Electric Rays, Torpediniformes, which get their name from their ability to produce bioelectricity, used to both capture prey and deter predators, with some species said to be capable of producing a shock equivalent to dropping a hairdryer into a bathtub. They are highly distinctive with a rounded disk and a flattened muscular tail; Electric Rays are poor swimmers, but lacking any natural enemies, this is not usually an issue. Based upon their relationships to other Rays, they are assumed to have first appeared during the Cretaceous, though fossil Electric Rays are only known from post-Cretaceous deposits. As with other Chondrichthyans (Sharks and Rays) almost all fossil Electric Rays are known from isolated teeth only, due to a cartilagenous skeleton with limited preservational potential, and a habit of shedding teeth throughout their lives. However, one species is known from several full body specimens, Titanonarke molini, from the Early Eocene Bolca Lagerstätte of Verona Province in northeast Italy.
In a paper published in the Journal of Systematic Palaeontology on 22 September 2017, Giuseppe Marramà of the Department of Palaeontology at the University of Vienna, Kerin Claeson of the Philadelphia College of Osteopathic Medicine, Giorgio Carnevale of the Dipartimento di Scienze della Terra at the Universit a degli Studi di Torino, and Jürgen Kriwet, also of the Department of Palaeontology at the University of Vienna, describe a second species of Titanonarke, also from the Bolca Lagerstätte.
The new species is named Titanonarke megapterygia, meaning 'large-fins'. The species is described from a specimen (MCSNV IG.135576) previously assigned to Titanonarke molini, but adjudged to be a separate species following a review of all the material assigned to the genus. The species is described from an almost complete, articulated, specimen 626.2 mm in length. It differs considerably from the original species, due to a much lower number of pre-caudal (non-tail) vertebrae - 74 compared to over 100 in Titanonarke molini - which greatly alters the body proportions of Titanonarke megapterygia.
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In a paper published in the Journal of Systematic Palaeontology on 22 September 2017, Giuseppe Marramà of the Department of Palaeontology at the University of Vienna, Kerin Claeson of the Philadelphia College of Osteopathic Medicine, Giorgio Carnevale of the Dipartimento di Scienze della Terra at the Universit a degli Studi di Torino, and Jürgen Kriwet, also of the Department of Palaeontology at the University of Vienna, describe a second species of Titanonarke, also from the Bolca Lagerstätte.
The new species is named Titanonarke megapterygia, meaning 'large-fins'. The species is described from a specimen (MCSNV IG.135576) previously assigned to Titanonarke molini, but adjudged to be a separate species following a review of all the material assigned to the genus. The species is described from an almost complete, articulated, specimen 626.2 mm in length. It differs considerably from the original species, due to a much lower number of pre-caudal (non-tail) vertebrae - 74 compared to over 100 in Titanonarke molini - which greatly alters the body proportions of Titanonarke megapterygia.
Titanonarke megapterygia from the Eocene Monte Postale site. (A) MCSNV IG.135576; (B) detail of the head and hyoid apparatus. Abbreviations: ao, antorbital cartilage; cb, ceratobranchials; hym, hyomandibula; me, Meckel’s cartilage; nc, nasal capsule; pq, palatoquadrate; sca, scapulocoracoid; syn, synarcual; rf, rostral fontanelle; ro, rostral cartilage. Scale bars are 50 mm. Marramà (2017).
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