"Several hours of evolutionary history" Topic

Time to nerd out on taxonomy, evolutionary biology and paleontology.

This series show just how much we know, and just how massive the fossil record actually is.
YouTube link

The fossil record may be massive – but I attended a
lecture 3 years ago by a paleontologist who offered
the opinion that for as long as critters of a certain
size (he mentioned as large as field mice) had stalked
the planet, there don't seem to be enough fossils.

Of course, he also went into great detail as to why
that may be (geologic activity; thaw/freeze; inhospitable
soil conditions; scavenger species [including proto-
humans using bones for tools !] etc.)

The fossil record is surely massive and getting bigger all the time. But it is also a very small percentage of all the creatures that ever lived.

As Ed's paleontologist explains, it is hard to make a fossil. It is also easier to produce a fossil of a large dinosaur than one of the small mammals that lived at the same time. Little creatures, the size of a mouse, would have had a huge amount of predators. Many would have died, chewed up in someone's maw. Those that didn't were chewed up and dispersed by scavengers. Larger dinosaurs bones would have stayed closer together even though the same processes are at play. Also in the field today, large fossils are easier to spot.

How many complete little mammal fossilised skeletons from the Cretaceous have any of you seen? I can't think of one and I've been to a few museums.