Super hearing and 102 teeth: 22-million-year old Ur-dolphin fossil reveals unique abilities

An ancient dolphin fossil discovered in Austria revealed remarkable high-frequency hearing abilities, similar to those of modern dolphins. A group of researchers led by paleontologist Gertrude Rössner has described a previously unknown prehistoric species of dolphins. The fossil was found in 1980 in the area of the city of Linz, when private collector Jürgen Pollerspöck stumbled upon bones of a prehistoric animal, which were later handed over to the Bavarian State Collection for Paleontology and Geology in Munich.

Only the not quite complete skull of the dolphin has been preserved, which has an elongated snout and 102 uniform teeth. The dolphin skull is strongly compressed, making the examination of its anatomy particularly difficult. Using a computed tomography scanner, researchers conducted an anatomical reconstruction of the inner ear, indicating that Romaleodelphis pollerspoecki could hear high-frequency signals. The anatomical reconstruction of the inner ear of the fossil provided remarkable results, revealing its unique auditory abilities.

According to a recent detailed analysis, the primitive dolphin likely had excellent hearing ability in the high-frequency range, similar to that of modern dolphins. The representatives of this species possessed unique auditory abilities. Romaleodelphis pollerspoecki is one of the oldest known toothed whales that possessed a sense of hearing similar to that found today in porpoises, indicating advanced auditory capabilities. Analyses of the remains showed that Romaleodelphis pollerspoecki belongs to the group of toothed whales but differs significantly from all previously known primitive representatives.

Researchers from the Bavarian State Collection of Paleontology and Geology and Ludwig Maximilian University of Munich determined that Romaleodelphis pollerspoecki belongs to a new genus previously unknown to science and is related to the Chilcacetus line. Romaleodelphis pollerspoecki is likely related to the now-extinct, very primitive dolphins of the so-called Chilcacetus lineage, as comparisons with other fossil dolphins support this connection. All previous fossils of the Chilcacetus lineage come from the northeastern Pacific and the coasts of South America. Therefore, the discovery of Romaleodelphis pollerspoecki in Europe surprised scientists.

According to first author Catalina Sánchez Posada from Ludwig Maximilians University Munich, the discovery of Romaleodelphis pollerspoecki may provide important new information about the origin and evolution in the earliest Miocene. The results of Sánchez Posada's team will be presented in the "Journal of Vertebrate Paleontology." The analysis of fossil remains showed that the ancient dolphin lived about 22 million years ago in the coastal part of the Miocene Paratethys Sea, in the territory of modern Austria.

The Paratethys Sea was a shallow inland sea that extended north from the newly formed Alps and was home to many organisms, including various single-celled organisms, algae, clams, snails, cephalopod relatives, and fish. Using high-frequency signals has a special advantage for dolphins: they can communicate in a frequency range that is outside the hearing ability of their predators. Dolphins, including Romaleodelphis pollerspoecki, can communicate in frequency ranges that are outside the hearing ability of their predators, providing a clear survival advantage. Modern dolphins also hear high-frequency sounds well.

The new species was named Romaleodelphis pollerspoecki after its discoverer, Jürgen Pollerspöck. According to the information, the fossil was already found in 1980 by Jürgen Pollerspöck. The remains were received by the Bavarian State Collection for Paleontology and Geology in Munich.

When the ancient dolphin died, remains were preserved. A 22 million-year-old skeleton showed a research team that the animal differed significantly from other toothed whales and was particularly good at hearing high frequencies, similar to modern dolphins. Using a computed tomography scanner, researchers conducted an anatomical reconstruction of the inner ear, indicating that Romaleodelphis pollerspoecki could hear high-frequency signals. The representatives of this species possessed unique auditory abilities.

Romaleodelphis pollerspoecki is one of the oldest known toothed whales with advanced auditory capabilities. The anatomical reconstruction of the inner ear of the fossil provided remarkable results, revealing its unique auditory abilities. The discovery of this new species may provide important new information about the origin and evolution in the earliest Miocene.

Sources: Süddeutsche Zeitung, Die Welt, Sat.1, Die Zeit, Der Standard - Archäologie, Rossiyskaya Gazeta

This article was written in collaboration with generative AI company Alchemiq