Karyakino (Cretaceous of Russian Federation)

Also known as Plesiosaur locality

Where: Saratov, Russian Federation (44.7° N, 39.1° E: paleocoordinates 35.4° N, 35.8° E)

• coordinate estimated from map

• small collection-level geographic resolution

When: Rybushka Formation, Campanian (83.6 - 72.1 Ma)

• The majority of reptiles and birds come from Bed 5. The bones are light brown, considerably phosphatized, very dense, rolled, subject to bioerosion, with various orientations in the bed. The lower jaw of the polycotylid described was in the section directly above the phosphorite horizon

• group of beds-level stratigraphic resolution

Environment/lithology: marine; sandstone and burrowed, medium-grained, glauconitic, phosphatic, quartzose, green sandstone

• K2 Cmp 2 , Bed 4. Medium-grained quartz-glauconitic (the ratio about 1 : 1) sand; in the upper part, the matter is yellowish green; in the lower part, it is dull green. In the upper part (0.2 m below the roof), there are subhorizontally positioned burrows filled by the matter of the bed. Below, down to the bottom, there are whitish subvertical and subhorizontal burrows 1–2 cm in diameter, filled with more carbonate matter and lacking glauconitic grains in the core. Phosphoritic inclusions are uniformly scattered throughout the bed. The bed has yielded coprolites, bone remains of sharks, bony fish, and reptiles. The boundary with the underlying bed is distinct, uneven. The bed is 0.7 m thick.

•K2 Cmp 1–2 , Bed 5. Phosphoritic horizon. Phosphorite inclusions are distributed nonuniformly along the strike, forming in places lenticular accumulations. In some sites, the horizon is nonuniformly colored by reddish brown spots of iron hydroxide. The cementing matter is the psammitic component of the overlying bed. The boundary with the underlying bed is distinct, uneven. The bed has yielded teeth of sharks, dental plates of chimaerae, vertebrae of cartilaginous and bony fishes, bones of marine reptiles, pterosaurs, and birds (Hesperornites), abundant coprolites of aquatic vertebrates, fragments of molds of the gastropod Solariella sp., shells and imprints of the bivalves Monticulina sp., Gryphaeostrea sp., and Chlamys sp. The bed is 0.1–0.15 m thick.

Size class: macrofossils

Collected by M.A. Grigor’ev in 2004

Collection methods: surface (in situ)

• Department of Historical Geology and Paleontology of Saratov State University (SGU)

Primary reference: M. S. Arkhangelsky, A. O. Averianov, and E. M. Pervushov. 2007. Short-necked plesiosaurs of the Family Polycotylidae from the Campanian of the Saratov Region. Paleontological Journal 41(6):656-660 [P. Mannion/J. Tennant/R. Benson]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 141001: authorized by Philip Mannion, entered by Jonathan Tennant on 20.03.2013, edited by Roger Benson

Creative Commons license: CC BY (attribution)

Taxonomic list

• The section is well described by faunal remains of both invertebrates and vertebrates. The material was collected and determined by workers of SGU (Ivanov, 1996; Pervushov, 1998; Pervushov et al., 1999, 2001).

•The bed has yielded teeth of sharks, dental plates of chimaerae, vertebrae of cartilaginous and bony fishes, bones of marine reptiles, pterosaurs, and birds (Hesperornites), abundant coprolites of aquatic vertebrates, fragments of molds of the gastropod Solariella sp., shells and imprints of the bivalves Monticulina sp., Gryphaeostrea sp., and Chlamys sp

unclassified
  -
Bivalvia
 Ostreida - Gryphaeidae
Monticulina sp. Ivanov 1995 oyster
Gryphaeostrea sp. Conrad 1865 oyster
Gastropoda
 Trochoidea - Trochidae
Solariella sp. Wood 1842 top snail
Aves
 Ornithurae -
Hesperornithiformes sp. Fürbringer 1888 bird
Reptilia
 Sauropterygia - Polycotylidae
Polycotylidae indet. Williston 1908 plesiosaur
SGU 104a/37, fragment of mandibular rostrum