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Why sauropods laid small eggs and other news

Ben Creisler

I tried sending this item two hours ago and it did not get through it
appears. So here is a slightly revised version. These are a number of
recent news and blog items. I'll see what happens...

Why sauropods laid small eggs (news release)


(The paper was posted on the DML back in May:

http://dml.cmnh.org/2014May/msg00042.html )

Could  dinosaurs roar?


Baby ichthyosaur fossil found in Australia (radio interview)



Past Time podcast about baby Parasaurolophus "Joe" and other baby dinosaurs
Episode 12 Field Guide: Growing up Dinosaur! Interview Dr. Andy Farke.

Intro material



Magnetic field flips and oxygen loss during mass extinctions


Paper is now in open access:

Yong Wei, Zuyin Pu, Qiugang Zong, Weixing Wan, Zhipeng Ren, Markus
Fraenz, Eduard Dubinin, Feng Tian, Quanqi Shi, Suiyan Fu, Minghua Hong
Oxygen escape from the Earth during geomagnetic reversals:
Implications to mass extinction.
Earth and Planetary Science Letters 394: 94–98
DOI: 10.1016/j.epsl.2014.03.018

Geomagnetic field reversal substantially weakens the protection for
the atmosphere.
Solar wind energizes more oxygen ions to escape when geomagnetic field
is weakened.
Oxygen escape may explain the drop of atmospheric level during mass extinction.
The causal relation between reversal and mass extinction should be
The simulated oxygen escape rate based on knowledge of Mars support
our hypothesis.

The evolution of life is affected by variations of atmospheric oxygen
level and geomagnetic field intensity. Oxygen can escape into
interplanetary space as ions after gaining momentum from solar wind,
but Earth's strong dipole field reduces the momentum transfer
efficiency and the ion outflow rate, except for the time of
geomagnetic polarity reversals when the field is significantly
weakened in strength and becomes Mars-like in morphology. The newest
databases available for the Phanerozoic era illustrate that the
reversal rate increased and the atmospheric oxygen level decreased
when the marine diversity showed a gradual pattern of mass extinctions
lasting millions of years. We propose that accumulated oxygen escape
during an interval of increased reversal rate could have led to the
catastrophic drop of oxygen level, which is known to be a cause of
mass extinction. We simulated the oxygen ion escape rate for the
Triassic–Jurassic event, using a modified Martian ion escape model
with an input of quiet solar wind inferred from Sun-like stars. The
results show that geomagnetic reversal could enhance the oxygen escape
rate by 3–4 orders only if the magnetic field was extremely weak, even
without consideration of space weather effects. This suggests that our
hypothesis could be a possible explanation of a correlation between
geomagnetic reversals and mass extinction. Therefore, if this causal
relation indeed exists, it should be a “many-to-one” scenario rather
the previously considered “one-to-one”, and planetary magnetic field
should be much more important than previously thought for planetary