating fish — a life history tied to an aquatic ecosystem that appears unique among dinosaurs.