gie und historische Geologie, München, is referable to
Brachyptery gius. She also referred an isolated basioccipital
from Madagascar to B. extremus (Fernändez, 1997B).
The holotype of Brachypterygius zhuravlevi A rkhangel-
SKY (1998A: fig. 4 ) comprises a humerus and three associated
bones from the middle Volgian of the Saratov Region
of Russia. The humerus, figured from the distal aspect, is
depicted as having a very narrow rectangular facet for the
intermedium. There are no illustrations of the distal end of
the humerus in the holotype of B. extremus, but, in planar
view (Huene, 1922: pi. 19, fig. 9), it looks much like that of
B. zhuravlevi (Arkhangelsky, 1998A: fig. 4). As there are no
inconsistencies between the two, B. zhuravlevi is considered
a subjective junior synonym of B. extremus.
Efimov (1998: fig. 4) identified five digits for the forefin
of Otschevia pseudoscythica, whereas the holotype of Brachy-
pterygius extremus has six. As in the case of B. mordax, this
is not considered a major difference, and Efimov’s (1998)
new taxon is accordingly synonymized with B. extremus.
Brachyptery gius cantabrigiensis (Lydekker, 1888)
Ophthalmosaurus cantabrigiensis L ydekker, 1888: 310
Ophthalmosaurus(?) cantabrigiensis L ydekker, 1889A: 8-9
Ophthalmosaurus cantabrigiensis; Huene, 1922: 96
Holotype: BMNH 43989, a small, isolated humerus (Fig.
48).
Diagnosis: Of the three distal facets of the humerus, the
middle one is largest; facets for radius and ulna subequal;
free margins of anterior and posterior facets rounded.
Apparently small ichthyosaur, humerus perhaps <80 mm
long.
Occurrence: Cambridgeshire, England.
Stratigraphic range: Upper Greensand; Lower Cretaceous
(Albian).
Remarks: Lydekker (1888: 312) gave a very brief description
of the holotypic humerus, comparing it with that of
Ophthalmosaurus icenicus. The following year, L ydekker
(1889A: 9, fig. 6) identified and figured the holotype as a
right humerus, thinking the smaller of the distal facets was
for a pisiform element, as was then believed to be present
in Ophthalmosaurus. As noted in the descriptive section,
most other authors similarly confused left with right when
describing the humeri of Ophthalmosaurus. The holotype is
actually a left humerus (Fig. 48). Some isolated basioccip-
itals from the Cambridge Upper Greensand are also referable
to this species, on account of their similarity with
those of Brachyptery gius extremus.
Genus A e g iro sa u ru s Bardet et FernAndez, 2000
Type species: Aegirosaurus leptospondylus (Wagner, 1853)
Diagnosis: Humerus with three distal facets, the middle
one, for intermedium, being smallest, the anterior one, for
the radius, being larger than the posterior ulna facet. Six
digits, elements in longest digit probably > 2 0 . Pre- and
post-axial accessory elements contact radius and ulna respectively,
without contacting humerus; phalanges tightly
packed, polygonal rather than rounded, and not obviously
rectangular. Teeth small, numerous, strongly anchored and
not lost. Snout long and slender, snout ratio may exceed
0.66. Orbit medium-sized, orbital ratio may exceed 0.20.
Postorbital region narrow. Dorsal margin of external naris
extends ventrally, giving kidney-shaped outline. Pelvic
girdle bipartite, ischium and pubis fused to form single
element, without a foramen. Preflexural vertebrae > 8 0 .
Aegirosaurus leptospondylus (Wagner, 1853)
Ichthyosaurus leptospondylus W agner, 1853: 26
Aegirosaurus leptospondylus Bardet & FernAndez, 2 0 0 0 :5 0 4
Holotype: Destroyed during WW II.
Neotype: An unnumbered, almost complete skeleton in
the Schwegler Museum, Langenaltheim, Germany.
Diagnosis: As for genus.
Occurrence: Apfeltal, south of Solnhofen, Bavaria, Germany.
Stratigraphic range: Solnhofen Formation; Upper Jurassic
(lower Tithonian).
Remarks: A referred specimen, BSP 1954 I 608, was cited
in McGowan (1976: 670) as “Munich 5”, and thought conceivably
to have been Wagner’s (1853) more complete
specimen. However, as Bardet & FernAndez (2000: 505)
pointed out, the old ichthyosaur collection of the Bayer-
ische Staatssammlung was completely destroyed during
World War II.
Genus Platypterygius Huene, 1922
Myopterygius Huene, 1922: 98
Platypterygius Huene, 1922: 99
Myobradypterygius Huene, 1927: 27
Simbirskiasaurus Ochev & E fimov, 1985: 76
Plutoniosaurus E fimov, 1997: 77
Longirostria Arkhangelsky, 1998B: 66
Pervushovisaurus Arkhangelsky, 1998B: 66
Tenuirostria Arkhangelsk*, 1998B: 66
Type species: Platypterygius platydactylus (Broili, 1907).
Diagnosis: Humerus with two distal facets, for radius and
ulna; radial facet, the smaller, set off obliquely from ulnar
facet such that its anterior margin is well proximal to its
posterior margin; ulna wider (anteroposteriorly) than radius.
