Who was boss before the dinosaurs?
Who was boss before the dinosaurs? Large hippo-like mammal forerunner ("Placerias") that lived, and died off, during the Triassic. (National Park Service Image)
Who was boss before the dinosaurs?
Lexile: 860L

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The Jurassic witnessed a world populated by dinosaurs. While giant plant-eaters munched their way through ferns and conifer forests, large carnivores chased them down for lunch.
At the height of the Age of Dinosaurs, they were found on every continent. They thrived in the warm environments of the time.
But, dinosaurs were not always so prominent. Fossil evidence shows that they arose about 230 million years ago during the Triassic period. But they remained scarce as other reptiles took center stage. Many mammal forerunners, such as the large plant-eater Placerias, prospered. Huge crocodile-like animals like Smilosuchus were the top predators of the Triassic.
Paleontologists who study the fossil record have discovered that something big happened 200 million years ago. It radically changed life on land and in the sea. And it paved the way for dinosaur diversification and prominence.
What happened was so important that it caused more than half of all life on Earth to go extinct. The large crocodile-like reptiles that had dominated the landscape were eliminated. So were many of the mammal forerunners.
Find out more about the events that opened the door for the Age of Dinosaurs. Join us on Thursday, October 8, 2015, for a "Smithsonian Science How" live webcast on How Fossils Explain the Rise of Dinosaurs. It is airing at 11 a.m. and 2 p.m. EDT on the Q?rius website. Paleontologist Dr. Hans Sues from the National Museum of Natural History will appear live to discuss and answer questions. Get teaching resources to support your webcast experience.

Source URL: https://www.tweentribune.com/article/tween56/who-was-boss-dinosaurs/

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To study dinosaurs, why do scientists rely on fossils instead of photographs?
Write your answers in the comments section below

  • judea-buh
    9/29/2015 - 10:00 a.m.

    That's so cool how the dinosaurs where not the only interesting creatures in that time zone. I like dinosaurs but I also like other animals that are like the dinosaur but stronger.

  • tylerb-1-coo
    9/29/2015 - 10:35 a.m.

    To get better exams on fossils than pictures because picture are weak and not accurate as a real fossil.

  • christianr-4-bar
    9/29/2015 - 11:51 a.m.

    Scientists rely on fossil instead of photographs because the fossils can help them build the dinosaurs and see how it made instead of seeing a picture so they can test how is walked and what was its shape.

  • andrest-wil
    9/29/2015 - 01:00 p.m.

    Scientists rely on fossils because there were no cameras back then and no people to take photos.

  • shanelr-wil
    9/29/2015 - 01:05 p.m.

    They use fossils because photographs was not invented the time dinosaurs lives. So they have to rely on fossils other than photographs.

  • levenicel-Orv
    9/29/2015 - 01:13 p.m.

    So the boss of the dinosaur was a croc so basically still live today and there not extinct just think of it it said it was a large croc and there are large crocs still liveing today so there aren't extinct imagin if all the extinct animalls came back that would be crazy and if the boss of the dinosaurs was a croc doesent that mean there the bosss now just think about it.

  • masonl1-jen
    9/29/2015 - 02:28 p.m.

    because they did not have cameras back then.

  • ethann-1-gra
    9/29/2015 - 02:41 p.m.

    placerias are the coolest things ever in my opinion

  • antoniak-jen
    9/29/2015 - 02:42 p.m.

    Because there was no cameras.

  • ariahr-jen
    9/29/2015 - 02:45 p.m.

    Because you can learn more and their was no cameras and no people.

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