Baissa (PIN collection 3064, bed 32): Aptian, Russian Federation

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Insecta - Mantodea - Cretomantidae
1 specimen
PIN 3064/8511
Insecta - Coleoptera - Carabidae
Nikolajev 1992 1 specimen
PIN 3064/7145 (2 measurements)
see common names

Geography
Country:Russian Federation State/province:Buryatia
Coordinates: 53.3° North, 112.1° East (view map)
Paleocoordinates:50.9° North, 119.4° East (Wright 2013)
Basis of coordinate:based on nearby landmark
Geographic resolution:outcrop
Time
Period: Cretaceous Epoch: Early Cretaceous
Stage: Aptian 10 m.y. bin: Cretaceous 3
Key time interval: Aptian
Age range of interval: 121.4 - 113.2 m.y. ago
Stratigraphy
Formation:Zaza
Stratigraphic resolution:bed
Stratigraphy comments: C. longipoda, E. trisetalis and Lycoptera all occur in the Zaza Formation indicating that this formation could be correlated with the upper Yixian Formation and the lower Jiufotang Formation in western Liaoning, which have a duration of 122.5-120 Ma. So it is possible to assign the Zaza Formation to an Aptian age. Also correlated with Barremian-Aptian based on plants and pollen.
Lithology and environment
Primary lithology: lithified marl
Secondary lithology: lithified carbonaceous siltstone
Environment:lacustrine - large Tectonic setting:rift
Geology comments: "The water body is reconstructed as an intermontane lake with the depth of 20 - 30 meters (LYAMINA 1980) situated within a granite massif. The presence of thick layers of the bituminous shales shows that the lake was meromictic, with the oxygen deficiency and high hydrogen sulphur level in the hypolimnion. However, the oxygenated epilimnion should be thick, with a lower boundary well beneath the limit of episodic wave action because no suffocation events are documented. The abundance of caddisflies, dobsonfly larvae and other groups intolerant to oxygen deficiency shows that in more shallow areas the water was clear and well-oxygenated even near the bottom. The lake ecosystem was highly productive as indicated by its complex trophic structure (Fig. 2) with several levels of predators up to the large sturgeon-like fish Stychopterus as well as by the extremely high abundance of planetonivorous phantom midges (SINICHENKOVA & ZHERIKHIN 1996)." ZHERIKHIN et al., 1999
Taphonomy
Modes of preservation:mold/impression
Size of fossils:macrofossils
Collection methods and comments
Collection methods:survey of museum collection
Reason for describing collection:taxonomic analysis
Museum repositories:PIN
Metadata
Database number:126065
Authorizer:M. Clapham Enterer:M. Clapham
Modifier:M. Clapham Research group:paleoentomology
Created:2012-03-29 10:26:28 Last modified:2025-02-22 15:12:02
Access level:the public Released:2012-03-29 10:26:28
Creative Commons license:CC0
Reference information

Primary reference:
8897.ETE V. G. Gratshev and V. V. Zherikhin. 1993. New Fossil Mantids (Insecta, Mantida [Sic]). Paleontological Journal 27(1A):148-165 [C. Labandeira/A. Spencer-Lee/M. Clapham]

Secondary references:

50115 G. V. Nikolajev. 1992. Taxonomic criteria and generic composition of Mesozoic lamellicorn beetles (Coleoptera, Scarabaeidae). Paleontological Journal 26(1):96-111 [M. Clapham/M. Clapham]