- Baissa
Baissa is the richest and the most exciting Lower
Cretaceous locality inSiberia , on the left bank of theVitim River . The Zaza Formation sediments exposed at Baissa are represented mostly bysandstone s,siltstone s,marl s and bituminousshale s. The total thickness if the section is about 80 m.Insect remains occur throughout the section, except for the most coarse-grained rocks. Their abundance and state of preservation vary from one bed to another.Baissa is the only locality in the World where 24
pterygote orders are found. These areEphemeroptera ,Odonata ,Grylloblattodea ,Plecoptera ,Blattodea ,Mantodea ,Isoptera ,Dermaptera ,Orthoptera ,Phasmatodea ,Psocoptera ,Phthiraptera ,Thysanoptera ,Hemiptera ,Megaloptera ,Raphidioptera ,Neuroptera ,Coleoptera ,Mecoptera ,Siphonaptera ,Trichoptera ,Diptera ,Lepidoptera , andHymenoptera , comprising in total about 195 families.Excellently preserved
spider s,conchostraca ns,ostracod s,gastropod s,pelecypod s, fresh-waterbryozoa ns,fish es,bird feathers, and diverseplant remains are also known from this site. Several species ofinsect trace fossils have been recorded as well.References
*Zherikhin, V.V., Mostovski, M.B., Vrsansky, P., Blagoderov, V.A. and Lukashevich, E.D. 1999. The unique Lower Cretaceous locality of Baissa and other contemporaneous insect-bearing sites in North and West Transbaikalia. "Proceedings of the First Palaeoentomological Conference, Moscow, 1998". Bratislava: Amba Projects, AM/PFICM98/1.99, pp. 185-192.
External links
* [http://palaeoentomolog.ru/Baissa/tour.html Tour around Baissa]
* [http://palaeoentomolog.ru/Collections/baissa.html Insect collections from Baissa]
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