Other Cool Stuff

Cretaceous Thermal Maximum ~85-90 Ma

The Cretaceous Thermal Maximum is the warmest period in Earth's history in the last ~200 million years. Sea surface temperature data (from geochemical studies of planktic foraminifera and organic biomarkers) suggest that tropical temperatures exceeded 35°C.

Deep Sea Sediments and Microfossils

As a professional fossil watcher, it is a particular delight to explore deep sea mud--the stuff is literally made out of fossils!  Of course, they are rather small (a few microns to a few millimeters), but there is lots of life's diversity there.  Some deep sea sediments are composed mainly of siliceous fossils--made of opal--such as diatoms and radiolarians.  Others are made of carbonate such as the foraminifera and coccolithiphorids.

Fish and Hypoxia

One of the predictions for the future is that parts of the ocean are expected to develop extensive low oxygen (hypoxic) zones. One worry is that larger low oxygen areas may affect fish, lowering catches and depriving people of rich fisheries. I looked at this question by studying past hypoxic periods in the Mediterranean, when the basin repeatedly became a Black Sea-like basin  where, today, the ocean deeper than ~30 m is almost completely anoxic.

Fossils as indicators of Ancient life

Although lots of things don't preserve well as fossils, it turns out that we can reconstruct most parts of ecosystems pretty well.  The terrestrial plant record is well preserved as pollen grains.  The base of food chains has a good record in calcareous algae and diatoms.  Fossil zooplankton (that eat the algae or other protists) are represented by the foraminifera and ostracodes as well as many other microfossils.  And fish have an amazing, but mostly unstudied record of fish teeth and shark scales.

The Cretaceous-Paleogene Boundary in Denmark

This is a neat idea--slather large amounts of resin on the outcrop at Stven's Klint, in Denmark and then pull of the resulting 'peel' to make a sample of the Cretaceous-Paleogene boundary section. In this slab (taken by folks at Bremen University), the Cretaceous is the lower white chalk below the rusty orange bed, the K/Pg boundary is the orange bed and the basal Paleogene starts with the greenish clay beds that gradually shift back into white Paleogene chalk.Those are the tips of our boots for scale.