- Callovian
The Callovian is a stage on the
geologic time scale occurring 164.7 ± 4.0 Ma to 161.2 ± 4.0 Ma (million years ago).It is the last stage of theMiddle Jurassic .The stage takes its name from an old spelling of
Kellaways Bridge , 3 km north-east of Chippenham inWiltshire inEngland .Geography
During the Callovian,
Europe was an island chain.Vertebrate Fauna
Crocodylomorphs
auropods
Invertebrate Fauna
Ammonitida Members of the order ammonitda are known as Ammonitic ammonites. They are distinguished primarily by their suture lines. In ammonitic suture patterns, the lobes and saddles are much subdivided (fluted) and subdivisions are usually rounded instead of saw-toothed. Ammonoids of this type are the most important species from a biostratigraphical point of view. This suture type is characteristic of
Jurassic andCretaceous ammonoids but extends back all the way to thePermian .Neocoleoids
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