Baissa (PIN collection 1668, layer 2) (Cretaceous of Russian Federation)

Where: Buryatia, Russian Federation (53.3° N, 112.1° E: paleocoordinates 56.0° N, 108.5° E)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Zaza Formation, Aptian (125.0 - 113.0 Ma)

• 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.

• group of beds-level stratigraphic resolution

Environment/lithology: lacustrine - large; lithified siltstone and lithified marl

• "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

Size class: macrofossils

Preservation: mold/impression

Collected by PIN institute in 1959; reposited in the PIN

Primary reference: D. E. Shcherbakov. 2007. Mesozoic spider mimics — Cretaceous Mimarachnidae fam. n. (Homoptera: Fulgoroidea). Russian Entomological Journal 16(3):259-264 [M. Clapham/J. Karr]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 144924: authorized by Matthew Clapham, entered by Jered Karr on 21.05.2013, edited by Matthew Clapham

Creative Commons license: CC BY (attribution)

Taxonomic list

Insecta
 Hemiptera - Mimarachnidae
Saltissus eskovi Shcherbakov 2007 planthopper
Clavus 1668/1669
 Hemiptera - Palaeoaphididae
Ellinaphidinae indet.1 Kania and Wegierek 2008 aphid
PIN 1668/1700
Ellinaphis sensoriata n. gen. n. sp.3 Shaposhnikov 1979 aphid
PIN 1668/2347
Annulaphis rasnitsyni n. gen. n. sp.3 Shaposhnikov 1979 aphid
PIN 1668/1699(1701)
 Hemiptera - Corixidae
"Baissocorixa jaczewskii" = Diapherinus ornatipennis2
"Baissocorixa jaczewskii" = Diapherinus ornatipennis2 Popov 1966 water boatman
PIN 1668/1694, 1710