4 October 2011

Tall tail

Posted by Callan Bentley

Okay, so I was out photographing ripples and admiring lichens, and then I saw this:

That’s a rippled slab of sandstone, but with a linear groove that obliquely cross-cuts the ripple marks. Smaller, parallel grooves lie within the main groove.

Here’s another look at that same one, spun around and zoomed-in:

It looks as if something was dragged through the wet sand at this location, prior to its lithification. Given the proximity to dinosaur fossils that Virginia Museum of Natural History paleontologist Butch Dooley was excavating, and given my earlier discovery of large concave structures that may be sauropod footprints, the thought that sprung to my mind was whether this could be a case of a dinosaur tail being dragged through the sediment. I know that modern interpretations of dinosaur posture have their tails held high rather than dragging in the dirt, but that’s the image that came to my mind regardless.

Here is a second example. Same thing:

Same one, spun around and zoomed-in:

What do you think about this: What kind of trace fossil is this (assuming it’s a trace fossil)? I’d especially like to hear from anyone with paleontological expertise.