• Collection:    cf.com
• Formation:   Washita Group, Pawpaw Formation
• Location:      Grayson County, Texas

The many impressions at the base of the Pawpaw were originally described as jellyfish (See Caster, 1945 below). However, Fürsich & Kennedy (1975, reference below) have argued that it's actually a trace fossil on the grounds that:

• 1) Known fossil medusoids are never preserved as body fossils, as far as is known.
• 2) The type of environment in which the Pawpaw was deposited was not likely to be conducive to soft body preservation (known jellyfish trace fossils are known to have been formed only under extraordinary circumstances).
• 3) The impressions consist of stacked lobes that cut across the sediment laminae instead of disturbing the layers, indicating that the impressions were made after the clay and sand were deposited.  They suggest that a feeding trace called Gyrophyllites has this branched-lobe, stacked-lobe pattern and is a more likely explanation for the impressions. 

What actually made this is anybody's guess.  Fürsich & Kennedy also explained some grainy features on Caster's holotype as being pellet-lined burrows similar to Granularia (probably crustacean, as they commonly line their burrows with their fecal pellets) mixed in with the impressions, so Caster's holotype is an unusual combination of burrows made by more than one critter.

• 1876 ? Discophorites Hee

• Found occasionally in the Cretaceous

• Gyrophyllites is reported to range from the Devonian to Tertiary Period

• Worldwide

• Caster, K. E.  1945.  A New Jellyfish (Kirklandia texana Caster) from the Lower Cretaceous of Texas.  Palaeontographica Americana 3 (18), 1–42. 
• Additional photos can be found in:  Finsley, C. F.  1989.  A Field Guide to Fossils of Texas.  Austin:  Texas Monthly Press, plate 3, color photo 6.
• Fürsich & Kennedy. 1975.  Kirklandia texana Caster-Cretaceous Hydrozoan Medusoid or Trace Fossil Chimaera?  Palaeontology 18 (4), 665–679.
• Hass, W. H.; Häntzschel, W.; Fisher, D. W.; Howell, B. F.; Rhodes, F. H. T.; Müller, K. J.; Moore, R. C.  1962.  "Part W.  Miscellanea (Conodonts, Conoidal Shells of Uncertain Affinities, Worms, Trace Fossils, and Problematica)".  In:  Moore, R. C., ed.  Treatise on Invertebrate Paleontology.  New York and Lawrence:  Geological Society of America and University of Kansas Press, W200; fig. 122,3a & b.