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Cimolopteryx sp. (Aves, Charadriiformes) from the Frenchman Formation (Maastrichtian), Saskatchewan

Authors:

Abstract

Cimolopteryx sp. (Aves, Charadriiformes) is reported from the Frenchman Formation (late Maastrichtian) of Saskatchewan, providing the first record of a latest Cretaceous bird from nonmarine sediments of western Canada.
I
NOTES
2729
I
STEVENSON, R. K., and MARTIN, R.
E
1988.
Amazonitic K-feldspar isotope geochronology of the Portman Lake area, Northwest Terri-
I
in granodiorite at Portman Lake, Northwest Territories: indica- tories. Canadian Journal of Earth Sciences,
24:
2188-2196.
tions of low f(O,), low f(S,) and rapid uplift. The Canadian YORK,
D.
1969.
Least squares fitting of a straight line with correlated
Mineralogist,
26:
1037
-
1048.
errors. Earth and Planetary Science Letters,
5:
320-324.
STEVENSON, R.
K.,
CUMMING,
G.
L.,
and KRSTIC, D.
1987.
Lead-
Cimolopteryx
sp. (Aves, Charadriiformes) from the Frenchman Formation
(Maastrichtian), Saskatchewan
TIM
T.
TOKARYK AND PAUL C. JAMES
Saskatchewan Museum
of
Natural History,
2340
Albert St., Regina, Sask., Canada S4P
3V7
Received April
27, 1989
Revision accepted July
19, 1989
Cimolopteryx
sp. (Aves, Charadriiformes) is reported from the Frenchman Formation (late Maastrichtian) of Saskatchewan,
providing the first record of a latest Cretaceous bird from nonrnarine sediments of western Canada.
Cimolopteryn
sp. (Aves, Charadriiformes) est
le
premier oiseau fossile du Cr6tacB tardif dans les sediments marins de l'ouest
du Canada, soit dans la Formation de Frenchman (Maastrichtien tardin.
I
[Traduit par la revue]
I
Can.
J.
Earth
Sci.
26,
2729-2730 (1989)
I
Introduction
Little is known about Cretaceous birds from western
Canada.
Caenagnathus collinsi
Sternberg (1940) and
Caena-
gnathus stembergi
Cracraft (197 1) from the Judith River For-
mation (Carnpanian) of Alberta were originally described as
I
birds but are now considered saurischian dinosaurs (Osmolska
1971). Bardack (1968) recorded
Hesperomis regalis
from the
1
marine Pierre Shale (early Carnpanian) of Manitoba, and
Martin and Stewart (1982) described an ichthyornithiform
from the same formation. Fox (1974) tentatively referred
specimens from the nonrnarine Foremost Formation (middle
Campanian) to
Hesperomis
cf.
H.
regalis
and reported
Ichthyomis
sp. from the Vimy Member of the marine
Kaskapau Formation (Fox 1984).
In view of the fact that no Maastrichtian birds have hitherto
been discovered in nonrnarine sediments of western Canada,
we report here the first specimen of
Cimolopteiyx
from the
Frenchman Formation (Maastrichtian) of Saskatchewan.
I
ABBREVIATIONS: Saskatchewan Museum of Natural History
Paleontological Collection (SMNH P); University of Califor-
I
nia Museum of Paleontology (UCMP); Yale Peabody Museum
(Y
PM) .
Systematic paleontology
CLASS
Aves
ORDER
Charadriiformes
FAMILY
Cirnolopterygidae
Cimolopteiyx
sp.
(Fig. 1; Table
1)
Referred specimen
SMNH P1927.936, humeral end of left coracoid.
Printed
in
Canada
/
Imprim6
au
Canada
Locality and geology
SMNH locality 72F08-0012 ("Gryde locality"), French-
man Formation (Maastrichtian), Frenchman Valley, south of
Shaunavon, Saskatchewan.
