"[T]he oceans have always belonged to the clams."
At least from a metabolic perspective, according to Earth Sciences Professor Jonathan Payne and his co-authors. The researchers have just published an article in the Proceedings of the Royal Society B: Biological Sciences about the struggle for dominance between brachiopods and bivalves.
When submitting his article for publication, Professor Payne was required by the journal to share any supplementary data associated with the article. The journal accepts small quantities of supplementary data, but not files the size of the databases Payne and his co-authors used for this study. So he turned to the Stanford Digital Repository.
Professor Payne's supplementary data are now available at their own persistent URL (PURL), where anyone interested seeing, analyzing, or reusing the data can freely download them. Payne says that he is happy to have others use the data that they compiled.
Brachiopods and bivalves are similar but ancestrally distinct marine animals with two hinged shells. Both have existed for hundreds of millions of years. The ecological dominance of the two groups has traditionally been determined by looking at their overall numbers, as well as the number of individual species of each type existing at any given time.
Professor Payne's group analyzed how the metabolic activity of these organisms affected their relative ecological importance. They found that bivalves have contributed far more to overall metabolic activity for much broader periods than previously thought. This indicates that instead of there being a shift in dominance from brachiopods to bivalves at the Palaeozoic to Mesozoic transition, bivalves may have actually been the dominant species for much of the time.
In other words, "From the metabolic perspective, the oceans have always belonged to the clams."