Ancient mass extinction of fish may have paved way for modern species

[n2doc]

A report looks at a 360-million-year-old gap in the fossil record and finds that marine vertebrates were recovering from an extinction event on par with the one that killed the dinosaurs. What happened is unclear.


By Amina Khan, Los Angeles Times
May 17, 2010 | 5:56 p.m.


Modern-day lizards, snakes, frogs and mammals — including us — may owe their existence to a mass extinction of ancient fish 360 million years ago that left the oceans relatively barren, providing room for marginal species that were our ancestors to thrive and diversify, paleontologists said Monday.

The report, by University of Chicago researchers, focused on events at the end of what is commonly called the Age of Fishes, which lasted from 416 million years ago to 359 million years ago. That age was followed by a 15-million-year period of relative silence in the fossil record.

Paleontologists had tended to ignore the rarity of fossils from that period, which is known as Romer's gap — assuming that the fossils just had not been found, or shrugging it off as an unusual period of low diversity. But in a paper published online Monday in Proceedings of the National Academy of Sciences, the authors proposed that Romer's gap is a sign that the world's marine vertebrates were recovering from a global-scale extinction event.

That gap left ocean niches bereft of weird, now-extinct fishes like the giant armor-plated Dunkleosteus that had ruled the seas up till then, permitting then-marginal species such as sharks to gain ascendency, scientists said. If they had not, the forms of vertebrates existing today may have been very different.

more

http://www.latimes.com/news/science/la-sci-fish-20100518,0,203315.story

[Vinnie From Indy]

1. Probably an early ancestor of British Petroleum did it

[Greyskye]

2. See, the spill isn't that bad!

Fishy analogs will again fill the oceans in a mere 15 million years!