Promissum

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Promissum
Temporal range: Ordovician–Devonian
[1]
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Conodonta
Order: Priodontina
Genus: Promissum
Gabbott, Aldridge & Theron 1995

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 (16 in) 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]

References[edit]

  1. ^ 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. 
  2. ^ Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 23. ISBN 1-84028-152-9. 
  3. ^ a b 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.