Re: Mesozoic snow?

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

Hi Aidan,

<<Ohhh, news to me. Gotta reference for that?>>

But of course.  Yep, the description was Weigert (1995).  My direct source
is actually in English: Guimarota - a Jurassic Ecosystem, Martin T & Krebs
B, 2000, Verlag Dr Friedrich Pfeil, München.  Chapter 12 is by Wichmann MF &
Gloy U, Pterosaurs and urvogels from the Guimarota mine, p.83-86.  I'll hold
up the photo on page 85 so you can have a look.  (I've got it in my attic!)

There are about 100 of these teeth, and the average height is 1.65mm.
That's considerably larger than Archie von Solnhofen.

(Your sieving acquaintance from the fissure fillings might have had a heart
attack at this place.  At the highpoint of the ten year second excavation
campaign, they were mining about a ton of coal a day, and washing 100 kilos
through a series of sieves.  The primary objective was mammals; 10,000
teeth, 1,000 jaws, 20 skulls and 2 partial skeletons from 19 genera.
(That's probably an exaggeration by four or five, as matching up lower and
upper jaws isn't always possible.)

> Zinke, J. (1998): Small theropod teeth from the Upper Jurassic coal mine
of
> Guimarota, Portugal. ­ Paläont. Z. 72, 179­189, 8 Abb., 1 Tab.,

<<Whatever that means>>

Quickly done:

In the years from 1974 until 1976 44o isolated teeth of theropods were
identified from the Upper Jurassic of Guimarots, and 296 could be identified
and measured.  Numerous are teeth from  cf. Compsognathus sp., cf.
Richardoestesia sp., cf. Paronychodon sp., an indeterminate Velociraptorin,
rarer are those from Troodontiden, cf. Dromaeosaurus sp. und von
Tyrannosauriden.  There are also a few in the theropod group of an
indeterminate morphotype.  Most common are the teeth earlier described which
are presumably from Archaeopteryx, accounting for 23,4% of the material.
The most significant result is the evidence of a high diversity of theorpods
that's been found, even if there's uncertainty with some of the
identifications.
Cheers
Trevor

The excavations of Guimarota, Upper Jurassic of Portugal by Self MY (ie. me)
http://www.geocities.com/trevor_dykes/guimarotaexcavations.htm
The Mesozoic - more than just the dinosaur