A strange ‘rock’ fished in Azorean waters revealed to be a 6 million years old beaked whale fossil

The extinct beaked whale fossil is now exposed at the Porto Pim Whale Factory Porto museum, Faial, Azores.


We are used to say that the Ocean is full of surprises, and here in the Azores this is particularly true! It happens that in the Autumn of 2017 a fishing vessel encountered something weird while recovering the nets over the Banco Açor, something that the fishermen described as ‘looking like a rock with a metallic sound and approximately shaped as a dolphin cranium’.

The ‘rock’ was delivered to the Oceanography and Fisheries Department of the University of Azores and, thanks to the help of paleontologists, was identified as part of the cranium of Tusciziphius atlanticus, a species of beaked whale that inhabited Azorean waters between 3.6 and 7.3 millions of years ago. Yes, you read well, these cetaceans were roaming around in our waters when most of Azores islands were…not even islands!


A fossil from Tusciziphius atlanticus recovered off the Iberian Peninsula coast. Only a few of these fossils have ever been found, four near the Atlantic Coast of Spain and one off the coast of United States (Biannucci et al., 2013)


But how did these cetaceans look like? Hard to tell precisely, when other parts of their bodies have never been found, most likely scavenged by sharks and tube worms specialized in digesting whale’s bone tissue. However, using similarities in the cranium features, paleontologists hypothesized they were close in appearance with the only remnant species of Ziphius genre, the Cuvier’s Beaked Whale (Ziphius cavirostris), but smaller in size (~3.7 meters) and with bizarre cranial bulges (visible in the picture above). T. atlanticus was most likely a deep diving species, like other beaked whales of modern time.


Cuvier’s Beaked Whale (Ziphius cavirostris).  Adults can reach 7 meters in length and retains the record for the longest and deepest mammal dive! If you wish to know more about this species, check our previous blog post HERE! Illustration by Uko Gorter. Source: Source: Encyclopedia of Marine Mammals IIIrd Ed. Bernd Würsig, I. G. M. Thewissen & KIT M. Kovacs.

Lorenzo Fiori

About Lorenzo Fiori

Lorenzo is Main Guide and Technical & Scientific Director at TERRA AZUL. He is originally from Italy, holds a PhD about behavioral responses of humpback whales to swim-with-whales tourism activities in Tonga.

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