Fossils - Exposing the Evolutionist slight-of-hand

Out of curiosity, how within a creationist model
do you account for the huge discreprancy in numbers
of vertebrate and invertebrate fossils ?In the evolutionary model it's straightforward, the
invertebrates have been around much longer and so have
had greater opportunity to be represented in the fossil
record.

I did wonder whether the answer might come back as
'well there are more of them.' but I'm not entirely
convinced that would satisfy such a vast discreprancy
in the numbers of finds.