One very occasional issue in palaeontology is the effects of bioturbation. In short, living animals and plants by their action s altering the fossil record in various ways. This can be a herd of sauropods tramping across a muddy area and trampling and destroying existing skeletons, or as undramatic as plant roots coursing through layers of the earth and blurring the boundaries. It can even involve rodents burrowing into the soil and bones from one layer falling into a deeper one, concealing their true stratigraphic position. Here however is an exceptionally mild case, a jerboa sitting on a tyrannosaur scapula. This was (he’s now moved on to bouncy rodent paradise) Xu Xing’s pet, generally refereed to as simply ‘the rat’. I had occasional jerboa-sitting duties and he was allowed to hare around the office at high speed and occasionally interact with fossils (note, no damage was ever done!). Especially keen-eyed readers may have spotted him before – he lives on as a mascot on AAB.
[The pink tones comes from a broken camera].