In Depth
Nannopterygius was first described in 1871 by John Hulke, but as a species of Ichthyosaurus, I. enthekiodon. However, the Ichthyosaurus genus 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 enthekiodon as Nannopterygius. Nannopterygius is today considered to be identified as an ophthalmosaurid ichthyosaur not only indicating that Nannopterygius was a relative to the famous Ophthalmosaurus, but that 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.
Further Reading
- 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 Zusammenh�nge. - Verlag von Gebr�der Borntraeger, Berlin, 114 pp 22 pls. - Friedrich von Huene 1922. - The Ichthyosauria. Stuttgarter Beitr�ge zur Naturkunde, Serie B. - Geologie und Pal�ontologie), 298, 1–159. - M. W. Maisch & A. T. Matzke - 2000. – Revision of Nannopterygius (Ichthyosauria: Ophthalmosauridae): reappraisal of the ‘inaccessible’ holotype resolves a taxonomic tangle and reveals an obscure ophthalmosaurid lineage with a wide distribution -. Zoological Journal of the Linnean Society. – Nikolay G. Zverkov & Megan L. Jacobs – 2020.
