The world's 'heaviest animal in history' has been knocked off her throne
She's not that heavy, just big boned.

Perucetus Colossus
Last year, scientists in Peru announced they had discovered the world’s heaviest animal. Dubbed Perucetus Colossus or P. Colossus, for short, this ancient whale with a bloated body, small head and small fins, was estimated to tip the scales at a resounding 700,000 pounds. That’s larger than the largest animal up to that point—the Blue Whale—which can weigh up to 540,000 pounds.
The unusual fossils of P. Colossus believed to be nearly 40 million years old, were discovered in a desert in Peru. Whereas bones are normally spongy-looking, these fossils appeared dense and inflated, leading scientists to debate whether these were bones or rocks. It was determined they were, in fact, bones—vertebra bones, to be exact, each of which weighed at least 220 pounds. They also found ribs measuring nearly five feet across. All told, they found 13 vertebrae, four ribs, and part of a hip.
Using projections, it was estimated that this was the heaviest animal ever to have lived.
Headlines abounded, mentioning the size of this silly-looking beast.
Projected skeletal image of Perucetus Colossus
Ivan Iofrida/ WIKIMEDIA COMMONS
However, in late February 2024, scientists changed their tune. It turns out the estimates were off, and this chonky gal was merely big-boned, literally.
The new estimates put P. Colossus at 60 to 70 tons at 17 meters long and 98 to 114 tons at 20 meters long. It is still quite heavy, maxing out at 228,000 pounds, but not nearly as heavy as the blue whale, which maxes out at approximately 540,000 pounds or 270 tons.
P. Colossus as compared to a blue whale and a human
Cullen Townsend/Cullen Townsend (used with permission)
So what happened? Here’s some sciency language from the new study, “Downsizing a heavyweight: factors and methods that revise weight estimates of the giant fossil whale Perucetus Colossus."
“[The scientists who said P. Colossus was the heaviest animal] based their estimates on a new method, in which they first estimated the total skeletal mass of Perucetus through extrapolation from the skeletal material and then used the value to secondarily extrapolate its body mass, assuming skeletal to body mass ratios based on extant cetaceans and sirenians. A simple ratio mandates an isometric relationship between body and skeletal masses, and they justified this step by testing for isometry using a phylogenetically controlled regression.”
Ah yes, how many times a phylogenetically controlled regression has come around to bite us on the butt.
Translation: It’s understandable, sort of, why they used the wrong equation, but make no mistake—they used the wrong equation. And now, some science shade from the same paper:
“Their method involves questionable assumptions that suggest their body mass estimates are not reasonable…”
“It is important to note that the overall size estimate of Perucetus has remained the same,” Cullen Townsend told Upworthy. Townsend is an artist who renders prehistoric animals for the Natural History Museum Los Angeles, among others, and who created a corrected rendering to accompany the new paper.
Says Townsend: “What is now being debated is how heavy the animal potentially was. Our understanding of prehistoric animals is filled with holes and can change drastically with a new discovery or research. It is not surprising that scientists are coming to new conclusions. Our depictions of nearly every prehistoric animal have changed over time to better correspond with advancements in paleontology and our interpretation of the fossil record. Our current understanding of Perucetus is no different and will likely change again in the not-too-distant future. It is the nature of this field.”
So no "Real Scientists" reality show coming to cable TV anytime soon?
Or "Biggest Loser, Animal Style"? (P. Colossus wins, obviously)
The NatureWasMetal Reddit group saw this coming:
“Of course, Perucetus was going to be downsized… I’m never going to trust this sort of claim again, I felt like it couldn’t be true,” said Kaam00s.
“All my hopes and dreams shattered… I lived for that chonky whale man,” said Grouper3.
But Time-Accident3809 pointed out the silver lining:
“We are so lucky to coexist with the largest known animal to have ever lived. Now here’s hoping we don’t [mess] that up as well.”
There's a reason why some people can perfectly copy accents, and others can't
Turns out, there's a neurodivergent link.
A woman in black long sleeve shirt stands in front of mirror.
Have you ever had that friend who goes on vacation for four days to London and comes back with a full-on Queen's English posh accent? "Oooh I left my brolly in the loo," they say, and you respond, "But you're from Colorado!" Well, there are reasons they (and many of us) do that, and usually it's on a pretty subconscious level.
It's called "accent mirroring," and it's actually quite common with people who are neurodivergent, particularly those with ADHD (Attention Deficit Hyperactivity Disorder). According Neurolaunch, the self-described "Free Mental Health Library," "Accent mirroring, also known as accent adaptation or phonetic convergence, is the tendency to unconsciously adopt the accent or speech patterns of those around us. This linguistic chameleon effect is not unique to individuals with ADHD, but it appears to be more pronounced and frequent in this population."
Essentially, when people have conversations, we're constantly "scanning" for information—not just the words we're absorbing, but the inflection and tone. "When we hear an accent, our brains automatically analyze and categorize the phonetic features, prosody, and intonation patterns," writes Neurolaunch. For most, this does result in copying the accent of the person with whom we're speaking. But those with ADHD might be more sensitive to auditory cues. This, "coupled with a reduced ability to filter out or inhibit the impulse to mimic…could potentially explain the increased tendency for accent mirroring."
While the article explains further research is needed, they distinctly state that, "Accent mirroring in individuals with ADHD often manifests as an unconscious mimicry of accents in social situations. This can range from subtle shifts in pronunciation to more noticeable changes in intonation and speech rhythm. For example, a person with ADHD might find themselves unconsciously adopting a Southern drawl when conversing with someone from Texas, even if they’ve never lived in the South themselves."
People are having their say online. On the subreddit r/ADHDWomen, a thread began: "Taking on accents is an ADHD thing?" The OP shares, "My whole life, I've picked up accents. I, myself, never noticed, but everyone around me would be like, 'Why are you talking like that??' It could be after I watched a show or movie with an accent or after I've traveled somewhere with a different accent than my 'normal.'
They continue, "Apparently, I pick it up fast, but it fades out slowly. Today... I'm scrolling Instagram, I watch a reel from a comedian couple (Darcy and Jeremy. IYKYK) about how Darcy (ADHD) picks up accents everywhere they go. It's called ADHD Mirroring??? And it's another way of masking."
(The OP is referring to Darcy Michaels and his husband Jeremy Baer, who are both touring comedians based in Canada.)
Hundreds of people on the Reddit thread alone seem to relate. One comments, "Omfg I've done this my whole life; I'll even pick up on the pauses/spaces when I'm talking to someone who is ESL—but English is my first language lol."
Sometimes, it can be a real issue for those around the chameleon. "I accidentally mimicked a waitress's weird laugh one time. As soon as she was out of earshot, my family started to reprimand me, but I was already like 'oh my god I don’t know why I did that, I feel so bad.'"
Many commenters on TikTok were shocked to find out this can be a sign of ADHD. One jokes, "Omg, yes, at a store the cashier was talking to me and she was French. She's like 'Oh are you French too? No, I'm not lol. I'm very east coast Canada."
And some people just embrace it and make it work for them. "I mirror their words or phrase! I’m 30. I realized I start calling everyone sweetie cause my manager does & I work at coffee shop."