Fascinating new paper describing the findings from fossil sites in China, dated to the Jurassic, including dinosaurs, mammals and amphibians amongst other things.
The majority of fossils that palaeontologists find are preserved in Lagerstätte, these are sites of exceptional preservation, where special circumstances led to the fossilisation of many living things at the same time.
This example is particularly impressive because there are Lagerstätte from the same geographic location, but two different periods in geological history, separated by 30 million years. This means that we can look at how the species and ecosystem changed and evolved in that 30 million year span. This succession is pretty much unique in the fossil record, particularly for vertebrate animals, and so is very exciting!
You can read a summary (rather than the paper itself) here: http://www.sciencedaily.com/releases/2014/03/140304141728.htm
the Daohugou Biota and the Jehol Biota are two successive Lagerstätte assemblages that collectively offer a taphonomically consistent window into the Mesozoic life of northeast Asia over a significant span of geologic time.