Geoscience Reference
In-Depth Information
labyrinthodont,
Metoposaurus
and also the
related, but smaller,
Latiscopus
. Mammal-like
reptiles are only known from
fragmentar y specimens of the cynodont,
Pachygenelus
, from Garza County in Texas,
but other nonarchosaurian reptiles are
more diverse and include procolophonids,
as in Chinle, and also rhynchosaurs and
trilophosaurs. The archosaurs include a
number of aetosaurs, rauisuchids, and
phytosaurs, exactly as in the Chinle.
Regarding dinosaurs, the only
saurischian remains positively identified
from the Dockum Group are those of a
procompsognathid from Quay County, New
Mexico. Several fragmentary specimens
have been referred to
Coelophysis
, but
none can be positively identified, and the
dinosaurian affinities of
Spinosuchus
remain in doubt. Ornithischians belonging
to the fabrosaurids have been described
from Garza County, which, if the supposed
Carnian age for this locality is correct, would
be among the oldest ornithischians in the
world (Murray, 1986).
The Dockum flora also correlates at
specific level with that of the Chinle
Group. Ash (1972) recorded at least eight
species common to both units, including
Araucarioxylon arizonicum
, and
concluded that the Dockum flora is more
closely related to the Chinle than to any
other.
F
URTHER
R
EADING
Ash, S. R. 1972. Plant megafossils of
the Chinle Formation.
Museum
of North Arizona Bulletin
47
, 23-43.
Camp, C. L. 1930. A study of the
phytosaurs, with descriptions of new
material from western North America.
Memoirs of the University of
California
10
, 1-174.
Camp, C. L. and Welles, S. P. 1956.
Triassic dicynodont reptiles. I. The
North American genus
Placerias.
Memoirs of the University of
California
13
, 255-348.
Colbert, E. H. 1947. Little dinosaurs of
Ghost Ranch.
Natural History
56
,
392-399, 427-428.
Colbert, E. H. 1964. The Triassic dinosaur
genera
Podokesaurus
and
Coelophysis
.
American Museum
Novitates
2168
, 1-12.
Cope, E. D. 1887a. The dinosaurian
genus
Coelurus
.
American Naturalist
21
, 67-369.
Cope, E. D. 1887b. A contribution to the
history of the Vertebrata of the Trias
of North America.
Proceedings of the
American Philosophical Society
24
,
209-228.
Fiorillo, A. R., Padian, K. and
Musikasinthorn, C. 2000.
Taphonomy and depositional
setting of the Placerias Quarry (Chinle
Formation: Late Triassic, Arizona).
Palaios
15
, 373-386.
Foster, J. R. 2002. Vertebrate track sites
in the Chinle Formation (Late Triassic)
of the Circle Cliffs area, southern
Fraser, N. C., Irmis, R. B. and Elliott, D. K.
2005. A procolophonid (Parareptilia)
from the Owl Rock Member, Chinle
Formation of Utah, USA.
Palaeontologia Electronica
8
, 1-7.
Gregory, H. E. 1917. Geology of the
Navajo country.
United States
Geoological Survey Professional Paper
93
.
Hasiotis, S. T. 2005. Crayfish fossils and
burrows from the Upper Triassic
Chinle Formation, Canyonlands
National Park, Utah.
http://
Search WWH ::
Custom Search