What does "pre-dating" mean?

present participle and gerund of pre-date

What is a synonym for "pre-dating"?

Common synonyms include: antedating.

verb

verb ·Rare ·Advanced level

Verb

1
present participle and gerund of pre-date form-of, gerund, participle, present

"Sharks have been around for 400 million years, pre-dating the dinosaurs. But scientists believe they may be unable to survive this ongoing assault."