Promissum

Promissum; Temporal range: Ordovician–Devonian PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	†Conodonta
(unranked):	†Prioniodontida
Order:	†Prioniodinina
Family:	†Balognathidae
Genus:	†Promissum; Gabbott, Aldridge & Theron 1995

Promissum is an extinct genus of conodonts, primitive chordates, that lived from the Ordovician to the Devonian period (about 500 million years ago). Some call it the Niagara Foundation fish.

A conodont, Promissum had a primitive mouth under its eyes with mineralized teeth, which are both typical for conodonts. It had a primitive backbone and 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 cm (16 inch) in length.^[2]

Well-preserved specimens were discovered in the Soom shale of South Africa in 1994.^[3]

Promissum was probably capable of maintaining a cruising speed, but not of bursts of speed.^[3]

The type species is Promissum pulchrum.^[3]

References

^ Gabbott, S.E.; Aldridge, R.J.; Theron, J.N. (1998). "Chitinozoan chains and cocoons from the Upper Ordovician Soom Shale lagerstatte, South Africa; implications for affinity". Journal of the Geological Society. 155 (3): 447–452. doi:10.1144/gsjgs.155.3.0447.
^ Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 23. ISBN 1-84028-152-9.
^ ^a ^b ^c Gabbott, S.E.; R. J. Aldridge; J. N. Theron (1995). "A giant conodont with preserved muscle tissue from the Upper Ordovician of South Africa". Nature. 374 (6525): 800–803. doi:10.1038/374800a0.