Science
Canny as a crocodile but dumber than a baboon — new research ponders T. rex's brain power
In December 2022, Vanderbilt University neuroscientist Suzana Herculano-Houzel published a paper that caused an uproar in the dinosaur world.
After analyzing previous research on fossilized dinosaur brain cavities and the neuron counts of birds and other related living animals, Herculano-Houzel extrapolated that the fearsome Tyrannosaurus rex may have had more than 3 billion neurons — more than a baboon.
As a result, she argued, the predators could have been smart enough to make and use tools and to form social cultures akin to those seen in present-day primates.
The original “Jurassic Park” film spooked audiences by imagining velociraptors smart enough to open doors. Herculano-Houzel’s paper described T. rex as essentially wily enough to sharpen their own shivs. The bold claims made headlines, and almost immediately attracted scrutiny and skepticism from paleontologists.
In a paper published Monday in “The Anatomical Record,” an international team of paleontologists, neuroscientists and behavioral scientists argue that Herculano-Houzel’s assumptions about brain cavity size and corresponding neuron counts were off-base.
True T. rex intelligence, the scientists say, was probably much closer to that of modern-day crocodiles than primates — a perfectly respectable amount of smarts for a therapod to have.
“What needs to be emphasized is that reptiles are certainly not as dim-witted as is commonly believed,” said Kai Caspar, a biologist at Heinrich Heine University Düsseldorf and co-author of the paper. “So whereas there is no reason to assume that T. rex had primate-like habits, it was certainly a behaviorally sophisticated animal.”
Brain tissue doesn’t fossilize, and so researchers examine the shape and size of the brain cavity in fossilized dinosaur skulls to deduce what their brains may have been like.
In their analysis, the authors took issue with Herculano-Houzel’s assumption that dinosaur brains filled their skull cavities in a proportion similar to bird brains. Herculano-Houzel’s analysis posited that T. rex brains occupied most of their brain cavity, analogous to that of the modern-day ostrich.
But dinosaur brain cases more closely resemble those of modern-day reptiles like crocodiles, Caspar said. For animals like crocodiles, brain matter occupies only 30% to 50% of the brain cavity. Though brain size isn’t a perfect predictor of neuron numbers, a much smaller organ would have far fewer than the 3 billion neurons Herculano-Houzel projected.
“T. rex does come out as the biggest-brained big dinosaur we studied, and the biggest one not closely related to modern birds, but we couldn’t find the 2 to 3 billion neurons she found, even under our most generous estimates,” said co-author Thomas R. Holtz, Jr., a vertebrate paleontologist at University of Maryland, College Park.
What’s more, the research team argued, neuron counts aren’t an ideal indicator of an animal’s intelligence.
Giraffes have roughly the same number of neurons that crows and baboons have, Holtz pointed out, but they don’t use tools or display complex social behavior in the way those species do.
“Obviously in broad strokes you need more neurons to create more thoughts and memories and to solve problems,” Holtz said, but the sheer number of neurons an animal has can’t tell us how the animal will use them.
“Neuronal counts really are comparable to the storage capacity and active memory on your laptop, but cognition and behavior is more like the operating system,” he said. “Not all animal brains are running the same software.”
Based on CT scan reconstructions, the T. rex brain was probably “ a long tube that has very little in terms of the cortical expansion that you see in a primate or a modern bird,” said paleontologist Luis Chiappe, director of the Dinosaur Institute at the Natural History Museum of Los Angeles County.
“The argument that a T. Rex would have been as intelligent as a primate — no. That makes no sense to me,” said Chiappe, who was not involved in the study.
Like many paleontologists, Chiappe and his colleagues at the Dinosaur Institute were skeptical of Herculano-Houzel’s original conclusions. The new paper is more consistent with previous understandings of dinosaur anatomy and intelligence, he said.
“I am delighted to see that my simple study using solid data published by paleontologists opened the way for new studies,” Herculano-Houzel said in an email. “Readers should analyze the evidence and draw their own conclusions. That’s what science is about!”
When thinking about the inner life of T. rex, the most important takeaway is that reptilian intelligence is in fact more sophisticated than our species often assumes, scientists said.
