Page 316 - Introduction to Paleobiology and The Fossil Record

SPIRALIANS 1: LOPHOPHORATES 303

PALEOZOIC MESOZOIC CENOZOIC
Camb Ord Sil Dev Carb Perm Tr Jur Cret

Acrotretida
Lingulida

Siphonotretida
Paterinida
Craniida

Craniopsida
Trimerellida
? ? ? ? Phoronida ?
Obolellida
Naukatida
Chileida
Dictyonellida
Kutorginida
Billingsellida
Orthotetida
Strophomenida
Productida
?
Protorthida
Orthida
Pentamerida
Rhynchonellida

Atrypida
Terebratulida
Athyridida
Thecideida
? ?
Spiriferida
Spiriferinida

Figure 12.2 Classification and stratigraphic distribution of the Brachiopoda. (Courtesy of Sandra
Carlson.)

at the time of deposition. The ratio of isotopes provided many new data on the termination
within the crystal lattice of the brachiopod of the Caledonian Orogeny (decrease in the
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shell was often controlled by the provenance 87 Sr/ Sr ratio due to limited infl ux of fresh-
of the chemical elements (marine or terres- water), uplift during the Variscan Orogeny
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87
trial) and temperature and salinity of the sea- (increase in Sr/ Sr ratio due to increased
water. Carbon, oxygen and strontium isotopes influx of freshwater) and Devonian climate

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are particularly useful. Devonian brachiopod warming (negative δ O excursions) together
shells from North America, Spain, Morocco, with increased rates of carbon burial signaled
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Siberia, China and Germany analyzed for by positive δ C excursions (van Geldern
87
86
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stable isotopes (δ C, δ O and Sr/ Sr) have et al. 2006).