Half_Echinoid Silicified

[Shellseeker]

So I am hunting the Peace River and finding good stuff, like mastodon verts, horse teeth, colorful hemis and into my sieve pops a broken sand dollar...... and I do a little dance ,  got a smile ear to ear , because I am hoping , with a little help from my friends that this this Echinoid will help to identify the formation I am hunting,  maybe Pliocene or middle Miocene. There are a lot of years between them. @Harry Pristis indicated that the silicified shells might more likely imply middle Miocene.  

The echinoid has an interesting shape and no holes.... I think it is possible....

@Coco, @MikeR, @Sacha

 

[IsaacTheFossilMan]

Sorry I cannot help with ID, but that's a stunner!

[Coco]

Sorry, there’s too little of the sea urchin left for me to identify. I can’t say anything more than sand dollar

 

Coco

[Al Dente]

Jack- I can see a periproct above the notch. I think this is Abertella which would be Miocene. I’ll look through my references to make sure.

[Al Dente]

I’ve looked through my references and I’m fairly confident this is Abertella, not sure which species. Here an outline of A. aberti from this website- https://www.nhm.ac.uk/our-science/data/echinoid-directory/taxa/specimen.jsp?id=2233

 

Sacha has a nice A. dengleri that he posted here-http://www.thefossilforum.com/index.php?/topic/80950-abertella-dengleri-echinoid-late-miocene/

 

 

[Shellseeker]

3 hours ago, Al Dente said:

I’ve looked through my references and I’m fairly confident this is Abertella, not sure which species. Here an outline of A. aberti from this website- https://www.nhm.ac.uk/our-science/data/echinoid-directory/taxa/specimen.jsp?id=2233

 

Sacha has a nice A. dengleri that he posted here-http://www.thefossilforum.com/index.php?/topic/80950-abertella-dengleri-echinoid-late-miocene/

  Thank you.  We are well on our way to a specific identification.

I felt that TFF has so many experts of your caliber on Echinoid fossils, that one would recognize the unusual shape or characteristics to get us in the right ballpark, and then it would be the legwork to run down specific species in the Miocene or Pliocene of Florida.

I will be searching for any additional Abertellas in the Miocene of Florida on the internet....

[Sacha]

Jack, I'm confident it is Abertella dengleri from the Peace River formation, Miocene. I got a nice one today in Zolfo. I'l take a picture when the sun come up Saturday.

[Coco]

 

Coco

[hoffy]

If you don't get a positive id you could send a picture to Roger Portell at UF. 

[Shellseeker]

29 minutes ago, Sacha said:

Jack, I'm confident it is Abertella dengleri from the Peace River formation, Miocene. I got a nice one today in Zolfo. I'l take a picture when the sun come up Saturday.

Thanks, John.. Waiting to see what one of these looks like whole.

Thanks to all who moved me in the right direction... @Coco @IsaacTheFossilMan @Al Dente @Sacha

 

So, I am digging in the Arcadia Fm, with stuff from the Pliocene and Pleistocene mixed in.. Just my kind of place....

[Sacha]

OK Jack @Shellseeker, here's a picture of what I've gotten from Zolfo. The 3 on the left, along with the 2 I've sent to Roger Portell, I've gotten in past years. The 3 on the right I got last Monday. They are mostly complete but preservation was poor. The one in the middle I got yesterday. I'm pleased with almost any Abertella that has an intact perimeter. For more info get a copy of Florida Museum Bulletin "Neogene Echinoids of Florida". All 3 Abertella species are discussed in detail.

 

 

Here is a chunk of the stuff I'm looking for below a foot of sand and on top of the whiteish clay. Tough digging around blocks of dolomitic limestone/chert looking for deeper holes that trap these loose prizes.

 

[Shellseeker]

 

13 hours ago, Sacha said:

OK Jack @Shellseeker, here's a picture of what I've gotten from Zolfo. The 3 on the left, along with the 2 I've sent to Roger Portell, I've gotten in past years. The 3 on the right I got last Monday. They are mostly complete but preservation was poor. The one in the middle I got yesterday. I'm pleased with almost any Abertella that has an intact perimeter. For more info get a copy of Florida Museum Bulletin "Neogene Echinoids of Florida". All 3 Abertella species are discussed in detail.

 

 

1st of all, John I respect the expertise you have, the contributions you have made to this forum and to Paleontology.  Truly impressive.

As I compare, I think my find may be Abertella, but I am having difficulty seeing dengleri. Can they be the same species and also be this different?

 

[Plantguy]

9 minutes ago, Shellseeker said:

 

1st of all, John I respect the expertise you have, the contributions you have made to this forum and to Paleontology.  Truly impressive.

As I compare, I think my find may be Abertella, but I am having difficulty seeing dengleri. Can they be the same species and also be this different?

 

Jack, neat find. I looked at this earlier and was questioning the fragment orientation in my own brain and the shape of the petals. I wasnt sure if it was just the level of preservation that was skewing things as it looks like you have the lower part of the critter. I did see there were several diff Abertellas in the db...