“These animals engage in play, are capable of being trained, and even show excitement when they see their owners,” Holtz said. “What we found doesn’t mean that T. rex was a mindless automaton; but neither was it going to organize a Triceratops rodeo or pass down stories of the duckbill that was THAT BIG but got away.”
Science
Video: NASA Announces Artemis III Crew
new video loaded: NASA Announces Artemis III Crew
transcript
transcript
NASA Announces Artemis III Crew
NASA announced the crew of Artemis III mission, which will fly to low-Earth orbit to test rendezvous and docking maneuvers with one or two lunar landers.
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“I am excited to welcome you as the next crew in the Artemis journey to successfully return to the moon — this time to stay.” “I’m honored by the role that I’ve been given. I’m also very humbled by the task in front of us. But first and foremost, I’m grateful.” “So with that, the Artemis II crew, comrade, hands you the baton. You got the controls.” “As you know, we had a significant anomaly at our Launch Complex 36A on May 28. We’ve redoubled our efforts and are moving forward.”
By Alisa Shodiyev Kaff
June 9, 2026
Science
Santa Monica Mountains’ last steelhead trout survived the Palisades fire — and even had babies
Scientists feared the Santa Monica Mountains’ last remaining steelhead trout were dead, smothered by debris flows unleashed by the Palisades fire.
But the endangered fish surprised them: A team of biologists recently spotted 30 of the rare trout — and 21 babies — in Topanga Creek.
“There was a lot of happy dancing in the creek,” said Rosi Dagit, principal conservation biologist for the Resource Conservation District of the Santa Monica Mountains, which works with public and private landowners to conserve natural resources.
That’s because the steelhead here are endangered, at both the state and federal levels. Once, they swam in most streams of the Santa Monicas, but their numbers plummeted amid overfishing and coastal development. Increasingly frequent wildfire has further stressed their habitat. Topanga Creek, a biodiversity hot spot, is home to their last known population in the mountains that stretch from the Hollywood Hills to Point Mugu in Ventura County.
The trout that were spotted, including this one, are part of a distinct Southern California population that’s listed as endangered at the state and federal levels.
(RCDSMM Stream Team)
The California Department of Fish and Wildlife spearheaded a complex mission to rescue trout threatened by the Palisades fire that sparked in January 2025.
Time was of the essence. The fire hadn’t yet been fully contained. But rain was on the way, which would sweep massive amounts of sediment from the denuded hillsides into the water. Fish are often killed this way.
Crews stunned the fish with electricity, scooped them up in buckets, trucked them to a hatchery and ultimately moved them to Arroyo Hondo Creek in Santa Barbara County.
Within days, Topanga Creek was choked with mud. Some assumed the fish left behind were goners.
But in March, the conservation district’s team found four. The following month, when water conditions were clearer, they saw more.
“These fish continue to amaze me,” said Kyle Evans, environmental program manager for the state Department of Fish and Wildlife, who had seen the damage to the creek. “I had seen populations get wiped out in similar situations. So when I heard, I was thrilled.”
Evans surmises the fish that survived were in an area of the creek where less charred material and sediment were swept in.
“These fish likely hunkered down, were hiding under some rocks or places to try to get away from the main concentration of flow,” he said. “And luckily they weren’t buried.”
The ones that were spotted were fairly small, around 6 to 14 inches. Rainbow trout and steelhead trout are the same species, but with different lifestyles. If the fish remain in freshwater, they’ll be considered rainbows. However, they can migrate to the ocean and become steelhead, where they typically grow larger before returning to their natal waters to spawn.
Topanga Creek hasn’t fully recovered from the damage it sustained, but scientists say it’s looking better. Surveys last year were “so depressing,” Dagit said, with very few animals, and stretches that were essentially transformed into flat roads from all the sediment buildup. Some of the riparian canopy burned right down to the creek.
Then came 32 inches of rain over the last nine months, scouring out and moving sediment, creating deeper pools. Dagit said they recently found newt egg masses for the first time in years, as well as a few adult newts and many frogs. Plants that provide cover are starting to recover.
