A
Fig. 85. Stenopterygius megacephalus (BSP 1940/15). A) complete skeleton. B) skull. Scales equal 100 mm.
Remarks: This small species lacks any striking distinguishing
features. Unlike S. quadriscissus and S. hauffianus,
there is no tendency towards tooth reduction. Therefore, it
is difficult to unders tand why Maisch (1998B: 40 6 ) syno-
nymized this species with S. quadriscissus.
Huene (1949) did not give any diagnostic features for the
species S. promegacephalus, but said it was similar to S. megacephalus,
to which he believed it gave rise. It is here considered
a subjective junior synonym of S. megacephalus. Maisch
(1998B: 410, 417) synonymized it with S. megalorhinus.
Huene (1931A: 355) designated a variant of S. quadriscissus
as S. quadriscissus mut. incessa, figuring two skeletons
(1931a, pi. 1, figs 1-2) and listing several other specimens
that he considered referable to this taxon. Included
among these was “the skin specimen in Oxford”, which
can only be OUMNH JZ163. McGowan (1979B: 108) referred
the latter specimen to Stenopterygius megacephalus.
Huene’s other referred specimens have yet to be located.
Plate 13
Stenopterygius megacephalus, BSPM 1940/15. Scale measures 500 mm.
Fig. 86. Stenopterygius megalorhinus (GPIT PV24306). A) complete skeleton. B) skull, modified in posterior region. Scales equal 100 mm.
Stenopterygius megalorhinus Huene, 1922
Fig. 86
Stenopterygius sp. A bel, 1919: fig. 380
Stenopterygius megalorhinus Huene, 1922; 49 [partim]
Stenopterygius uniter H uene, 1931A: 366
Stenopterygius megalorhinus; H uene, 1949: 84
Stenopterygius megalorhinus; Huene, 1952: 58
Stenopterygius megalorhinus; H aufe, 1953: pi. 13a
Stenopterygius quadriscissus (Quenstedt, 1856); Godefroit,
1994: 41-43
Type material: The first specimen cited by Huene is a
complete skeleton housed in the Benedictine Monastery at
Kremsmunster, Austria (Huene, 1922: 49, pi. 9, fig. 1). This
complete and well preserved skeleton (BMK 813B) was
designated as the lectotype by McGowan (1979B: 110).
Diagnosis: Teeth numerous with no tendency toward reduction
in size or number. Presacral vertebrae <45; preflex-
ural vertebrae usually <80, but >75. Skull appears long and
slender, with long snout, but snout ratio probably <0.70,
but >0.64; premaxillary ratio >0.42. Orbit not especially
large, orbital ratio <0.22. Forefins elongate, distal elements
probably well spaced, aspect ratio >2.7. Moderate sized,
total length <3.5 m; skull length <650 mm.
Occurrence: Primarily from Holzmaden area, southern
Germany.
Stratigraphic range: Upper Lias; Lower Jurassic (Toar-
cian).
Remarks: A s dis cus sed elsewhere (McGowan, 1979B:
110), the second of Huene’s (1922: 49) syntypes, SMNS
4996, does not appear to belong to the same ta xon as the
first. This specimen, a partial skeleton, was damaged by
fire, and all that remains now is the skull. This has been
referred to Temnodontosaurus trigonodon (McGowan, 1979B:
119; at that time, the specimen was referred to as T. bur-
gundiae).
Stenopterygius megalorhinus and S. megacephalus bear a
strong superficial resemblance to one another, each being
a fairly modest-sized species, with well-developed teeth.
However, closer inspection reveals distinct differences.
S. megacephalus has lower presacral and preflexural vertebral
counts, and the forefin is much more elongate, with a
higher aspect ratio.
Stenopterygius longipes (Wurstemberger, 1876)
Fig. 87
Ichthyosaurus longipes Wurstemberger, 1876: 229
Leptopterygius acutirostris; Kuhn, 1934: 60 [partim]
Stenopterygius longipes; McGowan, 1979B: 111
Holotype: GPIT 1491/5, a complete but poorly preserved
skeleton from which few measurements can be taken.
Diagnosis: Fins long and slender, aspect ratio of forefin
>3.0. Preflexural vertebrae <75. Skull large, teeth well developed,
without tendency toward degeneration. Large
ichthyosaurs, total length >3.5 m, skull length >700 mm.
Occurrence: Holzmaden, Germany.
Stratigraphic range: Upper Lias; Lower Jurassic (Toar-
cian).
Remarks: The feature that sets Stenopterygius longipes
apart from all other Toarcian species is its remarkably low