7 Important Things Science Has Learned About Dinosaurs Since "Jurassic Park"

The original movie came out 22 years ago this week, and a lot has changed since then. Spoiler: BIRDS ARE DINOSAURS.

1. Dinosaurs had feathers.

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Paleontologists had known that dinosaurs were way more colourful than the muted greens and browns of the Jurassic Park dinosaurs a couple of decades before the movie came out. But it wasn't until three years after its debut that we got confirmation that at least one species had feathers (there were, however, unconfirmed fuzzy specimens found earlier than this).

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Brian Switek writes in My Beloved Brontosaurus (Farrar, Straus and Giroux, 2013):

The first fluffy dinosaur discovery enthralled paleontologists. At the annual Society of Vertebrate Paleontology conference in 1996, scientists circulated a photograph of a small fossil that revealed a mane of fuzz along a dinosaur's back and tail.

It was a small theropod called Sinosauropteryx and had a coat of protofeathers that weren't enough for flight, only for show and keeping the dinosaur warm. This and further discoveries confirmed what's possibly the greatest fact you will ever know: birds are dinosaurs.

2. In fact, most dinosaurs probably had some kind of feathers.

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It wasn't until last year when scientists discovered a fossilised feather dinosaur that wasn't an ancestor of modern birds that they realised most dinosaurs could have been at least a bit fuzzy.

"Probably that means the common ancestor of all dinosaurs had feathers," study lead author Pascal Godefroit, of the Royal Belgian Institute of Natural Science in Brussels, told National Geographic News at the time.

Paleontologist Steve Brusatte, who wasn't involved in the research, agreed:

This does mean that we can now be very confident that feathers weren't just an invention of birds and their closest relatives, but evolved much deeper in dinosaur history. I think that the common ancestor of dinosaurs probably had feathers, and that all dinosaurs had some type of feather, just like all mammals have some type of hair.

3. Dinosaurs' feathers evolved before their ability to fly.

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An Archaeopteryx fossil revealed in a Nature paper in 2014 was covered head to toe in pennaceous feathers, the type birds use today to fly, but Archaeopteryx was flightless. The study's authors suggest that the feathers didn't evolve for any one reason, but were primarily used for display.

4. Raptors might not have hunted in packs.

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Actual velociraptors were turkey-sized creatures that probably wouldn't attack a human, unlike the Jurassic Park velociraptors, which most definitely did, and were actually based on a related but distinct dinosaur called Deinonychus.

Scientists believed for years that Deinonychus hunted in packs, co-operating and working together, just like the velociraptors in Jurassic Park. But in 2007 a paper published in the Bulletin of the Peabody Museum of Natural History pointed out that there was not enough evidence to say either way whether Deinonychus worked together. The scientists who published the paper, Roach and Brinkman, put forward another hypothesis: that the multiple Deinonychus fossils found at a hunt site were actually killed by each other as they fought over a carcass.

We do know that they at least spent some time walking together, but we don't know for sure why.

5. Brontosaurs might have existed after all.

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Brontosaurus was named in 1879, but in 1903 two scientists published a paper claiming the specimen was actually just a larger version of the Apatosaurus, and this conclusion stuck.

But this year, after applying some computer algorithms to a new data set in a process known as cladistics, a group of scientists argued that Brontosaurs should be a distinct genus after all. Time for a reprise?

6. Male and female stegosaurus might have looked different from each other.

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Male stegosaurus had wide plates from their head down to their tail, while females had taller ones, a paper published this year in the journal PLOS One claimed. It's the first evidence of "sexual dimorphism" – where the male and female of a particular species differ in appearance – in dinosaurs, though we see this kind of thing all around us in animals that are alive today (think of male peacocks and their huge feathery displays vs. the more demure female peahen).

Scientists have been looking for such evidence for years, but whenever it would look like they'd found it, the variations turned out to be due to something else – slightly different species, or different aged dinosaurs of the same species. In fact, some scientists have disputed the stegosaurus findings, claiming the evidence does not support that conclusion, and that the dinosaurs in the study could just have been different ages after all.

7. But there is one sure fire way to identify a female dinosaur: look for a special kind of bone.

"Indroda eggs" by Sballal - Own work. Licensed under CC BY-SA http://3.0 via Wikimedia Commons - commons.wikimedia.org

By Palauenc05 (Own work) [CC BY-SA http://3.0 (creativecommons.org], via Wikimedia Commons

Birds form a kind of bone tissue called medullary bone before laying their eggs. They draw calcium from this tissue and use it to form eggshell. And in 2005 paleontologist Mary Schweitzer revealed that a Tyrannosaurus rex had formed this bone tissue to lay their eggs too. A few years later, other paleontologists reported finding the tissue in two other dinosaurs too (Allosaurus and Tenontosaurus, for those who are keeping track).

So now you know.

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