Re: Liaoning Preservation

[K and T Dykes <ktdykes@arcor.de>]

<<Regarding the remarkable & numerous specimens of "bird-like" avian &
non-avian dinosaurs of ca 130 mya(are most or all from this time), can it be
concluded by the deposits they were found in what killed them?>>

I follow the remarkable mammals more than dinos, Amtoine.  Nevertheless, I
might be able to help a bit.  The mammals come from two distinct faunas.
Most (six genera and six species) are around 125 million years old, and
that's supported by a radiometric dating.  The exceptions are the
Repenomamus sisters and Gobiconodon zofiae.  They're from lower in the
Yixian Formation, and somewhere between 128 - 139 million years, (Hu, Meng,
Wang & Li (2005), Large Mesozoic mammals fed on young dinosaurs, Nature,
433, p.149-152).  The dinos are also split into two faunas but I don't know
the details.

As for cause of death, I'm sure it must have varied.  The baby
Psittacosaurus in the stomach area of Repenomamus robustus may have
committed suicide first, or have been killed by a mammal.  The happy eater
(R. giganticus) was found in a peaceful pose.  Natural eco-terrorism via a
volcanic gas attack is possible.
Cheers
Trevor

Mesozoic Eucynodonts - The Yixian Formation
http://home.arcor.de/ktdykes/symmetro.htm#yixian
The Mesozoic - more than just the dinosaur.