No fewer than 7 digits; preaxial and postaxial accessory
digits each exceeding one; crescentic pre- and postaxial
accessory elements probably contact the humerus, possibly
via a small facet; intermedium does not contact humerus;
phalanges characteristically rectangular, except towards
distal tip; elements in longest digit >25, and probably
>30. Teeth numerous, robust, unreduced and well anchored
in dental grooves; orbit small, orbital ratio <0.20;
snout long, snout ratio probably >0.66; maxilla long and
slender, extending well forward of external nares, premaxillary
ratio probably <0.42; nares set well back, prenarial
ratio >0.52; a small, prenarial foramen is probably present,
anterior to the external nares. Extracondylar area of basioccipital
not extensive and not clearly set off from condyle;
anterior surface of basioccipital flat, oblique, and facing
antero-ventrally; no basioccipital peg.
Remarks: Huene (1922: 98-99) proposed the genus Myopterygius
for reception of the English Cretaceous species
Ichthyosaurus campylodon Carter, 1846A, and for two continental
European species, I. strombecki Meyer, 1862, and
I. hildesiensis Koken, 1883, both based upon fragmentary
material. The generic name was selected to reflect the large
trochanters on the humerus and femur. Platypterygius was
erected for reception of Broili’s (1907) I. platydactylus. Presumably
the name was chosen for the flatness, or breadth,
of the forefin. The trochanters (dorsal process and delto-
pectoral crest) are no more extensively developed in the
humerus of I. strombecki or I. hildesiensis than in I. platydactylus.
There are, therefore, no grounds for placing I. campylodon
and I. platydactylus in separate genera. I. campylodon
was erected upon rather fragmentary material, whereas
I. platydactylus was based upon an almost entire skeleton,
and is consequently the type species. The appropriate generic
name is thus Platypterygius (McGowan, 1972C).
Huene (1927) described and figured a partial forefin
from the Lower Cretaceous of Argentina, which he considered
sufficiently different to erect a new genus, Myobradypterygius.
However, the fin is consistent with that of Platypterygius,
with which Myobradypterygius is synonymized.
Simbirskiasaurus birjukovi, from the Lower Cretaceous
(Hauterivian) of the Ul’yanovsk Region of Russia, is based
upon a largely indeterminate partial skull, with associated
vertebrae. Only two diagnostic features can be discerned:
the teeth are unreduced, and two foramina occur, immediately
posterior to the external naris. Other diagnostic features
were listed (Ochev & E fimov, 1985: 77) but these are
either typical of other taxa (e.g., jugal does not reach premaxilla),
or uninformative (“jaw bones long but do not
extend to margins of external nasal apertures”). Some
specimens of Platypterygius australis have a small foramen
anterior to the external naris (W ade, 1984). An acid-prepared
skull of P. australis, in the Natural History Museum,
London (BMNH R16400), has an anterior and a posterior
foramen, suggesting that the occurrence of foramina in the
vicinity of the external naris is quite variable. The features
of Simbirskiasaurus are, therefore, not inconsistent with
those of Platypterygius, and the former genus is considered
a subjective junior synonym of the latter.
E fimov (1997) proposed Plutoniosaurus for a new species,
P. bedengensis, represented by a partial skeleton from
the Lower Cretaceous (Hauterivian) of the Ul’yanovsk
Region of Russia. The stylized drawing of the holotype
lacks any detail, but is not inconsistent with Platypterygius.
However, E fimov (1997: 78) noted that his new genus
lacked an anterior emargination in the coracoid, and that
the fin was symmetrical, “not asymmetric with longer
middle digits, as typical of Platypterygius.” Given the incompleteness
of his material (only 21 elements in the longest
digit compared with over 30) it is not possible to judge
the symmetry of the forefins. As for the emargination of the
coracoid, it is known to be a variable feature in some taxa
(McGowan, 1979B: 104). Furthermore, it appears that the
emargination grows with a markedly negative allometry,
and is barely developed in large individuals (Wade, 1984:
106, fig. 4). Even if the feature was entirely absent, such a
minor difference does not warrant generic distinction. As
there are no inconsistencies between Plutoniosaurus and
Platypterygius, the former is synonymized with the latter.
Arkhangelsk* (1998B) erected four subgenera, Longirostria,
Pervushovisaurus, Platypterygius and Tenuirostria, diagnosed
partly on size differences. These subgenera are
considered unfounded, and all are synonymized with
Platypterygius.
A number of species have been described from the
Cretaceous, but most were based on indeterminate material
and should be treated as nomina dubia (McGowan,
1972C). Seven valid species were recognized by McGowan
(1972C), but this is still overinflated, and is here further
reduced to five. Most of these are rather poorly known,
and if more data were available to allow adequate comparisons,
fewer species would probably be justified. However,
these five will be retained for the present as repositories for
material from different geographical and geological provinces.
Their respective diagnoses reflect the present lack of
discrimination among the referred species. A rkhangelsky
(1998B) added additional new names, based on incomplete
material, to this already inflated taxonomy.
Platypterygius platydactylus (Broili, 1907)
Fig. 95
Ichthyosaurus platydactylus Broili, 1907: 159
Platypterygius platydactylus; H uene, 1922: 99
Ichthyosaurus (Platypterygius) platydactylus; Kuhn, 1946: 79
Ichthyosaurus (Platypterygius) hercynicus Kuhn, 1946: 80
Platypterygius platydactylus; McGowan, 1972C: 17