Bivalvia in ancient hydrocarbon seeps

• Bivalves are an important part of the methane seep fauna ever since seeps appeared in the geologic record. The chronostratigraphic ranges of seep-inhabiting chemosymbiotic bivalves show an overall increase in diversity at seeps since the Paleozoic. The most common group at Paleozoic and early Mesozoic seeps are modiomorphids, with a few additional records of solemyids and anomalodesmatans. The most common infaunal chemosymbiotic bivalve taxa at modern seeps, lucinids and thyasirids, appeared at seeps in the Late Jurassic and earliest Cretaceous. They diversified during the Cretaceous synchronous with the peak of the “Mesozoic Marine Revolution” and first occurrences of gastropod predatory drill holes in the shells of seep-inhabiting bivalves, soon after the appearance of these gastropods in the mid-Cretaceous. The two dominant bivalve clades of the modern vent and seep fauna, bathymodiolins and vesicomyids, appeared in the Eocene. Their origin has been linked to a deep-water extinction event at the Paleocene-Eocene Thermal Maximum. However, the fossil record of chemosymbiotic bivalves at seeps during this time interval does not display any extinction. Rather, the mid-Eocene appearance of semi-infaunal and epifaunal bivalves such as bathymodiolins and vesicomyids might be linked to a dramatic rise in seawater sulfate concentrations at this time.

Subject headings

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Geologi (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Geology (hsv//eng)

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Annan geovetenskap och miljövetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Other Earth and Related Environmental Sciences (hsv//eng)

Keyword

Diversity of life

Livets mångfald

The changing Earth

Den föränderliga jorden

Publication and Content Type

ref (subject category)

kap (subject category)