Named By: Friedrich von Huene - 1922.
Synonyms: Ichthyosaurus enthekiodon.
Classification: Chordata, Reptilia, Ichthyosauria, Ophthalmosauria, Ophthalmosauridae.
Species: N. enthekiodon (type).
Size: About 2.5 meters long.
Known locations: England - Kimmeridge Clay Formation. Ichthyosaur remains from Germany might also represent Nannopterygius.
Time period: Callovian/Tithonian of the Jurassic.
Fossil representation: Single specimen.
was first described in 1871 by John Hulke, but as a species of
I. enthekiodon. However, the Ichthyosaurus
was once treated as a wastebasket taxon, and many former species of
Ichthyosaurus have now been re-assigned as distinct
genera. This is
what happened later in the early twentieth century when another
palaeontologists Friedrich von Huene renamed Ichthyosaurus
as Nannopterygius. Nannopterygius
is today considered to be
identified as an ophthalmosaurid ichthyosaur
not only indicating that
Nannopterygius was a relative to the famous
Nannopterygius was probably a deep diving
ichthyosaur that would swim
down into the oceanic depths where there was very little light to hunt
deep sea organisms such as squid.
The name Nannopterygius actually means small wing, but in this respect it is the superficial similarity of the fore limb pectoral flipper to a wing that is the focus of this. Despite possible confusion from this, the pectoral fins actually do act in a similar manner to the wings of a plane by generating lift. You see the drawback of being propelled by being pushed from the rear such as tail is that unless you happen to be generating incredible amounts of thrust, you inevitably end up pitching down from the effects of gravity. Using the pectoral fins however, and ichthyosaurs, or fish, or even a submarine for that matter can control the pitch of the body so that upwards, downwards or even just level swimming can be maintained.
- Note on an Ichthyosaurus (I. enthekiodon) from Kimmeridge Bay, Dorset. - Quarterly Journal of the Geological Society, 27, 440–441. - John Hulke - 1871.
- Die Ichthyosaurier des Lias und ihre Zusammenhänge. - Verlag von Gebrüder Borntraeger, Berlin, 114 pp 22 pls. - Friedrich von Huene 1922.
- The Ichthyosauria. Stuttgarter Beiträge zur Naturkunde, Serie B. - Geologie und Paläontologie), 298, 1–159. - M. W. Maisch & A. T. Matzke - 2000.