Any ideas what this is? Found in a creek bed near Austin Texas

[Rossie7]

Thank you for the help, looking forward to hearing what this is.

[Al Dente]

It is a rudist.

[Rossie7]

thank you!

[mohsenamini]

It is a rudist.

it should be Scleractinia. how do you say it is a rudist?

[JohnJ]

It is a rudist.

I agree with Eric. This is an eroded Durania or Saugavesia.

[mohsenamini]

I agree with Eric. This is an eroded Durania or Saugavesia.

well i just want to know how you think this is Rudist? you have reasons or just guessing?

i have reasons. look at calyx there are some horizontal plates on septa.

[Al Dente]

well i just want to know how you think this is Rudist? you have reasons or just guessing?

i have reasons. look at calyx there are some horizontal plates on septa.

Some rudist have a very coral like appearance to their shell but there are some differences in the structure. Some rudist have cube shaped cells unlike a coral. You can see that in this example. These rudist also had a round hollow area in the shell where the animal's body lived. You can see part of it in the first post.

Here is a close up of a piece of rudist shell showing the texture-

This picture is from this thread-http://www.thefossilforum.com/index.php?/topic/42318-marine-fossil-formation/

Here is a more complete rudist that you can see some of this texture-

This is from a pretty good thread showing a variety of rudists-http://www.thefossilforum.com/index.php?/topic/11858-show-your-rudists/

[abyssunder]

Here you can see the schematic morphology of the two : Coral Rudist
Also here are examples of rudists including Durania, in e you can see the resemblance with the specimen in question :

Edited March 22, 2016 by abyssunder

[mohsenamini]

Here you can see the schematic morphology of the two : corals.jpg Coral Radiolites.jpg Rudist

Also here are examples of rudists including Durania, in e you can see the resemblance with the specimen in question : CJES45-04-SkeltonClassification.jpg

1e.jpge.jpg

ok guys i gave you the reason that how this is Coral but cant proof more

Also I asked 3 professors that i know about this and some other experts. this is Coral for sure.

here are professors (they are experts on Corals) you can contact:

1- Bernard Lathuilière (France)

2- Shaahin Zaman (France)

3- Kebriayi zadeh (Iran)

please check the names in this website: http://www.corallosphere.org

So i think we can't argue more on this sample

Edited March 22, 2016 by mohsenamini

[Al Dente]

ok guys i gave you the reason that how this is Coral but cant proof more

Also I asked 3 professors that i know about this and some other experts. this is Coral for sure.

here are professors (they are experts on Corals) you can contact:

1- Bernard Lathuilière (France)

2- Shaahin Zaman (France)

3- Kebriayi zadeh (Iran)

please check the names in this website: http://www.corallosphere.org

So i think we can't argue more on this sample

The only coral that this resembles is possibly some type of tabulate coral but they went extinct long before the Cretaceous which is the age of the rocks around Austin. You state it is scleractinian which this doesn't resemble at all. Scleractinian corals will have a round corralite with radiating septae. There is no corralite with this structure on this fossil. Did you look at the links I provided? Do you believe the fossils in the links are also corals?

[JohnJ]

ok guys i gave you the reason that how this is Coral but cant proof more

Also I asked 3 professors that i know about this and some other experts. this is Coral for sure.

here are professors (they are experts on Corals) you can contact:

1- Bernard Lathuilière (France)

2- Shaahin Zaman (France)

3- Kebriayi zadeh (Iran)

please check the names in this website: http://www.corallosphere.org

So i think we can't argue more on this sample

Mohsenamini, it's possible these people are not familiar with the fauna and geology of Central Texas. Rudists are found in the Upper and Lower Cretaceous formations near Austin, Texas. They get tumbled in local waterways and develop a highly eroded surface.

There is a possibility it could be one of the Lower Cretaceous rudists, like Eoradiolites; but I think the Upper Cretaceous Durania or Saugavesia is probable. Here are examples of Durania I have collected in the Austin area.

[DPS Ammonite]

Mohsenamini, I too was fooled by a rudist that I found in the Cretaceous Chalk north of Dallas, Texas. I thought that it was a piece of petrified wood or coral. When I show my rudist to geologists most don't guess that it is a bivalve. Show the fossils in the first post to a rudist or bivalve expert.

Here are two pictures of my rudist, (Durania sp.), which is about 9 cm across. Note the hollow and concave inner surface that is colonized by small oysters. See detail of the right side, a cross section that does sort of look like corralites with septa.

Edited March 22, 2016 by DPS Ammonite

[Carl]

Way to go, TEAM!

[Nuna]

Very informative! Thanks!  How about this one? I was told by a few people it's rudist.  One specifically called it durania.  But it's been called a lot of things, including petrified wood.  Would love for anyone to weigh in, found it in Ladonia, TX at the NSR.