1. Quantification of Cenozoic Marine Primary Productivity through Geochemical Analysis of Marine Mammal Bioapatite
Mark T. Clementz, Dept. of Geology & Geophysics, Univ. of Wyo.
Pezosiren
Dorudon
Marine
(Today)
Rodhocetus
Indohyus
Marine
(Today)
Pakicetus
Freshwater
(Today)
Freshwater
(Today)
Members of the sister taxon (Raoellidae: Indohyus) to whales were semiaquatic, but mostly fed on land.
Trophic position was high: 3rd to 4th order consumers
By 50 Ma, foraged in freshwater habitats (Pakicetus)
By 46 Ma, foraged in nearhsore marine habitats (Rodhocetus, Dorudon)
Favored highly productive waters close to shore
Early sirenians were marine consumers of seagrasses with little evidence of freshwater plants in their diets
Sirenian trophic position was low and stable: 1st order consumers
Favored shallow water marine habitats

2. Quantification of Cenozoic Marine Primary Productivity through Geochemical Analysis of Marine Mammal Bioapatite
Mark T. Clementz, Dept. of Geology & Geophysics, Univ. of Wyo.
Metaxytherium
Marine
(Today)
Metaxytherium
Marine
(Today)
Freshwater
(Today)
Freshwater
(Today)
In the Neogene, sirenians (yellow) exhibit a greater dietary range than that for Paleogene species (gray)
First evidence of freshwater diets from the Middle Miocene.
Sirenian trophic position was low and stable: 1st order consumers
High number of sympatric species in the West Atlantic-Caribbean Region
No isotopic evidence of freshwater diets for Miocene cetaceans
Trophic diversity increased: 2nd –4th order consumers
Diversification of modern baleen (Mysticeti) and toothed (Odontoceti) whales
High carbon isotope values indicate these species still favored high productivity waters that were closer to shore than those of extant species