Imagine watching a movie where every now and then, key frames have been cut out. The film seems stilted and disjointed and you have to rely on logic to fill in the gaps in the plots. Evolutionary biologists face a similar obstacle when trying to piece together how living species arose from their common ancestors. It’s like watching a film with a minimum of footage; the species alive today are just a few frames at the very end, and the fossil record represents a smattering of moments throughout the film’s length.

But the gaps, while plentiful, are being slowly filled in. With amazing regularity, new fossils are being unearthed that bridge the gap between existing specimens. These