I showed Jeffery P  the Jacksboro spillway on his swing through Texas and it was my day to find plants in this otherwise marine site. At least I think that both are plants. First this piece with mm scale which I'm guessing could be Cordaites or Artisia pith.     Edge view     and close-up     and other side   Next this leaf which I think is one of the seed fern pinnules, also with mm scale