Look forward to reading more from you all. 

Regards, Chris 

[Sacha]

8 hours ago, Plantguy said:

Jack, neat find. I looked at this earlier and was questioning the fragment orientation in my own brain and the shape of the petals. I wasnt sure if it was just the level of preservation that was skewing things as it looks like you have the lower part of the critter. I did see there were several diff Abertellas in the db...

Look forward to reading more from you all. 

Regards, Chris 

 

I'm with Chris Jack. Rotate your piece through the 4:00 and 8:00 positions.

[Mahnmut]

Thats an interesting kind of preservation.

I have found sand dollars in Portugal (and bought some) that are all transformed to solid calcite, with perfect cleavage through the whole fossil.

Your specimen here on the other hand seems to have the thin walls preserved and the crystals on top.

Cheers,

J

[Shellseeker]

13 hours ago, Plantguy said:

Jack, neat find. I looked at this earlier and was questioning the fragment orientation in my own brain and the shape of the petals. I wasn't sure if it was just the level of preservation that was skewing things as it looks like you have the lower part of the critter. I did see there were several diff Abertellas in the db...

Look forward to reading more from you all. 

Regards, Chris 

Chris,

It is the shape and orientation of the petals on my fragment that are causing my confusion in comparing to all 5 options for Abertella in the the "Neogene Echinoids of Florida" pdf.

 

5 hours ago, Sacha said:

 

I'm with Chris Jack. Rotate your piece through the 4:00 and 8:00 positions.

I do not know a lot about Echinoids.

 

Here is the A dengleri on the cover of the pdf. I have marked in yellow 4 & 8 o'clock positions. If I broke it on the red lines,  I would see 2 complete petals in the broken segment.

 

 

Here is my broken fragment. I see only 1 petal coming from the center. Is the orientation of the petals on the echinoid relatively fixed or relatively fluid.  If the latter, this is A. dengleri. If the former, it is Abertella, but not necessarily Abertella dengleri. Thanks Jack

 

Edited March 28, 2021 by Shellseeker

[Sacha]

45 minutes ago, Shellseeker said:

Chris,

It is the shape and orientation of the petals on my fragment that are causing my confusion in comparing to all 5 options for Abertella in the the "Neogene Echinoids of Florida" 

 

 

Here is my broken fragment. I see only 1 petal coming from the center. Is the orientation of the petals on the echinoid relatively fixed or relatively fluid.  If the latter, this is A. dengleri. If the former, it is Abertella, but not necessarily Abertella dengleri. Thanks Jack

 

 

 

Jack, all Abertella seem to have the same petal to lobe orientation judging from the photos in the bulletin.....that is 2 petals bracketing the lobe. I see only 3 species in the bulletin and each are found in limited locals. I think your hunting areas and the size of your specimen limit the options to A. dengleri. The one thing that bothers me is that your picture makes the sand dollar look pretty thick. Abertellaa are very thin......paper thin at the edges. It could also be that because of that thinness, your shape is not the natural lobe, but a damaged edge.

 

 

 

 

[Shellseeker]

6 hours ago, Mahnmut said:

That's an interesting kind of preservation.

I have found sand dollars in Portugal (and bought some) that are all transformed to solid calcite, with perfect cleavage through the whole fossil.

Your specimen here on the other hand seems to have the thin walls preserved and the crystals on top.

Cheers,

J

There is a lot of diversity in what I find.

Here is an Echinoid fragment that was a translucent yellow as it came out of the dark water Peace River.

and then we get some of this.  A whelk with multiple transformations... It adds to the pleasure of digging in a multi dimensional site. 

[Plantguy]

Hey Jack, @Shellseeker

Here's the orientation I see for your echinoid....A fair sized fragment has broken off along the edge (green highlighted area) with the upper almost 2/3rds missing. Still a very neat find. Not an expert either but I've seen the Abertellas the guys in the TB club have found and seen John's photos and have looked in the invert db and that new pub. They are great finds and neat critters! Might be worth bouncing a picture off Roger Portell to confirm one way or the other. Let him know/share pictures that you found some other stuff in the echy zone....finding associated critters with the echys is usually noteworthy. 

Also....that gastropod fragment sure looks like a piece of an Ecphora. showing the distinctive 4? ribs? Looks like an interesting mix of stuff you are into! Congrats. 

 

Regards, Chris 

[Shellseeker]

13 hours ago, Plantguy said:

Might be worth bouncing a picture off Roger Portell to confirm one way or the other. Let him know/share pictures that you found some other stuff in the echy zone....finding associated critters with the echys is usually noteworthy. 

Thanks, Chris..  Likely the best next step... I will  post a response of I get one.

[Shellseeker]

15 hours ago, Plantguy said:

Might be worth bouncing a picture off Roger Portell to confirm one way or the other. Let him know/share pictures that you found some other stuff in the echy zone....finding associated critters with the echys is usually noteworthy

Sent Roger the TFF link and photos. A quick, short response,

Quote

Probably A. dengleri but hang on to it so I can inspect more closely.

R