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Post by another specialist on Jul 22, 2006 7:19:38 GMT
SYSTEMATIC PALEONTOLOGY Order PASSERIFORMES Family CORVIDAE Genus Corvus Linnaeus, 1758 Two new species of crows in lowland fossil sites on Oahu and Molokai (Olson
and James 1982a, b, 1984) are known from associated fossil skeletons preserved
so well as to rival the best skeletal preparations in modern museum collections.
These fossils were collected under water in a flooded cavern near Barbers Point,
Oahu. We have designated specimens from this cavern as the holotypes for both
of the new species, although one of the species is known so far from Oahu only
from the holotype, and occurs far more abundantly in the dune sites on Molokai.
Bones of crows have also been found in lava tubes on Maui (James et al. 1987)
12 ORNITHOLOGICAL MONOGRAPHS NO. 46
and Hawaii. These are all isolated elements or fragmentary skeletons that need
further study before they can be identified to species with reasonable assurance.
We compared the new Hawaiian crows to all other species of Corvus that occur
in the Pacific Basin and peripheral continental areas, except two geographically
restricted species for which specimens were not available.
To simplify our diagnoses, we can eliminate the following species from further
discussion. The new Hawaiian crows are markedly larger than Corvus dauuricus,
C. moneduloides, C. enca, C. typicus, C. kubaryi (bill also narrower), C. frugilegus,
C. brachyrhynchos, C. caurinus, C. imparatus, C. orru, C. torquatus (bill also less
deep), or C. cryptoleucus. The bills of the new species are deeper than in C.
coronoides, C. mellori, C. torquatus, or C. validus. Compared to the new species,
Corvus corone has the ventral surface of the maxilla less excavated, the nostril
longer, and the bill less deep; C. bennetti has a smaller bill; and C. tristis has the
mandible less deep and the sternum relatively large in proportion to humerus
length.
Comparative material examined: The complete skeleton of Corvus hawaiiensis
that we used in our comparisons, USNM 501638, is from an atypically small
male bird. We supplemented this specimen by vemoving the skull, mandible, and
several long bones from the skin of a large male ofC. hawaiiensis, USNM 177993.
Specimens of C. fiorensis (restricted to Flores in the Lesser Sundas) and C. fuscicapillus
(restricted to parts of New Guinea and its satellites) were not available
for comparison. Skeletal material from the Smithsonian collections included: C.
dauuricus male, 292083; females, 292082, 319401. C. moneduloides male, 561635;
female, 561634. C. enca male, 225830; unsexed, 224802. C. typicus male, 226205
(trunk only). C. kubaryi unsexed, 613280. C. validus males, 557299, 557300,
558297; females, 489028, 557301. C. tristis female, 489028. C. frugilegus males,
290314, 291673. C. brachyrhynchos male, 554206; female, 499510. C. caurinus
males, 561899, 612996; females, 612993, 612995. C. corone male, 500773; unsexed,
289948. C. macrorhynchos males, 290456, 292081, 500768; females,
290955, 500774; unsexed, 318366. C. orru male, 559044, females, 558338, 559045.
C. torquatus males, 289947, 291412, 292078; female, 292858. C. cryptoleucus
males, 553971, 553972, 553973, 555254; females, 498679, 554139. C. corax
males, 489704, 499938; female, 555261; unsexed, 18622, 290441. Of C. moriorum,
we examined the following subfossil specimens: NMNZ S 962, skull and
partial skeleton; AU 6120, partial postcranial skeleton; AU 6121.16, mandible;
CMC AV3310, skull and partial skeleton. We also made comparisons with study
skins of the following species in the Smithsonian collections: C. hawaiiensis (12
specimens), C. woodfordi, C. meeki, C. imparatus, C. bennettL C. coronoides, and
C. mellori. |
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Post by another specialist on Jul 22, 2006 7:25:12 GMT
Corvus impluvlatus, new species
(Figs. 3B, 4B, 5B, 6B, 7B, 8B, E)
"Corvus, deep-billed" Olson and James, 1982b:38, 44; 1984:771.
Holotype: Nearly complete skeleton, BBM-X 153652. Collected 22 July 1977
by Storrs L. Olson, Helen F. James, Aki Sinoto and others, with the aid of SCUBA
gear. The specimen includes the cranium with the maxilla, palatines, and jugals
in place (Figs. 3B, 4B, 5B), both pterygoids, both quadrates, the left prefrontal,
the mandible (Figs. 3B, 6B), twelve tracheal rings, the syringeal drum, the furcula,
the sternum, ten complete ribs plus some fragments, ten cervical vertebrae (the
complete cervical series except for the fourth vertebra), three caudal vertebrae,
all of the long bones of the pectoral skeleton (scapulae, coracoids, humeri (Fig.
7B), ulnae, radii, carpometacarpi), the radiale, ulnare, and one alar phalanx from
the right side, the left femur (Fig. 8B), both tibiotarsi and fibulae, the right tarsometatarsus
(Fig. 8E), and twelve pedal phalanges.
Type locality: Flooded cavern, Site 50-Oa-B6-139, Barbers Point, Oahu, Hawaiian
Islands.
Distribution: Oahu: Barbers Point.
Etymology: An adjective formed from Latin, impluvium, n., the skylight in the
roof of the atrium of a Roman house, in reference to the nature of the type locality,
which we entered by leaping through a skylight into the clear water below. The
root word pluvius, meaning rainy, may be taken as a further allusion to the watery
environment of the cavern.
