Re: The Maastrichtian of the Spanish Pyrenees (and *Confuciusornis*)

["David Marjanovic" <david.marjanovic@gmx.at>]

> A paper from earlier this year summarizes the Maastrichtian dinosaur
localities of the Pyrenees
> and the collections made that I summarized earlier in several papers of
Spanish publication.
>
>   López-Martínez, N.; Canudo, J.I.; Ardèvol, L.; Pereda Superbiola, X.;
Orue-Etxebarria, X.;
> Cuenca-Bescós, G.; Ruiz-Omeñaca, J.I.; Murelaga, X.; & Feist, M. 2001. New
dinosaur sites
> correlated with Upper Maastrichtian pelagic deposits in the Spanish
Pyerenees: Implications for
> the dinosaur extinction pattern in Europe. _Cretaceous Research_ 22(1):
41-61.

Hey! That's the first time that I have got a paper before it is mentioned
onlist! :-) Unfortunately I haven't got far yet in reading it, so I can't
comment the promising abstract:

"Six new dinosaurs [sic] sites have been found close to the
Cretaceous/Tertiary boundary in Arén (south-central Pyrenees, Huesca, Spain)
in coastal and non-marine deposits of the Arén and Tremp Formations. The
sites contain [...] hadrosaurids, three types of theropod teeth, one
sauropod, at least seven types of eggshells (six ornithoid types and one
Megaloolithidae probably from a sauropod), remains of other vertebrates, and
for charophyte species [important in biostratigraphy]. The fossil-bearing
rocks have been correlated with marine sediments [apparently quite deep sea
sediments are just downdip] containing planktonic foraminifera from the
uppermost Maastrichtian *Abathomphalus mayaroensis* Biozone. These rich and
diversified dinosaur assemblages enable more accurate dating of the faunal
changes that took place during the Maastrichtian in Europe and support the
hypothesis of a sudden dinosaur extinction at the Cretaceous/Tertiary
boundary."

6 different ornithoid shell types suggest lots of coelurosaurs. Maybe the
eggs of *Pyroraptor* and *Gargantuavis* are waiting to be identified...

>From the text:
"Other European dinosaur localities in non-marine rocks previously
considered to be Maastrichtian by authors (e.g. Grigorescu, 1983; Buffetaut
& Le Loeuff, 1991; Buffetaut _et al._, 1997; Gheerbrant _et al._, 1997;
Laurent _et al._, 1999; Garcia _et al._, 1999), need to be recalibrated in
the light of the new chronostratigraphic scale of Gradstein _et al._ (1995)
and refinements in marine-continental biostratigraphic correlation (Riveline
_et al._, 1996). The changes introduced to the duration of the stages has
led to rocks previously assigned to the Early Maastrichtian [...] to be
dated as Late Campanian [...].
    The dinosaur-rich Arén sites, among the youngest in the world, are
crucial for establishing the pattern of the Late Cretaceous dinosaur
succession and extinction in Europe. In particular, they contradict the
hypothesis that dinosaur diversity decreased before their extinction, and
that the extinction was earlier in Europe than in North America (Colombo,
1996; Galbrun, 1997), already challenged by López-Martínez _et al._ (1998)
and Casanovas _et al._ (1999a)."

Sudden death for gradualists >;->

BTW, the fourth author is Xabier Pereda Su_b_erbiola.

While I am at it, I've finally looked at the fossil, and as expected
*Confuciusornis* has a proximally broadened mtIII like *Iberomesornis* and
*Yandangornis*. Unfortunately the beast is in ventral view*, so it's totally
impossible to determine what its pelvis looked like in dorsal view, which
means I still can't add the state "ilia very close together craniodorsally,
so that their dorsal margins are sigmoid and are fused to the neural spines,
but very far apart caudally" to my matrix where it would presently be an
autapomorphy of *Avimimus*.

Does *Confuciusornis* really have only 7 sacral vertebrae? There's room for
a lot more, and some more seem to be there in the poorly preserved region...

* That's not the natural consequence of splitting the plate because the
museum bought the plate unsplit and nearly unprepared (parts of the tail
feathers were prepared, much of the skeleton was covered by a thin layer of
matrix) and prepared the ventral side.