Cambrian explosion - could it be influenced by aliens?

I don't have any sources with evidence or anything, but the Cambrian explosion is a really strange period in Earth's history that stands out. Most of the species during that period just came like from nowhere, they had no ancestors, so that questions the Evolutionary theories. In addition, some of these animals looked like nothing before or after, e.g. the so-called Opabinia that had 5 eyes:

Judging by the looks only, it looks pretty alien. The number of eyes is striking as most Earth creatures have an even set of eyes.
Could some or all of the life forms that flourished during that period be alien to the Earth? Is it possible that they get transported here by an asteroid or something?

Looks like the alternate dimension at the end of Half-Life for PC.

anything is possible.

but its not probable that so many life-forms could be deposited here, alive from an asteroid or meteor.

and there is nothing to say these things cant be genetic abhorrations under evolution? perhaps the earths magnetosphere had reduced, allowing more radiation in, and more/varied genetic mutation.

weird things happen when radiation gets in the crib!

It has been postulated it could have been a gamma ray burst that lead to one of Earth's earlier extinctions.

Gamma Ray Burst

Well heck... with all the aliens that are flying around our skies I would imagine that when the sneeze, spit, take a leak or flush their spacecraft toilet dumps that they might leave a few odd things lying around that might thrive...

Absolutely, it could

I would re-check what the latest research on the so-called 'cambrian explosion' is - I know it has been extensively revised since it first became popularised. Not so explosive as first thought and the supposed bizzare forms re-classified as parts of other creatures.

I would like to state it clear that I'm not in either the Creationist, Intelligent Design or Evolutionary crowd. I don't have any firm beliefs. On a less serious note, I wish we still had some of these strange creatures because for me most of the present-day creatures are so generic and boring, compared to those ancient ones. Maybe that explains my interest in Paleozoology and Cryptozoology. Saying that, I like species that are unique or strange on themselves, I'm not that fond of anomalies in individuals when it comes to animals, because most of them suffer. It would have been good if more of the ancient species survived the extinction events (save for the most dangerous ones ), but, well I guess Earth knows best.