A ‘Cambrian Explosion’ needs more than just sheer numbers - it needs tremendous diversity and variety.  While there are certainly signs of diversification,  the more remarkable aspect of today’s environment seems to have more to do with how many startups there are and not how many different startups there are.  

From The Cambrian Explosion of Startups: 

The sheer number of new startups forming and getting funded these days is dizzying. It’s never been easier to start a company to harness new technologies and turn them into products. Traditional venture capital may not even be able to keep up with it. We are at the beginnings of what may very well become a Cambrian Explosion of startups, which will have implications well beyond the technology industry to the entire economy.

futuresagency:

Click image to display full graph. (via Jonathan MacDonald)