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Hey, Brain Stuff, Lauren Vogelbaum here.

Many of us first learned about the Dilophisaurus through the Jurassic Park franchise.

It certainly made them memorable.

In the novel by Michael Crichton from 1990, these dinosaurs spit a sort of gooey poison in the face of prey to disable them,

and the 1993 film added bright red and yellow ruffs or frills that pop up from the creature's neck to surround its head.

The overall effect is scary and beautiful, and unfortunately, or perhaps fortunately,

completely made up as far as we know. Dilophosaurus was, however, one of the few dinosaurs

in Jurassic Park that lived in the actual Jurassic period.

All of the non-avian dinosaurs were confined to the geologic era called the Mesozoic.

We divide the Mesozoic into three periods, the Triassic, the Jurassic, and the Cretaceous,

based on major changes that informed the

landscape and climate and life on Earth. The Mesozoic era went out with a bang. A mass extinction

marked the end of the Cretaceous period 66 million years ago. Birds were the only dinosaurs

that survived the catastrophe.

Their brethren had a good run, though.

The earliest dinosaurs evolved around 243 to 231 million years ago during the Triassic period.

A time of great reptilian diversity, the Triassic gave way to the Jurassic about 199 million years before the present. Prior to that transition, most carnivorous dinosaurs were small-bodied.

Dilophosaurus was a sign of bigger things to come. The beast roamed what's now southwestern North

America in the early Jurassic period, about

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