Stenopterygius quadriscissus

Overview

Stenopterygius quadriscissus is an ichthyosaur known for a streamlined body, large dorsal fin, and tail fin. The museum introduces specimens preserving the soft outline of the body. This animal allows both bones and body contours to be explored together.^[1][2]

Key facts

The museum presents one specimen as having been buried during birth. This is a case in which a fossil preserves clues that raise questions about a moment of reproduction as well as the body’s outline.^[1]

Time and place

It is a Jurassic ichthyosaur. The Jurassic was roughly 200–140 million years ago. Soft-tissue research at genus level and specimen records naming the species convey different information.^[1][3][4]

The time range describes source context, not the complete duration of this species.

Size, form and skeleton

The material describes a streamlined body outline, a large dorsal fin, and a tall tail fin. Two pairs of paddles connected to the body and a vertical tail are its main construction. The front and rear fins can be examined separately.^[1][2]

According to a research account from the Stuttgart State Museum of Natural History, adult body length is about 2–3.5m.^[5]

Habitat and reproduction

What fossil led to the interpretation of burial during birth? The museum describes the body and preservation of a specimen with the species specified. This is a case of exploring reproductive questions through an animal’s skeleton.^[1]

Fossil discovery

The museum’s specimen description presents the soft outline of the body and the interpretation of birth. A separate plate caption for SMF457 records a large dorsal fin and tail fin. Several specimens add different information about the body.^[1][2]

References

1. American Museum of Natural History — Stenopterygius quadriscissus
2. Research plate explanation for Stenopterygius SMF457
3. Lindgren et al. (2018) — Soft-tissue study of a Jurassic ichthyosaur
4. International Commission on Stratigraphy (2024) — Geological time chart
5. Stuttgart State Museum of Natural History — Study of an Early Jurassic marine predator
6. Andrews (1915) — The skeleton of Ophthalmosaurus icenicus

Research questions

What changes when soft tissues survive, compared with seeing only a skeleton? Genus-level soft-tissue research has also discussed skin, blubber, and pigment cells. The outlines of species-specific specimens can be compared with tissue research on related material.^[3][1]

Observation

Move your gaze from the streamlined body to the large dorsal fin and front and rear paddles. Following through to the vertical tail helps you read the broad body outline together with the positions of several fins.^[1][2]