Jump to content

Trachyscaphites spiniger porchi


Uncle Siphuncle

Recommended Posts

Producing exposures of Pecan Gap chalk in South Texas seem to be getting scarcer by the year, but I visited one recently that was worth my while.  

 

This friable, conchoidally fracturing beige chalk weathers readily, so I was able to blind mine bare handed like a hungry bear ripping apart a log to get to the honeycomb.

 

My efforts turned up a couple Trachyscaphites ammonites, shown here in the raw.  Enjoy.

81EB2597-AD08-4B5C-A96F-5C82BD2DDB60.png

6BC1BA4F-E1C8-436C-9D8F-88F99E2C6D69.png

Grüße,

Daniel A. Wöhr aus Südtexas

"To the motivated go the spoils."

Link to comment
Share on other sites

Nice finds! Lovely specimens. I find Scaphites cf. hippocrepis specimens in the Austin Chalk quite regularly. Very interesting ammonites. 

Link to comment
Share on other sites

Uber cool! :) 

    Tim    VETERAN SHALE SPLITTER

   MOTM.png.61350469b02f439fd4d5d77c2c69da85.png      PaleoPartner.png.30c01982e09b0cc0b7d9d6a7a21f56c6.png.a600039856933851eeea617ca3f2d15f.png     Postmaster1.jpg.900efa599049929531fa81981f028e24.jpg    VFOTM.png.f1b09c78bf88298b009b0da14ef44cf0.png  VFOTM APRIL - 2015  

__________________________________________________
"In every walk with nature one receives far more than he seeks."
John Muir ~ ~ ~ ~   ><))))( *>  About Me      

Link to comment
Share on other sites

How many species of scaphites are there to be found in the Austin chalk and Eagleford?

Mine have been coming out of the Eagleford, Aradia Park and Britton members.

I don't recall ever finding any in the Austin stuff.

You got a couple of goodies there.

 

Jess B

 

 

Link to comment
Share on other sites

Gonna look real nice prepped! :ammonite01:

Every single fossil you see is a miracle set in stone, and should be treated as such.

Link to comment
Share on other sites

16 hours ago, bone2stone said:

How many species of scaphites are there to be found in the Austin chalk and Eagleford?

Mine have been coming out of the Eagleford, Aradia Park and Britton members.

I don't recall ever finding any in the Austin stuff.

You got a couple of goodies there.

 

Jess B

 

 

Not sure about the Eagle Ford, but in the roughly middle Coniacian stage of the Atco I have found only one Scaphites species so far, probably S. hippocrepis. However, 2004 Stinnesbeck et al. reports 4 other species from a unit in the Austin a bit older than mine in the lower Coniacian: Scaphites (Scaphites) uintensisS. (S.) frontierensisS. (S.) sagensis, and S. (S). cf. S. (S.) preventricosus. There may very well be more Scaphites species in the middle Coniacian Atco. I just haven’t found them yet. 

Link to comment
Share on other sites

13 hours ago, bone2stone said:

How many species of scaphites are there to be found in the Austin chalk and Eagleford?

Mine have been coming out of the Eagleford, Aradia Park and Britton members.

I don't recall ever finding any in the Austin stuff.

You got a couple of goodies there.

 

Jess B

 

 

I don’t know the whole Scaphitid lineage with great specificity off top-of-head, but I believe I’ve seen some form of Scaphites in a pyritized micromorph zone low in the Duck Creek fm, then Eoscaphites in the Del Rio fm.  The first similar form that pops into head in in the Britton is Yezoites.  I found the nifty little guy shown below while scouting for sites low in the Austin Grp.  Scaphitids seemed to flourish in Texas seas in the Campanian Anacacho, Pecan Gap, and Ozan fms, then finish out the Maastrichtian with Discoscaphites and maybe others.

 

As for prepping Pecan Gap ammonites, I’ve learned the hard way that sometimes what you see is what you get.  The chalk and fossil don’t always separate well.  Separation is best when split rather than scribed.  I’ve had best success by sawing the block down close to the ammonite, hoping for a faint plane of separation to appear normal to one of the side planes that I can exploit with a single, surgically directed chisel shock.  Still, this perilous gamble has destroyed as many ammos as it has revealed.  Look at the Pecan Gap cross eyed and the stuff explodes.

6FA8FDBC-96F8-4F29-956B-2630534D89AD.jpeg

Grüße,

Daniel A. Wöhr aus Südtexas

"To the motivated go the spoils."

Link to comment
Share on other sites

Sounds like it takes a brave person to prep chalk fossils out of a chalk matrix!

 

Fingers crossed for prep

Link to comment
Share on other sites

On ‎4‎/‎22‎/‎2018 at 8:39 AM, Heteromorph said:

Not sure about the Eagle Ford, but in the roughly middle Coniacian stage of the Atco I have found only one Scaphites species so far, probably S. hippocrepis. However, 2004 Stinnesbeck et al. reports 4 other species from a unit in the Austin a bit older than mine in the lower Coniacian: Scaphites (Scaphites) uintensisS. (S.) frontierensisS. (S.) sagensis, and S. (S). cf. S. (S.) preventricosus. There may very well be more Scaphites species in the middle Coniacian Atco. I just haven’t found them yet. 

Thank you for the reply.

I have been working on a method of cataloging and separating my collection and information such as this is very helpful

 

Jess B.

Link to comment
Share on other sites

On ‎4‎/‎22‎/‎2018 at 9:50 AM, Uncle Siphuncle said:

I don’t know the whole Scaphitid lineage with great specificity off top-of-head, but I believe I’ve seen some form of Scaphites in a pyritized micromorph zone low in the Duck Creek fm, then Eoscaphites in the Del Rio fm.  The first similar form that pops into head in in the Britton is Yezoites.  I found the nifty little guy shown below while scouting for sites low in the Austin Grp.  Scaphitids seemed to flourish in Texas seas in the Campanian Anacacho, Pecan Gap, and Ozan fms, then finish out the Maastrichtian with Discoscaphites and maybe others.

 

As for prepping Pecan Gap ammonites, I’ve learned the hard way that sometimes what you see is what you get.  The chalk and fossil don’t always separate well.  Separation is best when split rather than scribed.  I’ve had best success by sawing the block down close to the ammonite, hoping for a faint plane of separation to appear normal to one of the side planes that I can exploit with a single, surgically directed chisel shock.  Still, this perilous gamble has destroyed as many ammos as it has revealed.  Look at the Pecan Gap cross eyed and the stuff explodes.

6FA8FDBC-96F8-4F29-956B-2630534D89AD.jpeg

Nice to know that there are some things out there that I have never seen .

This Austin Chalk specimen is a dandy. Never seen one and I have hunted the Austin for 30+ years.

I have several scaps from the Dallas/Ft Worth area along with the Pecan gap and Del Rio stuff.

You are absolutely right about the Pecan Gap material took three days to clean two specimens from the matrix.

I had to piece one of them back together twice!

Thanks for the info along with other helpful hints I think I can get a pretty good grouping of tagging for my scaphs.

Got a few from the Paw Paw that look amazingly like the Britton member stuff.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...