She provided photos comparing certain pools last year and this year, some dramatically transformed. In September 2025, the Shrine Pool could have been an overgrown hiking trail. This April, it was filled with shallow water.
The Shrine Pool in September 2025, left, and the same location in April 2026, right, with RCDSMM’s Isaac Yelchin donning a wetsuit.
(RCDSMM Stream Team)
Topanga Creek is home to another endangered fish, the small but hardy northern tidewater goby, often described as cute. Not long before the trout operation, Dagit led a rescue of hundreds of these fish too. Many were repatriated to the lagoon at the mouth of the creek in a moving ceremony last June.
There’s still the matter of what to do with the trout that were moved to Santa Barbara County last year. Evans would like to bring them home to the Santa Monicas at some point, but isn’t sure if it will happen. On one hand, they could bolster the small, genetically isolated surviving population. On the other, they might inadvertently bring in a disease or bacteria. There is some time to decide. Evans estimates the creek still needs to recover for two to three more years.
For now, the fish are functioning fine in their adopted creek. Experts worried the trauma wrought by the move would disrupt their spawning process, but they had babies that spring. This year, they spawned again.
Science
Pacifica pier cracks, another coastal casualty as seas continue to rise
The Pacifica Municipal Pier was shut down and taped off Thursday after city workers noticed cracks running through the landmark structure and concrete chunks falling into the ocean.
It’s just one of many coastal California structures that have recently crumbled under pressure from a rising and relentless ocean.
Officials from the small, beach city south of San Francisco said the pier was closed due to “cracking, separation, and displacement of the concrete walkway and structural elements.”
It will stay closed while structural engineers asses its safety.
Photos taken by city employees show a wide crack that runs from top to bottom and across the structure as well. Other photos show a large horizontal crack under the foundation of a small restaurant on the pier, the Chit Chat Cafe.
The cafe was also shut down.
This is not the first time the 53-year-old pier has shown signs of stress. In 2021, part of it was shut down after handrails along the edge collapsed. And in 2023, after a series of storms pummeled the Central California coast, damaging parts of the pier, the structure was partially closed for more than year.
Those same storms caused extensive damage in Aptos and Capitola, 70 miles south, where piers and waterfront infrastructure were swept away or damaged.
In 2024, a 150- to 180- foot section of the Santa Cruz wharf was ripped off by powerful waves.
At least 10 of the state’s dozens of coastal public piers were closed for part or all of 2024 due to structural damage sustained in winter storms since 2022. At least five others have longer-term upgrades planned to address structural issues.
“These things are costly to maintain,” said Zach Plopper, senior environmental director at Surfrider. “They are a part of our California coastal culture in many ways, but we’re going to need to reckon with, one, the state that they’re in, and two, the continuous and worsening threats they’re going to experience,”
He said most of the piers were constructed in the early 1900s, and they weren’t built to withstand decades of rough seas, storms and rising sea level.
“With this incoming El Niño, which is forecasted to be significant, and this marine heat wave we’re in the midst of, we’re kind of in uncharted waters as far as what this winter could bring in terms of storms and swells to the California coast, and we’re likely going to see a lot more damage,” he said. “Not just piers, but roads and other coastal infrastructure up and down the state.”
There was no storm in Pacifica earlier this week, so no single event could be blamed for the destruction.
However, a 2025 report from an outside engineering firm, GHD, found that several sections of the pier were in “poor” or “serious” condition, and they recommended closure before anticipated storms or events that could “subject the piles to high winds, swells and large waves.”
The firm found several areas of the pier where concrete was missing and rebar was exposed and corroding.
“The pier has continued to experience high winds and large waves in a harsh marine environment,” the engineers wrote in the report, noting that continuous exposure to seawater or marine spray was “detrimental” to the structure.
A 2023 city report estimated it would cost $19 million to repair.
That same year, a state law was enacted to require local governments along the California coast to plan for sea level rise in the coming decades.
Sea level has risen some 8 inches, on average, along the coast in the past 150 years, Plopper said, and researchers anticipate another foot in the next 25 years.
“We’re going to see profound shifts on our coastline, none that we have ever experienced before, and building static structures on the coast just doesn’t work all that well,” he said. “We’re going to have to make some really hard decisions.”
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