I believe the specimen shown in the attached photos fell from a dump truck removing spoil from home excavations up the street from my residence in Gainesville, Prince William County, Virginia. This area lies within the Triassic-Jurassic Culpeper Basin.
The specimen weighs 1.5 kilograms has a circumference of 33cm along its major axis, and 29cm along its minor axis. Based on images that are available on the INTERNET, I surmise that this is a fossil sponge. That said, I have absolutely no background or experience in Geology or Paleontology and would appreciate any information or insights members of this forum might be able to provide.