MIOCENE WHALES
Primitive whales (Achaeoceti) are extinct whales whose structure and appearance are reconstructed based on the fossil remains. Here, fossil remains of whales were found near Susedgrad and Vrapče near Zagreb. The most famous one is the Mesocetus Agrami, the so-called Zagreb's whale. Apart from this whale, the remains of ribs and large vertebrae of another whale were discovered at the Vranić site below Papuk. The quantity and the preservation of fossil finds are not sufficient for a closer determination of the genus and species. However, based on the analogy with the worldwide finds of whales from this period, it can be concluded that Miocene whales were much smaller than today's whales, the largest ever living animals on Earth.
DOLPHIN FOSSILS
In Croatia, dolphin fossils were found in the Radoboj Sarmatian deposits (species Delphinopsis freyeri), on the slopes of Medvednica (Platanista croatica, Delphinapterus sp. and Chamsodelphis sp.) and at the geolocality Vranić on Papuk. In the lower and middle parts of the Vranić sand quarry, numerous dolphin fossil remains are found, most commonly neck, trunk and tail vertebrae, teeth and bones of the fin skeleton (thumb, ulna and humerus bones and phalanges). Scientifically speaking, the finding of ear bones located in the area of the head of the dolphin is especially important. Based on these bones, the belonging of this dolphin to the family Kentriodontidae is more precisely determined.
SHARKS
Sharks, catsharks and rays represent a group of fish whose main characteristic is a skeleton made of cartilage (cartilaginous fish). Even though cartilaginous fish lived in the Pannonian Sea, no preserved skeletons of sharks and rays have been found in this area due to the decomposition of their skeletons over time. On the other hand, fossil remains of solid parts of the body, built of bony substances, e.g. teeth, can often be found. It is assumed that sharks and rays fed on marine mammals such as seals or smaller whales. Megalodon appeared 25 years ago and disappeared 1.5 million years ago due to a lack of food and climate change. Based on the findings of fossil teeth, it is assumed that, apart from megalodon (Otodus (Megaselachus) megalodon), some other species of sharks lived in the Pannonian Sea as well, such as Hemipristis serra, Cosmopolidus hastalis and genera Galeocerdo, Odontaspis – sand shark and Lamna – catshark.
FIN FISH
The oldest known fish fossils are 450 million years old. Naturally, fish swam in the Pannonian Sea 14 million years ago. Although the skeletons of fin fish are more often preserved, their complete findings, unlike findings of cartilaginous fish, are not so common. A skeleton of a fish was found near the Vrhovci village. However, it lacked a head, thereby preventing the determination of the fish.
CORALS
The most common fossils and findings of the builders of the reef in the Pannonian Sea are the corals. Corals (class Athozoa, lat. flower animals) belong to the phylum Cnidaria. The feed by filtering nutrients from marine suspension and their presence is an excellent indicator of the environment and climate (tropical and subtropical climate). The water temperature suitable for corals must be at least 18 °C and the sea must have complete salinity and purity. In addition, in order to survive and develop, corals require lots of light and oxygen dissolved in water.
OYSTER
An oyster is a bivalve from the family Ostreidae (real oysters) or Aviculidae (pearl oysters) that has lived in warm coastal waters of seas and oceans since the time of the Pannonian Sea. Miocene oysters were widely spread in the Pannonian Sea, therefore also in the area of today's Papuk. Fossil findings of oysters are very well preserved due to the large and massive calcite shells. The most common genera of oysters on the reefs are the following: Ostrea, Cubitostrea, Hyotissaand and Crassostrea.