The narrow wings, Stenopterygius (1904)
Phylum : Chordata
Class : Reptilia
Order : Ichthyosauria
Family : Stenopterygiidae
Genus : Stenopterygius
Species : S. quadriscissus, S. triscissus, S. uniter, S. aaleniensis
Stenopterygius was a typical, dolphin-shaped ichthyosaur of the early Jurassic period, similar in build, if not size, to the poster genus of the ichthyosaur family, Ichthyosaurus. With its narrow flippers and smaller head, Stenopterygius was more streamlined than the earlier ichthyosaurs of the Triassic period, and likely swam much faster in pursuit of prey.
Various Stenopterygius fossils have been identified harboring the remains of juveniles - clearly instances of mothers dying before they could give birth. As with most other ichthyosaurs, it’s now believed that Stenopterygius females gave birth to live young, rather than crawling onto dry land and laying eggs like other reptiles.