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Yet more new references arrived the library, some
of them previosly mentioned on the list.
First of all, a large paper by Galton, reported by
Tracy last month.
Galton,
P. 2000, Are Spondylosoma and Staurikosaurus (Santa Maria Formation,
Middle-Upper Triassic, Brasil) the oldest saurischian dinosaurs?
Palaontologische Zeitschrift, v.74, n. 3, p. 393-423.
I notice
that Spondylosoma is still classified as a possible dinosaur on many websites,
such as the Dinosauricon and Dinodata. Galton provides good evidence in a
comprehensive description, that the genus is actually a
rausuchid.
Spondylosoma
is actually from the Therapsid Assemblage Zone of the Santa Maria Formation,
which would make it Ladinian (Middle Triassic) in
age.
Lectotype-
(GPIT 479/30) fourth or fifth cervical vertebra, sixth or seventh cervical
vertebra, posterior dorsal vertebra, first sacral vertebra, second sacral
vertebra
Paralectotypes-
(GPIT 479/30) mid dorsal centrum*, third sacral vertebra*, proximal and distal
scapula, proximal humerus, proximal pubis, distal
femur
* these
are from a specimen smaller than the holotype
(GPIT
479/0253a) tooth
Referred-
tooth, first dorsal vertebra
Material
incorrectly referred- (GPIT 479/0249) distal caudal
vertebra
This was
described as an anterior dorsal of Spondylosoma, but is really a distal caudal
of an undetermined archosaur.
(GPIT
479/0256a) proximal radius
This was
described as a distal radius of Spondylosoma, but is really a proximal radius of
an undetermined archosaur.
Relationships-
Spondylosoma
lacks the dinosauriform synapomorphy of having the cervical column follow a
strong sigmoid curve, as the central faces are only slightly offset. It
does have an elongate pubis like Pseudolagosuchus and dinosaurs, but so do
poposaurids and chatterjeeids. It lacks the cervical epipophyses and
distally projected deltopectoral crest of dinosaurs, but does have more than two
sacrals. Galton writes much regarding sacral number in dinosaurs and
concludes only two sacrals were present in dinosaurs primitively. Some
specimens of Sellosaurus have two sacrals, while others have three. Some
prosauropods have a third sacral originating from the last dorsal, others from
the first caudal. It's all very complex, but in any case rausuchids,
poposaurids, ornithosuchids and chaterjeeids have three sacrals as well.
Finally, Spondylosoma has hyposphene-hypantrum articulations like saurischians,
but these are also found in rausuchids and prestosuchids. Galton concludes
Spondylosoma is a rausuchian and probably a rausuchid, based on sacral vertebral
characters not seen in poposaurids.
Now get
it off your lists people ;-)
On a
related note, Peter Buchholz pointed out to me that the tooth of
"Beelemodon" (http://www.cmnh.org/fun/dinosaur-archive/2001Feb/msg00005.html)
has a wear facet. I believe that such a structure would only be expected
if there were teeth in the other jaw wearing against it. As ornithischians
have toothless predentaries opposing their premaxillary teeth, this might be
final proof "Beelemodon" is a theropod and not an ornithischian.
Therefore, I suggest with more confindence that "Beelemodon" be placed as
Coelurosauria indet.
A paper
I haven't seen mentioned on the list-
Lopez-Martinez,
Canudo, Ardevol, Suberbiola, Orue-Etxebarria, Cuenca-Bescos, Ruiz-Omenaca,
Murelaga and Feist, 2001. New dinosaur sitescorrelated with Upper Maastrichtian
pelagic deposits in the Spanish Pyrenees: Implications for the dinosaur
extinction pattern in Europe. Cretaceous Research, 22(1)
41-62.
Several
dinosaurs have been found in the Late Maastrichtian Lower Tremp Formation of
Spain.
-
"Velociraptorinae"
Teeth
with larger posterior than anterior serrations (3 per mm vs. 5 per mm) and
inclined distal serrations. (ex. MPZ 98/72)
-
"Dromaeosaurinae"
Teeth
with only distal serrations, which are not inclined (6-16 per
mm).
-
Euronychodon sp.
Recurved
teeth lacking serrations, but having a lingual vertical crest. (ex. MPZ 98/76,
98/77)
-
Coelurosauria indet.
Teeth
similar to Euronychodon sp., but lacking the vertical crest. (ex. MPZ
98/82)
-
Sauropoda indet.
Single
tooth found with eggshells.
-
Euhadrosauria incertae sedis
(BLA-99)
partial maxilla, jugal, dentary, surangular, teeth
There is
no surangular foramen, like hadrosaurs except Protohadros. Features more
derived than Telmatosaurus include- coronoid process inclined rostrally, single
median carina on dentary teeth, complete absence of secondary ridges on
crowns. Other characters differing from Telmatosaurus are- jugal
is shorter and more expanded rostrally, narrower dentary teeth not recurved
distally. The shallow caudal jugal process with scalloped ventral margin
resembles brachylophosaurs, while the flat dorsoventrally expanded rostral jugal
process and high postorbital jugal process resemble lambeosaurines, especially
Hypacrosaurus. The less prominent mandibular diastema distinguishes it
from Pararhabdodon.
-
Euhadrosauria indet.
(~6 m)
cervicals, dorsals, dorsal ribs, caudals, chevrons, humerus, proximal ulna,
femur (730 mm), distal tibia, metatarsal III, phalanx
The
caudals have tall, caudally angled neural spines like Pararhabdodon, but unlike
Telmatosaurus, while the humerus is
hadrosaurine-like.
Mickey
Mortimer
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