What is this (possible) fossil from the triassic/jurassic boundary?

Digging Up the Past: What Fossils from the Triassic-Jurassic Boundary Tell Us

Ever wonder what it was like when dinosaurs were just getting their start? The Triassic-Jurassic boundary, around 201.4 million years ago, gives us a peek. It was a crazy time on Earth, marked by a huge extinction that totally changed the game for life on this planet. Think of it as a reset button, and fossils from this period are like clues to how life bounced back.

This wasn’t just any extinction; the Triassic-Jurassic extinction event (TJME) was a major league disaster, one of the biggest in Earth’s history. It’s like nature hit the “delete” button on a whole bunch of species, both in the oceans and on land. We’re talking about a serious wipeout – some estimate that nearly a third of marine life disappeared! Corals, shellfish, and even some plankton groups got hammered. And those conodonts, which scientists used like little time capsules? Gone. Poof. On land, big amphibians and reptiles bit the dust, which, in a twist of fate, opened the door for dinosaurs to really take over.

So, what caused all this mayhem? The prime suspect is a colossal volcanic eruption tied to the breakup of Pangaea, that supercontinent we all learned about in school. Imagine the Earth burping up massive amounts of lava as Pangaea split apart. All that volcanic activity released tons of greenhouse gases, like carbon dioxide, into the atmosphere. The result? Climate change went wild, and the oceans turned acidic. Some scientists even think a giant space rock might have crashed into Earth, adding to the chaos. Talk about a bad time to be alive!

Now, let’s get to the cool stuff: the fossils. What’s amazing is how the fossil record from this time shows a mix of survivors, groups that didn’t last long, and new creatures just starting to emerge. Reptiles, especially archosaurs (the ancestors of dinosaurs and crocodiles), ruled the land. Dinosaurs were around, sure, but they were still waiting for their big break.

In the oceans, ammonites – those swirly-shelled creatures – got hit hard, but some managed to hang on and evolve into new forms during the Jurassic. Bivalves, like clams, also took a beating, though some were tougher than others. And get this: new types of corals started building reefs, though they were pretty small at first.

On land, it was a real changing of the guard. Those big amphibians and crocodile-like phytosaurs? History. Therapsids, which were big players before the dinosaurs, faded away. But dinosaurs? They were just getting started, ready to fill those empty ecological niches.

Even plants tell a story. You don’t see as big a change in plant fossils as you do with animals, but there was still a shift. The landscape went from having lots of different types of plants to being dominated by conifers – think pine trees and their relatives.

The best part is that we’re still finding new stuff! Paleontologists are constantly digging up new fossils that give us a better picture of this period. Just recently, they found a new reptile in Brazil, Gondwanax paraisensis, that could change how we think about dinosaur evolution. And over in Switzerland, they unearthed a new sauropodomorph dinosaur from the Late Triassic, showing just how diverse dinosaurs were even back then.

All these discoveries help us understand how life responds to mass extinctions and how new forms of life evolve. It’s like putting together a giant puzzle, one fossil at a time, to reveal the story of life on Earth. And who knows what we’ll dig up next?