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16
Cor.
Hum.
Uln.
Cpm.
Fern.
Tbt.
Tmt.
• Alopochen aegyptiacus standard
5)c Branta hylobadistes
O Alopochen (M.) kervazoi
+ Alopochen mauritianus
O Alopochen sirabensis
120 -100
I I
80 -60
I
40
I
SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY
-20
I
20 40
I
FIGURE 5.—Ratio-diagram of the mean dimensions of the long bones of Alopochen (Mascarenachen) kervazoi,
compared with those of Alopochen sirabensis, A. mauritianus, and Branta hylobadistes (USNM 322632, see
Olson and James, 1991). The standard is the mean of the dimensions of 11 A. aegyptiacus (USNM 19003,
291415, 346399, 346854, 430829, 431686 431687, 488145, 488713; MNHN-LAC 1874-154, 1911-39). Coracoid
measurement is of internal length; for other bones, measurement is of total length. When measurements are
not known, successive points are united by dashed lines. (Cor.=coracoid, Cpm.=carpometacarpus, Fem.=femur,
Hum.=humerus, Tbt.=tibiotarsus, Tmt.=tarsometatarsus, Uln.=ulna.)
other extinct species of goose, Branta hylobadistes Olson and
James (1991) from the Hawaiian Islands, shows a much more
reduced flying ability, with a considerable shortening of the
carpometacarpus and lengthening of the femur (Olson and
James, 1991). Thus, it can be concluded that A. (M) kervazoi
had only slightly reduced flying ability compared with the continental
form A. aegyptiacus.
The other typical characteristic of A. (M) kervazoi is the
shortening of the bill, with a depth/length ratio larger than in
the continental form A. aegyptiacus. Unfortunately, the bill is
unknown in A. sirabensis (none in MNHN, see also Cowles,
1994) as well as in A. mauritianus. Such shortening is very
conspicuous in the extinct genera from Hawaii, Thambetochen
and Chelychelynechen (Olson and James, 1991). The similarity
of morphology between the species from Reunion and Hawaii
is undoubtedly a convergent adaptation to an insular environment.
Genus Anas Linnaeus
Anas theodori Newton and Gadow, 1893
Sauzier's Teal
FIGURE lq,r
MATERIAL.—Marais de l'Ermitage: Sternum, anterior part,
1895; 1. ulna, 1810; 1. tibiotarsus, 1894.
REMARKS.—Anas theodori was described by Newton and
Gadow (1893) from material including the anterior part of a
sternum, two coracoids, eight humeri, and two tarsometatarsi
from Mauritius. The material preserved in MNHN includes a
cast of this sternum, a coracoid, four humeri, an incomplete juvenile
carpometacarpus, a tibiotarsus, and two juvenile tarsometatarsi.
The anterior part of the sternum from Reunion is
poorly preserved and does not allow detailed comparison. The
Reunion tibiotarsus (Figure Ir), however, is absolutely identi-