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While medical discoveries & vaccine advances took the spotlight during Covid, other large scientific discoveries were still occurring! From dinosaurs to parasites, join Michael Aranda for a new episode of SciShow that's all about scientific discoveries!

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[SciShow Intro].

Michael Aranda: It's probably fair to say that just about everyone's brains this year have been dominated by this pandemic. But other science stories did happen in 2020, including amazing discoveries about everything from dinosaurs to parasites. We didn't get a chance to cover all of them, but now, they're getting their chance to shine. So here are three unbelievably cool stories you might have missed.

 Swimming Spinosaurus

First, back in April, researchers settled a major argument about dinosaurs. For a while, scientists had figured that pretty much all species of non-avian dinosaur were terrestrial. They could venture out into water every now and again but they mainly stuck to dry land. The major exception to this, however, was Spinosaurus aegyptiacus, often known as Spinosaurus for short.

Based on features like its long, narrow jaws and croc-like teeth, we thought it was at least semi-aquatic, maybe hunting along the rivers in northern Afric,a although that idea was definitely met with some push-back. Now though, there seems to be strong evidence that it wasn't just prowling around rivers, it may have been a proper aquatic beast. The key evidence was published on April 29th, and it comes from tailbones discovered in Morocco in 2018.

We don't have a ton of fossils of Spinosaurus because they were accidentally destroyed in World War II, so this was a major find. Researchers used the fossils to make a digital reconstruction of the whole animal, and they found that its tail would have looked a bit like a newt or crocodile's tail: long, flat, upright, and strong. What's more, scientists also made and tested a robotic model of this tail, and found it could probably produce enough force to let the animal swim.

If this is confirmed, it would end a year's long argument and really expand our picture of where dinosaurs lived and what they were capable of.

 How Old Are Whale Sharks?

Next is a story about other swimming giants also from April, and it involves a clever solution to a tricky puzzle. In the spring, scientists figured out that we can use nuclear residue from Cold War tests to figure out how old whale sharks are. Whale sharks are the largest living species of shark, and we want to understand and protect them. That's easier said than done.

Like, one thing we'd love to know is their life history, things like how long they live and how fast they grow. But there was a conundrum. Researchers couldn't agree how to measure their age.

There are growth bands on their vertebrae like tree rings but studies were conflicted about if one ring equals one year or just six months. Well, it turns out the secret to figuring it out was nuclear weapons tests back in the 1950s and 60s. Scientists realized those tests would have increased global atmospheric levels of a rare form, or isotope, of carbon, called carbon-14.

And it would have been picked up and incorporated into the sharks' bones. So the scientists got vertebrae from two of the oldest deceased specimens available, and compared the isotope levels in their vertebra's bands to ocean water samples from years ago. By looking at the bands and the amount of carbon-14 in each, they were able to figure out what year different bands were put down.

And with those landmarks in place, they finally put the original question to rest, and concluded that each band equals one year. Using this new knowledge, the scientists were also able to conclude that whale sharks grow more slowly and live longer than we generally assumed, something that could help us better understand these ocean giants and how their populations are doing.

 Punctual Parasites

Finally in May, news broke about one of our most notorious diseases, one that's been plaguing us long before COVID-19: malaria. One of the signature signs of malaria is regular, recurring fevers. These happen because the malaria parasites enter and breed inside red blood cells, then burst out in a synchronized wave of new parasites and waste materials. For the parasites, it's possibly a way to evade the immune system.

But for humans, all those waste materials trigger a fever. But what's interesting is that depending on the exact species of parasite, these waves can happen like clockwork. Like some species that infect humans trigger fevers every two days.

Others, every three. For a long time we've thought that the parasites may be using the host's circadian rhythm to time things, basically our daily internal clock. But in May, we got published evidence that the parasites use their own biological clock instead.

To figure this out, scientists bred mice to have different circadian rhythms, some normal, some longer, and some nonexistent. Then they infected the mice with the parasites and they found the parasite cycle would kind of adjust to match their host, but not perfectly. Also, the parasite cycle existed even in mice without consistent circadian clocks.

This all suggests that the parasites have their own clock, though it's kept in sync by cues from the host's body. That helps the individual parasite sync up with each other. The scientists even identified genes that might be behind this.

Now, there isn't a huge conclusion about how to treat malaria here, at least not yet, but it's completely possible that this hidden interaction is something we could tweak and exploit to our benefit to put another deadly disease to rest.


So 2020 has been quite a year, but in the science world, there's a lot to celebrate. Some scientists have been tackling this pandemic, including studying the virus and potential treatments and vaccines. Meanwhile, researchers like these have been pouring time and energy into conservation, natural history, and other diseases. And in both cases, our understanding of the world is that much better for it.

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