Promissum
Encyclopedia
Promissum is an extinct genus of primitive chordate
that lived in the Ordovician
period, about 500 million years ago.
A conodont
, Promissum had a primitive mouth under its eyes with mineralized teeth, which are both typical for conodonts, and also a primitive backbone. It probably looked like a small eel
or large worm
, lacking any kind of fins except for perhaps a small one on the tail. It was relatively large for a conodont, reaching about 40 centimetres (15.7 in) in length.
Well-preserved specimens were discovered in the Soom shale
of South Africa
in 1994.
Promissum was probably capable of maintaining a cruising speed, but not of bursts of speed.
Chordate
Chordates are animals which are either vertebrates or one of several closely related invertebrates. They are united by having, for at least some period of their life cycle, a notochord, a hollow dorsal nerve cord, pharyngeal slits, an endostyle, and a post-anal tail...
that lived in the Ordovician
Ordovician
The Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million years ago . It follows the Cambrian Period and is followed by the Silurian Period...
period, about 500 million years ago.
A conodont
Conodont
Conodonts are extinct chordates resembling eels, classified in the class Conodonta. For many years, they were known only from tooth-like microfossils now called conodont elements, found in isolation. Knowledge about soft tissues remains relatively sparse to this day...
, Promissum had a primitive mouth under its eyes with mineralized teeth, which are both typical for conodonts, and also a primitive backbone. It probably looked like a small eel
Eel
Eels are an order of fish, which consists of four suborders, 20 families, 111 genera and approximately 800 species. Most eels are predators...
or large worm
Worm
The term worm refers to an obsolete taxon used by Carolus Linnaeus and Jean-Baptiste Lamarck for all non-arthropod invertebrate animals, and stems from the Old English word wyrm. Currently it is used to describe many different distantly-related animals that typically have a long cylindrical...
, lacking any kind of fins except for perhaps a small one on the tail. It was relatively large for a conodont, reaching about 40 centimetres (15.7 in) in length.
Well-preserved specimens were discovered in the Soom shale
Soom Shale
The Soom Shale is a member of the Late Ordovician Cedarberg Formation in South Africa, renowned for its remarkable preservation of soft-tissue in fossil material....
of South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
in 1994.
Promissum was probably capable of maintaining a cruising speed, but not of bursts of speed.