But what does Thom Yorke have to do with a race that lived millions of years ago? Nothing, but evidently the researchers at the University of Turin like good rock
The fossil under study was uncovered in December 2020 at the renowned paleontological site of Bolca (Monti Lessini, Verona) during recent excavations conducted by the Museo di Civico di Storia Naturale di Verona. Known since the 16th century, Bolca is one of the world’s most famous paleontological sites for the abundance, diversity, and exceptional preservation of its fossils, especially fish.
These fossils document the existence of an ancient shallow tropical sea associated with coral reefs about 50 million years ago, in an era known as the Eocene, where the Monti Lessini stand today. Due to their paleontological significance, the fossil deposits of Bolca, along with other paleontological sites in the Val d’Alpone, have recently been added to the list of Italian sites nominated to become a UNESCO World Heritage Site.
An exceptional discovery for its evolutionary significance.
The study, recently published in the prestigious scientific journal Palaeontology, is authored by an Italo-Austrian team led by paleontologists Giuseppe Marramà and Giorgio Carnevale, a researcher and professor, respectively, from the Department of Earth Sciences at the University of Turin.
Dr. Roberto Zorzin, a geologist and curator of the museum who supervised the excavations and co-authored the study, explains:
From the initial analyses, it was clear that we were dealing with an exceptional specimen, not only due to its completeness and the quality of its preservation but also because of its evolutionary significance.
The fossil under study is a beautifully preserved fossil ray representing a new species belonging to the myliobatiformes, a highly diversified group of rays today represented by stingrays, eagle rays, and mantas. These are known for a peculiar characteristic: the presence of one or more venomous stingers on the tail, used as a defense mechanism against other predatory fish and occasionally against humans.
These rays can be categorized into two very distinct groups, both morphologically and ecologically: the superfamily Dasyatoidea includes benthic and non-durophagous rays like stingrays and pastinaches, which, having a discoidal pectoral disk with poorly mineralized rays, swim in an undulatory manner and live primarily on the seabed. With batteries of small and numerous teeth with a bilobed root, they capture soft-bodied prey, mainly polychaete worms, small fish, and crustaceans. In contrast, rays from the Myliobatoidea superfamily, like eagle rays and mantas, are pelagic or bentopelagic, meaning they live in the open sea.
This is enabled by their pectoral fins shaped like wings, supported by robust, mineralized rays, allowing for an oscillatory type of swimming, akin to “underwater flight” in the water column. They also possess cephalic lobes, projections of the pectoral fins located anterior to the head, used to locate and unearth prey. Some of these pelagic rays, like eagle rays, are durophagous, meaning they have few, large, and robust teeth with multiple roots with which they crush the hard shells of mollusks and crustaceans they feed on, while others like mantas feed on plankton.
Professor Giorgio Carnevale highlights:
“The presence of two ecomorphotypes that are so different today, without intermediate forms, makes it difficult to define how and from whom the durophagous pelagic rays originated, as until now we did not have fossil transition forms that could clarify this aspect.”
The Missing Link
The study of this new fossil ray has not only allowed for the reconstruction of its appearance, diet, and way of life but also has established that it represents a sort of “missing link,” or rather, a transitional form between the more primitive non-durophagous benthic rays and the more derived durophagous pelagic rays. This fossil ray indeed possesses a mix of characteristics common to both groups of rays: like stingrays and pastinaches, it had small lateral teeth with a bilobed root and poorly mineralized pectoral fin rays, while like eagle rays, it possessed wing-shaped pectoral fins, cephalic lobes, and a row of central teeth with multiple roots.
A Tribute to the Radiohead Singer
This combination of features allowed Dasyomyliobatis thomyorkei (a name inspired by Thom Yorke, the leader of Radiohead) to transition from undulatory to oscillatory swimming, enabling this ray to exploit the wide range of habitats offered by the ancient tropical sea of Bolca, from the heterogeneous shallow marine environment to the open sea. It also allowed the ray to feed on a wide variety of prey, from soft-bodied to more robustly shelled.
