What is it about?
Belemnites, extinct cephalopods related to modern squids and cuttlefish, are well represented in the fossil fauna of the Jurassic and Cretaceous in many parts of the world. However, they have not been systematically studied in Alaska. Our work, which is based on Middle Jurassic specimens in museums and new collections from Southcentral Alaska, presents a new genus and species, as well as two new species within a genus known previously only in Europe.
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Why is it important?
We believe that the new genus (Pseudosimobelus) represents a transitional form between the families Megateuthididae and Cylindroteuthididae. We postulate that these Alaskan belemnites migrated in a westward direction from the Jurassic Tethys Ocean into the eastern Pacific via a marine passage known as the "Hispanic Corridor". Our findings provide evidence that the Peninsular terrane, one of the "building blocks" of Alaska, was located south of its present location in the Bajocian Stage of the Middle Jurassic.
Perspectives
The fossil "guards" of belemnites are familiar to many field workers in geology but details of their evolution and migrations in the Mesozoic northeastern Pacific are not well documented. This project created an opportunity for collaboration between Alaskan and Russian geologists/palaeontologists and has led to some unexpected findings and new taxa. The field work in remote parts of Alaska and the discovery of museum specimens that have never been examined is very exciting.
Cynthia Schraer
Read the Original
This page is a summary of: Early Bajocian belemnites of Southcentral Alaska: new data and new perspectives on mid-Middle Jurassic Megateuthididae and Belemnopseidae biogeography, Journal of Systematic Palaeontology, August 2018, Taylor & Francis,
DOI: 10.1080/14772019.2018.1486335.
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