June 8. Brachiopods

Just a short one today, to mention the brachiopods again. 

Two of the major groups of brachiopods, the productids or spiny brachiopods, and the sprifers, with elongate, wing-like shells, continued to thrive during the Mississippian.

Productus longispinus (left); Spirifer glaber (right)

In 2008 a report by Chinese and Polish paleontologists described an unusual assemblage of silicified brachiopods, including 4 new species, from the Muhua area of southern China. LINK

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Laki Eruption

Beginning on June 8, 1783, and continuing for eight months, a fissure – a crack in the earth – and 130 eruptive vents began to pour basaltic lava over southern Iceland at Lakagigar, often called Laki. By most estimates the volume of erupted material, more than 14 cubic kilometers, is the greatest on record during historic times. The lava was accompanied by poisonous fumes composed of hydrofluoric acid and sulfur dioxide which killed half of all the livestock in Iceland and devastated the countryside well beyond the lava flows themselves. The resulting famine killed an estimated 25% of Iceland’s human population. Worldwide, the ash and acid aerosols in the atmosphere caused dramatic climatic effects – crop failures in Europe, droughts in India, extremely low flows in the river Nile, and a North American winter cold enough for the Mississippi River to freeze over at New Orleans. The sulfurous fumes were strong enough in France to kill a few dozen people, and the U.S. ambassador to France, Benjamin Franklin, speculated on the connections between the poisonous fogs in Europe and the Icelandic eruption – correctly, as it turned out. The total death toll worldwide from this eruption may have been as high as 6 million when all the impacts of the famines are included.

There’s a new book out on the Laki eruption, just published in March 2014. Island on Fire is by Alexandra Witze, an award-winning science journalist. I haven’t finished it yet, what I have read is an excellent report on the eruption and its worldwide consequences.

—Richard I. Gibson

Brachiopod drawing from an old textbook (public domain)