The right piece is an Inoceramid showing the home scars of Pseudoperna congesta (holes where the clams encrusted the Inoceramid).  You can tell that it's an Inoceramus shell by looking at the shell in cross-section.  You'll see a fibrous cross-section typical of Inoceramid shells.  I've had people insist that pieces of Inoceramus are bone, because of this misleading look to the shell.  Some times they're beige pieces with suture looking breaks, so it's easy to mistake it. Keith reported: "I also found LOTs of Inoceramus (Platyceramus) platinus (Logan) in the rocks.  This is a longer ranging Ino that can be found throughout the Austin Group in the Dallas/Garland/Richardson area (Atco Limestone, Bruceville Marl, Hutchins Chalk).  In some places, you can see the cross-sections of countless huge platinus's!  This is probably the species in your images with the Pseudoperna congesta (Conrad) home/attachment scars.  Speaking of which, I found countless numbers of those oysters at Spring Creek."

Fossil wood is the most common find on gravel bars in Spring Creek.

AMMONITES

Please help identify this fossil....was located at Beck Branch in Richardson Texas.....a tributary to Rowlett Creek in the same major drainage as Spring Creek. Click on thumbnail to enlarge. Photo taken 2/22/07. Specimen was in rock which had broken off the adjacent cliff face. Looks similar to Parapuzosia americana from Middle Austin Group formation.

This Keith Minor's report on Spring Creek ammonites:

Special thanks to Keith Minor for most of the fossil identifications as well as Rocky Manning's identification.

Keith's website is Cretaceous Fossils  

Fossil Images submitted by Eric Hansen:

 

I would like help identifying teeth, bones, shells, and minerals found in the creek bottom and limestone/shale?/mudstone? strata of the SpringCreek Forest Preserve between Shiloh Road and Holford Road in North Garland.  I have 9 teeth and approx 40 bones I found in June and July of 2005.  The bones are fossilized (no organic material).   I have one bone that is 100% organic, so it appears.  The largest tooth in length is 3-1/2 inches and looks almost like a tusk!  I have a similar one to this but 2-1/2" long.  Both appear to be ivory.  Then, I have some teeth which are much flater and wider than these.  Some with light blue bands.  It appears that some of these teeth may have been fused together when the animal was alive.   Appears to be 2 or 3 species of animals, or more?   Ungulates I presume?      In addition, I have oyster, mussel, scallop-like, and clam shells (some fossils, others not); and some impressive pyrite/pyrite nodules/marcasite specimens, as well as quartz/petrified wood specimens.  And I have a worm-like colony fossil perhaps from a prehistoric shallow sea.

Shells and Pyrites:

Teeth:

Bones:

Other links:

Calcareous Nannofossils - USGS site

Dallas Paleontological Society