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Plesiopterys, new plesiosaur from Germany
from: Ben Creisler firstname.lastname@example.org
The new Journal of Paleontology has a new plesiosaur. I'm
a bit queasy about the spelling of the name (getting
from "pteryx" to "pterys" is pretty weird), but it will
have to stand I guess.
O'KEEFE, F. ROBIN, 2004. PRELIMINARY DESCRIPTION AND
PHYLOGENETIC POSITION OF A NEW PLESIOSAUR (REPTILIA:
SAUROPTERYGIA) FROM THE TOARCIAN OF HOLZMADEN, GERMANY.
Journal of Paleontology 78 (5): 973-988.
This paper offers a preliminary description of a
plesiosaur (Reptilia: Sauropterygia) from the Lower
Toarcian Posidonienschiefer near the village of Holzmaden
in Baden-Württemberg, Germany, and discusses its
phylogenetic relevance. This new taxon, Plesiopterys
wildi , new genus and species, is remarkable in its
retention of several plesiomorphic features. A
phylogenetic analysis places Plesiopterys as the sister
group of the Plesiosauroidea, and as such the taxon is the
most basal taxon yet known on the branch leading to this
major clade. Plesiopterys possesses a high count of
cervical vertebrae and a relatively small head, yet the
limbs and limb girdles are plesiomorphic in proportion.
The skull displays a mosaic of features, reminiscent of
both Thalassiodracon <and the rhomaleosaurids in some
characters, yet similar to Plesiosaurus in others. The
basicranium is plesiomorphic and resembles that of
nothosaur-grade sauropterygians in several respects. A
faunal comparison between Holzmaden and the Lower Toarcian
deposits on the Yorkshire coast of England concludes that
the Holzmaden fauna is more plesiomorphic than the roughly
coeval Yorkshire fauna in two of three plesiosaur
Plesiopterys wildi n. sp., by monotypy.
As for species.
Plesio-, Gr. near, close, old; -pterys ,Gr. wing. The
latter also refers to the pterygoid bone, which is an
important feature of this taxon.
A small plesiosaur possessing 39 cervical vertebrae, a
relatively small skull (17 percent of neck length,
compared to 28 percent of neck length in
Thalassiodracon)...., and plesiomorphic proportions of the
limbs and limb girdles. The skull is unique among
plesiosaurs in the retention of grooves for the internal
carotid artery on the dorsal surface of the pterygoid. The
mandible possesses a short symphysis (number of tooth
positions not determinable) without participation of the
splenial, but retains a ventral mandibular ridge.
Autapomorphies include: quadrate flange of the pterygoid
is straight and narrow, and expands into a wide boss at
its terminus; possession of flanges of the pterygoid
dorsal to the plane of the palate in the anterior of the
posterior interpterygoid vacuities; exposure of the
cultriform process of the parasphenoid almost to margin of
anterior pterygoid vacuity; large anterior interpterygoid
vacuity with round posterior margin and pointed anterior
Named for R. Wild, in recognition of his many
contributions to the vertebrate paleobiology of the German
SMNS 16812, a complete skeleton on display in the
Staatliches Museum für Naturkunde, Stuttgart, Germany.