Our attention was originally drawn to this site in 1984 by
scattered ceratopsian skull fragments (probably
Triceratops)
and mammalian teeth. Bones are found within the top 50 cm of
a 2 m thick dark gray siltstone. The locality is considered as
being in the Frenchman Formation, as indicated by the typi-
cally Lancian mammalian assemblage (J. Storer, personal
communication, 1988). The Cretaceous
-
Tertiary (K
-
T)
boundary site reported by Lerbekrno (1987, and references
therein) is across the valley from the Gryde locality and is
stratigraphically higher.
Measurements
See Table 1.
Description
The bicipital attachment appears as a small, distinct apex
and forms a medial ridge sloping distally on both sides. The
coracohumeral surface is 2.8
rnm
long and deflects from the
glenoid facet to the head at about 40". The glenoid facet shows
a shallow basin, and the external ridge is weak. The internal
basin beside the ridge of the glenoid facet is very shallow.
There is very little evidence of a longitudinal basin on the
ventral side. The distal edge of the scapular facet is placed high
alongside the glenoid facet. The proximal edge of the scapular
facet is less defined than the distal edge, giving the appearance
of a proximally tilted cup. The facet itself is a deep basin. The
procoracoid is missing. The procoracoid foramen is distal to
the scapular facet and i$ closer to the outer edge of the shaft.
Discussion
Among the five previously recognized species of cimolo-
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CAN.
J.
EARTH
SCI.
VOL.
26,1989
FIG.
1.
(a)
Dorsal view and
(b)
internal view of the left coracoid
(SMNH
P1927.936)
of
Cimolopteiyx
sp. from the Frenchman Forma-
tion, Saskatchewan. Scale bar. represents
5
rnm.
TABLE
1.
Measurements of coracoids of Cimoloptelygidae (revised
from Brodkorb
1963)
Measurements
(rnm)*
Species and
catalog No.
ABCDEFG
Cimolopteryx minima
UCMP
53976 1.5 1.6 3.0 1.8 0.8 2.1 2.9
Cimolopteiyx rara
YPM
1805 2.0 2.3 5.5 3.2 1.3 2.6
-
UCMP
53963 2.0 2.3 5.4 3.3 1.7 2.8 4.3
UCMP
53962 2.0 2.2 4.6 3.0 1.5 2.6
-
Cimolopteryx
sp.
SMNH
P1927.936 2.3 2.6 4.7 3.2 1.6 2.6 4.0
Cimolopteryx maxima
UCMP
53973 3.7 3.7 8.7 4.7 2.6
-
-
UCMP
53957 3.7 4.2 8.9 5.0
-
-
-
Ceramomis major
UCMP
53959 3.0 3.2 7.9 4.4 1.8
-
6.0
Palintropus retusus
YPM
513 2.6 2.5 6.4 4.2
-
4.0 3.9
*
A,
length of scapular facet;
B,
width of scapular facet;
C,
length of
glenoid facet;
D,
width of glenoid facet;
E,
distance from scapular facet to
procoracoid foramen;
F,
least width of shaft;
G,
width below brachial tuber-
osity.
pterygids
-
Cimolopteryx rara, Cimolopteryx minima, Cimo-
lopteryx maxima, Ceramomis major,
and
Palintropus retusus
-
SMNH P1927.936 shows closest affinities to
Cimolopteryx,
specifically
C. rara
(see Table 1).
Palintropus retusus
and
C. major
have larger scapular facets. In
P.
retusus,
the scapu-
lar facet of the coracoid is smaller in width than length, which
is incompatible with SMNH P1927.936 and not typical of any
other cimolopterygids. The glenoid facet in
P. retusus
and
C. major
is likewise much longer than in the Saskatchewan
specimen.
The greatest similarity of SMNH P1927.936 is to
C.
rara
(Brodkorb 1963, Fig.
4).
Although the scapular facet is
slightly larger in the Saskatchewan specimen, the size of the
glenoid facet, the length between the scapular facet and the
procoracoid foramen, and the least width of the shaft suggest
that SMNH P1927.936 may be referable to
C. rara.
The furcu-
lar facet on the Saskatchewan specimen is well preserved but
poorly developed. If the referred specimen of
C. rara
(Brodkorb 1963, Fig.
4)
is excluded, this feature is not pre-
served on other cimolopterygids.
