Kaylaka Formation

The Kaylaka Formation,^[1] also known as the Kajlâka Formation, is a Late Cretaceous (Maastrichtian)^[2] geologic formation located within Bisserna Cave, Shumen,^[3] and Labirinta Cave, Vratsa Province, both in Bulgaria.^[1]

Kaylaka Formation
Stratigraphic range: Maastrichtian PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Unit of	Eastern Fore-Balkan Zone
Underlies	Kamendel Formation
Overlies	Mezdren Formation and Dobrina Formation
Lithology
Primary	Limestone
Location
Coordinates	43.15°N 26.53°E / 43.15; 26.53
Region	Shumen Province and Vratsa Province
Country	Bulgaria
Extent	Bisserna Cave and Labirinta Cave
Kaylaka Formation (Bulgaria)

History

The first fossils found in the Kaylaka Formation were discovered in 1985 and were described in 2006.^[1]

The hadrosauroid specimen discovered in 1985 was described in 2024.^[4]

Paleofauna

• Anapachydiscus (Menuites) cf. terminus^[1]
• Anomotodon sp.^[1]
• Elasmosauridae? indet.^[1]
• Hadrosauroidea indet.^[4]
• Hemipneustes striatoradiatus^[5][1]
• Hoploscaphites constrictus^[1]
• Mosasauridae indet.^[1]
• Mosasaurus cf. hoffmanni^[1]
• Squalicorax pristodontus^[1]