Romaleodelphis pollerspoecki was a dolphin-like toothed whale related to the ancestors of both modern oceanic dolphins and beaked whales, living in coastal waters covering what is now Austria during the early Miocene about 22 million years ago.
Although only known from a single fossil skull, this cetacean was probably around 3m long (~9’10”). It had a long snout lined with over 100 small pointed uniformly-shaped teeth, and the bony walls of its inner ears were well-preserved enough to show that it was able to hear narrow-band high frequency sounds – a specific form of echolocation that has convergently evolved multiple times in various modern and extinct toothed whale lineages.
Based on the presence of ancient river-mouth deposits in the area where Romaleodelphis was found, it may potentially have been capable of traversing between marine, brackish, and freshwater environments similar to the modern franciscana.
References:
- Bavarian State Collections of Natural History. “‘Astonishing Results’ – Scientists Reveal Secrets of Mysterious 22-Million-Year-Old Dolphin Skull.” SciTechDaily, 15 Nov. 2024, https://scitechdaily.com/astonishing-results-scientists-reveal-secrets-of-mysterious-22-million-year-old-dolphin-skull/
- Sanchez-Posada, Catalina, et al. “Romaleodelphis pollerspoecki, gen. et sp. nov., an archaic dolphin from the Central Paratethys (Early Miocene, Austria).” Journal of Vertebrate Paleontology (2024): e2401503. https://doi.org/10.1080/02724634.2024.2401503
- Wikipedia contributors. “Romaleodelphis” Wikipedia, 06 Nov. 2024, https://en.wikipedia.org/wiki/Romaleodelphis