Cheirothrix
Distribution
Distribution
------------

During the Cretaceous period, sea levels were much higher than they are now. The fish remains at Sahel Alma are very well preserved. The rock is a fine\-grained limestone found in an area much folded and [faulted](/wiki/Fault_%28geology%29 "Fault (geology)") and is laid down in thick beds. The fish may have died because of a localized shortage of [oxygen](/wiki/Oxygen "Oxygen"). Five specimens of *Cheirothrix lewisii* were found, each preserved in such detail that the fifty or so [vertebrae](/wiki/Vertebra "Vertebra") can be counted and the branching rays of the pectoral fins can be seen clearly. The [holotype](/wiki/Holotype "Holotype") is a cleft slab of limestone with remains of the fish on both sides. It is now kept in the [Natural History Museum](/wiki/Natural_History_Museum%2C_London "Natural History Museum, London") in London.

Another member of the genus, *Cheirothrix libanicus*, is found in the same fossil bed and other members of the genus are known from 84\-to\-70\-million\-year\-old deposits in Germany.


How did sea levels change after the Cretaceous period?