Last summer at a wedding, I met a paleontologist studying ancient crocodiles and his story was fascinating:

Before the K-Pg extinction, Crocodilia was a pretty wide order, with many different species occupying multiple ecological niches, from herbivore crocodiles with teeth like cows', to cat-sized running crocodiles living in the desert. And during the K-Pg extinction, most of it disappeared with only a handful species remaining, occupying two really close ecological niches (semi-aquatic opportunist predators and semi-aquatic fish eater (gharial and galse gharial)).

And he contrasted this collapse with what happened to dinosaurs (also know as birds), which today still have thousands of species occupying almost every possible ecological niche.

What happened at the K-Pg limit with dinosaurs and crocodiles is similar, both went from being very wide to a handful of species remaining. The difference is what happened afterwards, when the few (single?) species of dinosaurs that remained diversified into what we now call birds.

The interesting thing from the article is that crocodiles are still evolving rapidly, but not diversifying! they seem to be successful in their narrow and specialist niche.

I wonder how close crocodilians were to being extinct after the K-Pg limit. If they did, they would be another non-dinosaur archosaurian group only known from fossils, like pterosaurs. Someone from such timeline would probably be delighted to see alive, as seeing one would be the as amazing for them as seeing a pterosaur or triceratops would be for us.

They're the last living non-avian archosaurs. We sure take crocodilians for granted.

That sort of aquatic ambush predator niche has always been very successful, so I think we'd end up with a similar animal with a similar body plan that would fill the niche; it's evolved many times before.

https://bmcecolevol.biomedcentral.com/articles/10.1186/1471-...

I can strongly recommend the recent In Our Time podcast (subscribe, it's a hidden gem!!) episode over this very subject:

https://www.bbc.co.uk/programmes/m000zmhf

I was about to recommend the same thing. This was a great episode in an already great series!

It's basically Joe Rogan for smart and sane people. None of the grifters, all of the scientists + academics. Been going on forever, covering a huge range of subjects.

Joe Rogan? Was interested, now no longer. Using Joe Rogan to describe a podcast cheapens your pitch. Unless your saying the podcast is trying to have incredibly broad appeal without much consideration to intelligent thought or the impacts of what they are putting out to the world except in order to increase their own viewership numbers.

Joe Rogan occasionally has some super interesting podcasts where he invites an academic/expert or two out to talk about their specialisation. He listens, occasionally asking a question.

That's how I first encountered him - he was interviewing John Carmack. The later episodes were disappointing, but I spent a year keeping an eye on the guest list. There were maybe 4-5 really good interviews in that year.

In Our Time is like those good episodes but with an extremely high signal-to-noise ratio and generally better.

It's a wonderful podcast. It's nothing like Joe Rogan. Here's the episode list:

https://www.bbc.co.uk/programmes/b006qykl/episodes/player

And note that when you click to an episode to see who the guests are (usually three professors or other experts on the given topic) there's also a reading list.

I guess it's similar to Joe Rogan's show in that it's a recording of people speaking.

Yah just listened to the first one on the Manhattan project. Its really great, nothing like Joe Rogan. Thanks OP for the great find.

It does have a Uk lean to it, but very understandable and not too heavy at least in the first one.

Thanks for this I'll check it out

I recommend the recent “The Evolution of Crocodiles” episode of In Our Time.

https://www.bbc.co.uk/programmes/m000zmhf

Seconded, should have read further before posting the link myself :)

I love this podcast so much, on some of their way older ones you can hear melvyn bragg making weird mouth noises if you listen closely

He's always been notably snuffly.

I listened to that the other week and can also highly recommend.

"crocodiles have changed dramatically in the last two million years" is a pretty important statement to keep in mind. Whenever we discuss modern animals and traits that are evolving, it's a bit misleading to not apply the time frame.

I did expect this to be about them reacting to climate change and other human factors, as there's been many stories like this recently. But I suppose a couple million years is a blink of the eye for a family this ancient.

A common example of repeated convergent evolution: https://en.m.wikipedia.org/wiki/Carcinisation

Brace for crococrabs !

Off topics but it’s pretty interesting that Nile crocodiles are now in Florida.

They’re big and they eat people.

We have Saltwater Crocodiles too

Just be glad it's not the 40ft long "terror crocodile".

I never understood why they don’t eat more birds. You’d think they could come up underneath and grab a duck or goose. And I always see birds just hanging out nearby.

Smaller birds have a symbiotic relationship with crocodiles. The crocs get teeth cleaning and the birds get to eat.

I'd guess these birds can sense an approaching croc.

Maybe because there’s just not that much meat on them bones? If it was a nice fat juicy chicken, sure, but a river rat bird?

Soon they will start a popular startup incubator and change VC investing as we know it

It seems like the issue is your lack of understanding of evolution, not the article’s choice of title. Evolution doesn’t work like in The X-Men.

>“Modern Crocodiles Are Evolving at a Rapid Rate: Despite their reputation as ‘living fossils,’ crocodiles have changed dramatically in the last two million years”

So, "Modern", is how long?

Is “modern” a technical term in biology/palaeontology, or is it just meant in the ordinary sense? Asking because I don’t actually know. In history, “modern” is a technical term - it refers to the period beginning in 1500 (approximately) - which is a bit different from the everyday meaning, the average person would probably not call the 1500s “modern”.

It depends. Half a second is a long time for code to respond to an API request. Half a million years is a short time to a geologist.

2 million years isn't too long considering how long they have been around