#fossil tree

And that's sandstone behind it. But not dunes, because there's no crossbedding. I think maybe water put it here. There's flowy bits.

Horseshoe crab tails? But some are too big. Plant stems? Again, some seem a little large. Or just some weird rust discoloration from ore, or a very odd sort of mineral that grows like a crystal without being quite regular in shape? But growing in sand/silt? instead of a fluid-filled cavity? Can that happen?

And then there's this. Small tracks on either side of a tail drag? Or a rolling pebble with water ripples on either side?

Fas t forward to May 2021. Vaccinated. Return to St George to meet parents. Visit St. George Dinosaur Discovery museum, which has some of the best-preserved dinosaur tracks in the world on ancient silty mudflats, including a bona-fide dino butt print where a dino sat down on its haunches and then wandered off.

I show my photos to a paleontologist working the desk, and she says, "Oh, that's just petrified wood."

Just. Because it's common in this part of the southwest.

So we go home and I show Mom the rock face. While we're standing back, she points out they're part of an entire fucking TREE lying on its side, branches fanning to the right, partly embedded in the cliff, partly eroded out of it leaving a light imprint in the siltstone.

That dark horizontal bit above the right side of the yardstick is the petrified skin of a treebranch (debarked, I think; there's other places that show a bumpy bark imprint whereas the brown petrified wood bits are smooth.) I think the "tail drag" mark might be a conifer twig with needles.

So I posted THESE to Twitter's #fossilFriday, and the curator of the museum spotted it and said he'd come by to document it, although I don't think he has yet because it's not in a very good state of preservation. Quoth he:

I agree with your identification as a portion of a tree with branches, and trees are very common in the Late Triassic Shinarump Member of the Chinle Formation buried in braided river systems some 230-225 million years ago. Unfortunately, from what I can see from your photos, most of the fossil is missing and I can't make out anything identifiable.

— Dr. Andrew Milner

Which means it just barely postdates the last survivors of the Permian die-off, my buddy Lystrosaurus, but not by much! (wrong part of the world, anyway; this isn't Gondwanaland.)

And after that email exchange I kept searching the cliff and found at least one more tree fossil as well. It's very definitely fossil treeroots from a tree that's lying on its side, but unless the top broke off and is not lying quite at the same angle, it's probably a second tree. It's behind the edge of my parents' neighbors' yard, so hopefully it's well-protected.

More bits of petrified wood from the first tree.

[Most photos May 8-9 2021]

And I'm just stoked, you know? I'm not a geologist, although there's lots of scientists in my family, and my maternal grandfather taught geology at a junior college. I've just gotten interested in this as a hobby of the past 10 years.

And there it is. An honest to gosh fossil tree, maybe one of the first to grow tall again after the end Permian extinction, shading the silty flats of a wide river down to what became lakes or the inland seaway. The first dinosaurs trotted past it, leaving tracks in the silt. That's a real tree that lived for decades or hundreds of years, and it moved in the wind and felt the rain, hundreds of millions of years ago, when the animals and insects that scurried on its bark were almost entirely different from today.