Measurements (ram) ofholotype: Maxilla: dorsal length, 66.8; length from anterior
rim of narial opening, 40.2; maximum width, 26.7; width of nasofrontal
hinge, 23.8; maximum height, 21.4; height through lateral nasal bar, 24.1; length
of narial opening, 13.7; height of narial opening, 8.5. Cranium: total length with
maxilla, 105.1; length from supraoccipital to nasofrontal hinge, 45.4; length from
nasofrontal hinge to bill tip, 66.7; orbit length (ectethmoid to postorbital process),
26.2; width of frontal between orbit rims, 25.6; width behind postorbital processes,
42.9; height from basitemporal plate to sloall roof, 31.7; length ofbasitemporal
plate (anterior margin of basitemporal plate to posterior extremity of occipital
condyle), 15.7; width between external rims of the articular faces for the
quadrates, 39.9. Mandible: total length, 87.3; length of tomial crest, 52.8; symphysis
length, 22.2; greatest width of mandible, 45.0; width of articular end with
medial process, 16.9; height at angle of mandible, 15.5; greatest height of subrhamphothecal
ramus, 13.8. Scapula: length, 57.2; proximal width, 14.2. Sternum:
length through manubrial spine, 62.1; width below costal facets, 32.2; length of
carina, 60.5; depth of carina, 18.6. Coracoid: length, 51.2; width of sternal end,
13.2. Humerus: length, 78.5; proximal width, 21.2; length of deltoid crest, 24.3;
mid-shaft width, 6.9; distal width, 17.1. Ulna: proximal width, 11.8; distal width,
11.2. Radius: length, 85.9. Carpometacarpus: length, 55.6; proximal depth, 12.9;
distal depth, 12.0. Pelvis: xvidth across trochanters, 40.5. Femur: length, 63.1;
proximal width, 13.7; mid-shaft depth, 4.6; distal width, 13.2. Tibiotarsus: length
without cnemial crest, 105.4; proximal width, 32.9; length of fibular crest, 17.8;
distal width, 11.4. Tarsometatarsus: length, 72.2; proximal width, 12.7; mid-shaft
width, 4.6; depth of third trochlea, 5.2. For additional measurements, see
Table 1.
Paratypes: Partial skeleton, USNM 386431, including the cranium (with maxilla,
palatines, and jugals attached), the right pterygoid, the left quadrate, the
mandible, the furcula,
sternum and pelvis, fifteen complete ribs plus some rib
fragments, the atlas and axis and seven additional cervical vertebrae, four thoracic
vertebrae, the right scapula, the left coracoid, the humeri, radii, carpometacarpi,
and the first phalanges from the right and left major digit, all of the long bones
of the hindlimb (femora, tibiotarsi, fibulae, tarsometatarsi), and the first phalanx
of the hallux.Partial skeleton, USNM 386428, including the skull and mandible, right coracoid,
eroded sternum and pelvis, some ribs and vertebrae, and the paired scapulae,
humeri, ulnae, radii, femora, tibiotarsi, and tarsometatarsi.
Partial skeleton, USNM 386427, including the mandible, furcula,
sternum, pelvis, a vertebra and a fib, and the long bones of the pectoral skeleton from the left side.
Partial skeleton, BBM-X 153649, including the skull, palatines, pterygoids,
quadrates, mandible, furcula,
sternum, pelvis, some fibs, vertebrae, and tracheal
tings, all of the long bones of the pectoral skeleton except one radius, all of the
long bones of the hindlimb except one fibula, plus two pedal and one ungual
phalanges.Partial skeleton, BBM-X 153654, including the skull, mandible, eroded left
humerus, and the femora and tarsometatarsi.
Partial skeleton, BBM-X 153648, including the skull and mandible, furcula,
eroded sternum and pelvis, and some bone fragments.
Associated mandible and tibiotarsus, BBM-X 153651.
Measurements of Paratypes: See Table 1.
Diagnosis: A large species of Corvus with a high, arched bill. The bill is broader
and deeper than in C. woodfordi or C. meeki. Compared to C. macrorhynchus,
C. corax, and C. moriorum, the nostril is less elongated anteroposteriorly, the
membranes in the nasal cavities are more extensively ossified, and the interorbital
septurn is not fenestrated. C. impluviatus differs further from C. macrorhynchus
in having the bill shorter and deeper; from C. corax in having the bill deeper and
the dorsal nasal bar broader; and from C. moriorum in having the bill more
arched, the cranial fenestra smaller or absent, and the articular end of the mandible
larger. Compared to C. hawaiiensis and C. viriosus, new species, the maxilla is
deeper and more arched, the dorsal and lateral nasal bars are wider, the ossification
of membranes in the nasal cavities is more extensive (including ossification of
the nasal septum, floor of the nasal cavity, and the partial occlusion of the narial
openings), the zygomatic process is broader, the olecranon is slimmer, and the
posterior projection of the ilium is longer and slimmer. C. impluviatus differs
further from C. viriosus but agrees with C. hawaiiensis in having a relatively short
bill, with a less excavated ventral surface of the maxilla, a broader frontal, broad
postorbital processes, broad and rounded rather than square-tipped transpalatine
processes, and the mandible with a shorter symphysis, a more decurved tomial
crest, and with a slight ventral projection to the posterior fossa that is not developed
in C. viriosus.
Remarks: The postcranial bones of C. impluviatus average longer than those of
C. hawaiiensis or C. viriosus, although the average size difference between C.
impluviatus and C. viriosus is generally slight (Table 1). The short, arched bill and
the extensive ossification within the nasal and orbital cavities are very distinctive
characters of this spedes. See further remarks under the following species. |
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