Not sure if it could be a plant but I think it's more likely a skull of some kind of animal.
6" x 4" x 3"
Unknown
Fossiliferous Limestone Display
Unknown Age
Unknown Provenance
Fossiliferous limestone sections often contain larger fossils or fossil traces. From the images; it appears this specimen has areas of an impression of some type of plant material or possible bone. In other areas a fossilized bone structure does appear to be a relief, set out from the matrix. Negligible color differences between the fossil and matrix. It is difficult to identify the form. If animalia: the form is a possible partial marine animal skull, with smaller teeth, as no denture is visible. This could be an example of an endochondral limb section; with interspersed geologic concretions or chert nodules. No apparent cracks across the fossil or matrix, with no filling or repairs noted. Unable to verify its authenticity from images. The item does not have excavation sight information or previous sales records. Item is cut into an oval shape for a flat surface display. Section size: 6" x 4" x 3", unknown weight. It is important to recognize local, state, and US federal laws and prohibitions of sale and shipment of Fossils and Paleontology items.