Melanchyn potik, Layer A (Cretaceous of Ukraine)

Where: Ukraine (49.7° N, 31.5° E: paleocoordinates 40.3° N, 28.8° E)

• coordinate stated in text

• outcrop-level geographic resolution

When: Burim Formation, Late/Upper Albian (105.3 - 99.6 Ma)

• Cretaceous sections cropping out in the study area are part of Kaniv dislocations, which refer to the effects of tectonics (glaciogenic dislocation) over the Mesozoic successions (Krochak et al., 2016). The Kaniv dislocations belong to the Burim formation and are commonly exposed in many ravines on the territory of Kaniv Natural Reserve lying on top of the Callovian clays (Krochak et al., 2016). The Burim formation was previously considered Albian in age (Krochak et al., 2016), but more recent macrofaunal, foraminiferal and palynological studies suggested a late Albiane-early Cenomanian age (Ivannik et al., 2014). The lower part of the formation (approximately 20 m) is considered late Albian in age and is characterized by the presence of the ammonite species Mortoniceras inflatum, which indicates an ammonite zone right before the 'Vraconian' according to the stratigraphical data from Central European Basin. Top 40-60 m yielded fossil remains of various foraminifera (e.g., Lingulogavelinella praeformosa, Thalmanninella appenninica) that suggest a latest Albian to early Cenomanian age, including the 'Vraconian' stage (Krochak et al., 2016). Popova et al. (2015) also considered the possibility of the upper layers being Early Cenomanian in age. However, this hypothesis was based on incorrect identifications of several elasmobranch taxa. Paraisurus macrorhizus and Cretoxyrhina vraconensis findings indicate a late Albian age for the sampled deposits.

• bed-level stratigraphic resolution

Environment/lithology: coastal; poorly lithified, glauconitic, quartzose, gray, green sandstone

• Greenish-gray quartz-glauconite sands

Size class: macrofossils

Collected by T. Sokolskyi

Collection methods: bulk, sieve

• Repository: Kiev National Natural History Museum of National Academy of Sciences of Ukraine (NNPM)

Primary reference: T. Sokolskyi and G. Guinot. 2021. Elasmobranch (Chondrichthyes) assemblages from the Albian (Lower Cretaceous) of Ukraine. Cretaceous Research 117(104603) [M. Clapham/M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 214241: authorized by Matthew Clapham, entered by Matthew Clapham on 19.09.2020

Creative Commons license: CC BY (attribution)

Taxonomic list

Chondrichthyes
 Lamniformes - Cretoxyrhinidae
Cretoxyrhina vraconensis Zhelezko 2000 mackerel shark
 Lamniformes - Odontaspididae
Eostriatolamia striatula Dalinkevičius 1935 sand tiger shark
Eostriatolamia subulata Agassiz 1843 sand tiger shark
 Lamniformes - Pseudoscapanorhynchidae
Pseudoscapanorhynchus compressidens Herman 1977 mackerel shark
Protolamna cf. sokolovi Cappetta 1980 mackerel shark
 Lamniformes - Archaeolamnidae
Archaeolamna striata Rogovich 1861 mackerel shark
Archaeolamna ex gr. kopingensis Davis 1890 mackerel shark
 Synechodontiformes - Palaeospinacidae
Synechodus subulatus Rogovich 1861 elasmobranch
 Synechodontiformes - Paraorthacodontidae
Paraorthacodus recurvus Trautschold 1877 elasmobranch
 Squatiniformes - Squatinidae
Squatina (Cretascyllium) cranei Woodward 1888 angel shark
 Heterodontiformes - Heterodontidae
Heterodontus upnikensis Dalinkevičius 1935 bullhead shark