Which came first, Facebook or sharks?

sharks came first, by 450.002 million years. Shark-like fish were swimming the oceans in the Ordovician.

Side by side

Facebook

Facebook launched on 4 February 2004 restricted to Harvard email addresses, opened to other universities through 2004 and 2005, and to anyone over 13 with an email address in September 2006. It is six years younger than Google and a year older than YouTube. Its predecessor Facemash, which compared students' photographs, was shut down by the university within days in 2003.

sharks

Scales from shark-like fish appear around 450 million years ago and unambiguous shark teeth by about 420 million years ago. The first trees appeared roughly 385 million years ago, so sharks predate trees by tens of millions of years. They also predate Saturn's rings on most current estimates, and they have survived all five mass extinctions.

Deep-time dates are approximate to within tens of millions of years and shift as new fossils are found.