SearchResearch Challenge (8/23/23): What's that in the belly of the Redondasaurus?

I looked at the Phytosaur in real shock...

Because there, in the dinosaur hall of the Carnegie Museum of Natural History in central Pittsburgh, was what looked to be a massive crocodile.

This is Redondasaurus bermani. It was huge and utterly evil looking, clearly a watery death machine that was 6.4 m (21 feet) long, and lived in the rivers and swamps of Triassic North America some 252-201 million years ago.

Impressive.

I've seen lots of assembled skeletons before. It was big and carnivorous, but as I stood in front of the skeleton, I noticed something that I don't think I'd seen before.

See that collection of what look like ribs in its belly?

Here's a close-up shot:

See what I mean? There is the backbone above, with a lot of ribs hanging off the vertebrae. You can easily see the massive leg bones and feet.

But there, hanging below the backbone and ribs is something else--a kind of basket of upward pointing ribs that seems attached to the sternum.

I don't know that I've seen that on any other animal. Or have I just not been paying attention?

Naturally, this led me on a merry SRS quest, which condensed into these two Challenges for you:

1. What do you call that thing in the chest and belly of the Redondosaurus bermani?
2. Do other animals have this thing now, or was it just an Age of the Dinosaurs skeletal feature?

I've found the answer now after a bit of quick searching on my phone while standing in front of the beast. I have to say, I was pretty surprised by the answer to Challenge 2.

Another surprise was learning that the Redondosaurus is actually NOT related to any living crocodiles or alligators? It was, as they say, a "Late Triassic clade of crocodylian-like predators." That is, there were other kinds of Redondosaurus (collectively called the Phytosaurs) that filled the ecological niche that crocs and alligators fill in todays swamps. They had short legs, wide, heavy bodies with rows of armored scales, long tails, and long toothy snouts. The only obvious difference between crocodiles and phytosaurs is that crocodiles have their nostrils at the ends of their snouts, and phytosaurs had them on raised hump in front of their eyes. Despite the strong similarities between phytosaurs and crocodiles, the two groups are not closely related.

Let us know what answers you found to this week's Challenge. Of course, tell us HOW you found them. We all want to learn from your search strategy.

Hope you find this as interesting and entertaining as I did.

Keep searching!