Safekipedia

Stensioella

Adapted from Wikipedia · Discoverer experience

A fossil of Stensioella heintzi, an ancient marine organism, displayed at the American Museum of Natural History.

Stensioella refers to a special kind of ancient fish called Stensioella heintzi. This creature lived a very long time ago during a period known as the Lower Devonian. We only know about it because scientists found its fossils in a place called the Hunsrück slate in Germany.

The name Stensioella comes from a scientist named Erik Stensiö, who did important work studying old fish. The second part of the name, heintzi, honors another scientist called Anatol Heintz.

This fish is quite mysterious, and scientists are still learning about where it fits among other ancient fish groups. It belongs to a group of fish called placoderms, which had armored plates on their bodies instead of bones like fish do today. Studying creatures like Stensioella helps us understand more about life from millions of years ago.

Anatomy

Stensioella heintzi had a long body, a tail like a whip, and big, wing-like fins near its chest. It would have looked a bit like a stretched-out ratfish. Just like the Gemuendina, which lived at the same time, S. heintzi had tough armor made from many small, scale-like pieces called tubercles.

Taxonomy

Stensioella is thought to be one of the earliest types of placoderms, a group of ancient fish-like creatures. Scientists noticed that the shoulder joints of its armor look a lot like those of other placoderms. However, because we only have one complete specimen, some experts aren't fully sure it belongs to this group.

One scientist, Philippe Janvier, believes Stensioella might actually belong to a different group called holocephalids, which includes modern chimaeras. If this were true, it would mean that holocephalids split from sharks even before a big period of evolution in the Devonian time. But others disagree, saying Stensioella doesn't share many other features with holocephalids aside from a general shape similar to some early ones like Menaspis.

Images

An ancient ammonite fossil from the Jurassic period, discovered in Bavaria, Germany.
Scientific drawing showing the head area of Pikaia, an ancient sea creature, with its gills.
A hagfish (Myxine glutinosa), a unique deep-sea fish known for its ability to produce slime.
An artist’s restoration of Conodonta, an ancient jawless fish from the fossil record.
Scientific illustration of Coccosteus, an armored fish from the ancient Devonian period.
Artist's reconstruction of Ischnacanthus gracilis, an ancient spiny fish from the Devonian period.
A scientist's drawing of Ctenacanthus concinnus, an ancient fish that lived during the Devonian period millions of years ago.
A scientific artist's reconstruction of Dunkleosteus terrelli, an ancient armored fish that lived millions of years ago.
Scientific illustration of Palaeacanthaspis vasta, an armored ancient fish from the Devonian period.
Scientific restoration of Astraspis desiderata, an early chordate from the Ordovician period.
An artist's reconstruction of Qingmenodus, an ancient fish that lived during the Devonian period.

Related articles

Devonian

This article is a child-friendly adaptation of the Wikipedia article on Stensioella, available under CC BY-SA 4.0.

Images from Wikimedia Commons. Tap any image to view credits and license.