Kaylaka Formation

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

History
Most of the fossils found in the Kaylaka Formation were discovered in 1985, and were described in 2006; the hadrosauroid specimen was not described until 2024.

Paleofauna

 * Anapachydiscus (Menuites) cf. terminus 
 * Anomotodon sp. 
 * Elasmosauridae? indet. 
 * Hadrosauroidea indet.
 * Hemipneustes striatoradiatus  
 * Hoploscaphites constrictus 
 * Mosasauridae indet. 
 * Mosasaurus cf. hoffmanni 
 * Squalicorax pristodontus