A good example of covergent evolution is the phyotsaurs.

They look like such kind of crocodile-ish thing, perhaps with a narrow nose like a gharial.

Smilosuchus adamanensis

For a long while, folks thought that phytosaurs were ancestors of crocodiles but more recent evidence has shown that they are not closely related.

The early Crurotarsi were not very crocodile looking: somewhat lizard like with rounded snouts and broad bodies. The Crurotarsi diverged about 250 million years ago, into the phytosaurs and the archosaurs. The phytosaurs fairly rapidly evolved the above crocodile-like appearance and then became extinct around 200 million years ago.

Meanwhile the archosaurs, the “sister taxon” of the phytosaurs, underwent quite a different evolution. It diverged separately into bird-line archosaurs and crocodile-line archosaurs, but neither of these contained members that looked terribly bird-like or crocodile-like for tens of millions of years. The crocodilians developed to have much the same shape, and it seems diet, as the phytosaurs.

Good stuff. Shows how the solution to an amhibious lurking predator arrives at the same solution. Eye location, tail configuration, streamlined mouth of that size, stumpy powerful legs so thay can lurk low and pull back something from the waterline. Not sure where the armour comes from unless it is protection from other ummm crocodile things.

The serrations on the tail are shared as well, not sure why that should be so, maybe they create little vortices for some reason.

AwesomeO said:

The serrations on the tail are shared as well, not sure why that should be so, maybe they create little vortices for some reason.

Probably hurt if you got hit by it

I don’t give a fuck if it is covergent evolution. My local Katter’s Australian Party representative is going to be getting a stern letter.

Were they on the Papuan side of the Wallace Line?

Peak Warming Man said:

Were they on the Papuan side of the Wallace Line?

They ranged quite widely

dv said:

Peak Warming Man said:

Were they on the Papuan side of the Wallace Line?

They ranged quite widely

Did they phyt a lot?

roughbarked said:

dv said:

Peak Warming Man said:

Were they on the Papuan side of the Wallace Line?

They ranged quite widely

Did they phyt a lot?

I cannot say.

dv said:

roughbarked said:

dv said:

They ranged quite widely

Did they phyt a lot?

I cannot say.

From the look of them they’d put up a good phyt.

Where did my post go? OK, I’ll try again tomorrow.

Thinking some more about those serrations on the tail, because the tail moves from side to side maybe they breakup the water movement so that there is not a visible wake or eddies on the surface from that tail moving just underneath.

AwesomeO said:

Thinking some more about those serrations on the tail, because the tail moves from side to side maybe they breakup the water movement so that there is not a visible wake or eddies on the surface from that tail moving just underneath.

There is no evidence that phytosaurs had such serrations. My thought is that the serrations just mark the ends of tail bones.

A great pair of science-blog articles on phytosaurs.

https://blogs.scientificamerican.com/tetrapod-zoology/phytosaurs-mostly-gharial-snouted-reptiles-of-the-triassic-part-i/

https://blogs.scientificamerican.com/tetrapod-zoology/terrestriality-high-walking-and-dimorphic-snout-crests-phytosaurs-part-ii/

Phytosaur portraits

Old-style cladogram including phytosaurs (from 1991). The phytosaurs are included as D. More recent cladograms take phytosaurs out of the archosauria and back among the early archosauriformes.

See how some of these critters, H, I, J, K were bipeds, possibly even C.

I was just going off the picture. I thought about the serrations being a product of the way scales form but they also vary in height (in the picture) in the area where I would expect the greatest water disturbance to occur. I also thought if both developed such serrations it must have a reason for being.

AwesomeO said:

I was just going off the picture. I thought about the serrations being a product of the way scales form but they also vary in height (in the picture) in the area where I would expect the greatest water disturbance to occur. I also thought if both developed such serrations it must have a reason for being.

They had rows of bony armored scales along the spine. Not sure exactly how their exterior would have looked but seems fair to say it would be have been somewhat jagged.

http://www.ucmp.berkeley.edu/taxa/verts/archosaurs/phytosauria.php

Another “group” that had crocodile-like members was the Labrinthodonts – amphibians.

Michael V said:

Another “group” that had crocodile-like members was the Labrinthodonts – amphibians.

(Checks web)

Golly, you’re right. I had thought that all the Labyrinthodonts had really wide heads, like koolasuchus from “walking with dinosaurs” and like modern day giant salamanders.

Here is a reconstruction of Platyoposaurus, a crocodile-like Labyrinthodont.