The presence of
Cimolopteryx
in the Frenchman Formation
extends the geographic range northward, albeit by only a few
hundred kilometres. In light of the relatively recent debate on
the K-T extinctions and the comparatively poor avian record
in the Late Cretaceous, especially in western Canada, this
specimen not only adds to the fauna of the Frenchman Forma-
tion but also may augment future discussion on the avian
record of extinction at this critical boundary.
Acknowledgments
We have benefitted greatly from discussions with or reviews
by John Storer (Regina, Saskatchewan), Lany Martin (Law-
rence, Kansas), Storrs Olson (Washington, DC), Clive Coy
(Drumheller, Alberta), and one anonymous referee. The senior
author wishes to thank Larry Martin for his hospitality during a
visit to the University of Kansas. We also thank Darren Tanke
(Drumheller, Alberta) for the discovery of the specimen in our
collections. Funding was provided by the Saskatchewan
Museums Association and the Museum Associates of the
Saskatchewan Museum of Natural History. Gwyn Langemann
(Regina, Saskatchewan) made the illustrations in Fig. 1.
BARDACK,
D.
1968.
Fossil vertebrates from the Marine Cretaceous of
Manitoba. Canadian Journal of Earth Sciences,
5:
145- 153.
BRODKORB,
P.
1963.
Birds from the Upper Cretaceous of Wyoming.
Proceedings,
13th
International Ornithology Congress, pp.
55 -70.
CRACRAFT,
J.
1971.
Caenagnathiformes: Cretaceous birds convergent
in jaw mechanisms to dycynodont reptiles. Journal of Paleontol-
ogy,
45:
805
-
809.
Fox,
R.
C.
1974.
A middle Campanian, nonrnarine occurrence of the
Cretaceous toothed bird
Hesperomis
Marsh. Canadian Journal of
Earth Sciences,
11:
1335
-
1338.
1984.
Zchthyomis
(Aves) from the early Turonian (Late Cre-
taceous) of Alberta. Canadian Journal of Earth Sciences,
21:
258-260.
LERBEKMO,
J. F.
1987.
Magnetostratigraphic restrictions on the age
of the Frenchman Formation and the magnitude of the sub-
Frenchman disconformity in southwest Saskatchewan. Bulletin of
Canadian Petroleum Geology,
35:
454 -459.
MARTIN,
L. D., and
STEWART,
J. D.
1982.
An ichthyornithiform bird
from the Carnpanian of Canada. Canadian Journal of Earth
Sciences,
19:
324
-
327.
OSMOLSKA,
H.
1976.
New light on the skull anatomy and systematic
position of oviraptor. Nature (London),
262:
683-684.
STERNBERG,
R.
M.
1940.
A toothless bird from the Cretaceous of
Alberta. Journal of Paleontology,
14:
81
-
85.
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For personal use only.
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Oviraptor philoceratops Osborn, 1924—a plunderer allegedly fond of ceratopsian eggs—is an Upper Cretaceous vertebrate assigned to the theropod dinosaurs1. The holotype, comprising a compressed skull with mandibles, several cervical vertebrae, fragmentary shoulder girdle and forelimbs, was found in the Djadokhta Formation (? Santonian), Gobi Desert, Mongolia. For many years this was the only specimen known and its poor preservation showed only that Oviraptor was a toothless bipedal animal, with a lightly built skull, unusually short and deep. The lack of teeth and the structure of the manus were the main arguments for assigning it to the family Ornithomimidae1,2.
Caenagnathiformes: Cretaceous birds convergent in jaw mechanisms to dycynodont reptiles
  • J Cracraft
CRACRAFT, J. 1971. Caenagnathiformes: Cretaceous birds convergent in jaw mechanisms to dycynodont reptiles. Journal of Paleontology, 45: 805 -809.
Downloaded from www.nrcresearchpress.com by McMaster University on 12
  • Can J Earth
  • Sci
Can. J. Earth Sci. Downloaded from www.nrcresearchpress.com by McMaster University on 12/10/13 For personal use only.
New light on the skull anatomy and systematic position of oviraptor
OSMOLSKA, H. 1976. New light on the skull anatomy and systematic position of oviraptor. Nature (London), 262: 683-684.