From ESCONI Yahoo News Group via Dave –

From the Karoo Basin of South Africa. The authors used non-destructive
X-ray synchrotron computed microtomography to probe fossilized burrows.

Summary at: http://www.scienced aily.com/ releases/ 2013/06/13062215 4602.htm

Full on-line article at: http://www.plosone. org/article/ info%3Adoi% 2F10.1371% 2Fjournal. pone.0064978