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| Phoebodus saidselachus Frey, Coates, Ginter, Hairapetian, Rücklin, Jerjen & Klug, 2019 in Klug, Greif, Pohle, Ginter, Coates, Haouz, Lagnaoui, Pople et Frey, 2026. |
Phoebodus was recognized as the earliest elasmobranch known from articulated remains, a group which constitutes most modern cartilaginous fish comprising sharks, skates and rays. Its elongate body, the presence of two dorsal fins with fin spines, and the elongate head had already been described. Based on spectacularly well-preserved fossils, we add new anatomical information on its exact body proportions, the paired and caudal fins, the dermal denticles, the skull morphology, the endocast, and the gill skeleton. These new skeletons from the Famennian (Upper Devonian) of Morocco (c. 367 Ma) permit a much-improved reconstruction of the anatomy of Phoebodus. The new materials comprise the oldest elasmobranch specimens preserving the complete head in three dimensions. Additionally, the new materials yield information about growth and diet and thus position in the trophic network. Despite the newly coded characters, the phylogenetic position of the genus Phoebodus with the oldest teeth dating to the early Givetian remains that of the oldest stem-elasmobranch in the Bayesian analyses.
Key words: Chondrichthyes, Elasmobranchii, Famennian, ontogeny, exceptional preservation, Fossillagerstätten
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| Phoebodontiform elasmobranch Phoebodus saidselachus Frey et al., 2019a, middle Famennian, Upper Devonian, southern Maïder, Anti-Atlas, Morocco. A. PIMUZ A/I 5751, prep. T. Imhof, largest individual, nearly complete. B. PIMUZ A/I 5752, prep. T. Imhof, second largest individual, only caudal region missing; for details of the skull see Fig. 2. C. PIMUZ A/I 5753, prep. M. Greif, anterior half, excellent integument, fins and brachial region. D. PIMUZ A/I 5754, prep. R. Roth, two superimposed chondrichthyans; the skull in the middle is Maghriboselache mohamezanei with further remains; the straight, complete skeleton belongs to Phoebodus; the latter preserves the caudal fin. E. PIMUZ A/I 4712, holotype, smallest skeleton, nearly complete, modified after Frey et al. (2019a). |
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| Skeletal reconstruction of the phoebodontiform elasmobranch Phoebodus saidselachus Frey et al., 2019a, middle Famennian, Upper Devonian, southern Maïder, Anti-Atlas, Morocco. A. PIMUZ A/I 5754, caudalis. B, C. PIMUZ A/I 4712, posterior and anterior dorsal fins. D. PIMUZ A/I 5752, anterior dorsal fin. E. PIMUZ A/I 5751, caudalis. F, G. PIMUZ A/I 5753, pectoral fin and branchial basket. H. PIMUZ A/I 5752, head. The photos are not to scale. The scale refers only to the drawing. |
Systematic palaeontology
Chondrichthyes Huxley, 1880
Elasmobranchii Bonaparte, 1838
Phoebodontiformes Ginter et al., 2010
Genus Phoebodus St. John & Worthen, 1875
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| Reconstructions of an adult female and juvenile male of the phoebodontiform elasmobranch Phoebodus saidselachus Frey et al., 2019a, middle Famennian, Upper Devonian, southern Maïder, Anti-Atlas, Morocco. We incorporated the new anatomical details particularly in the proportions and the fin shapes. The juvenile is reconstructed after the holotype. |
Christian Klug, Merle Greif, Alexander Pohle, Michał Ginter, Michael I. Coates, Wahiba Bel Haouz, Abdelouahed Lagnaoui, Jonathan Pople, and Linda Frey. 2026. The Oldest Shark Face—Anatomy of the Devonian elasmobranch Phoebodus. Acta Palaeontologica Polonica. 71 (2), 2026: 399-430 DOI:10.4202/app.01290.2025 https://www.app.pan.pl/article/item/app012902025.html
Linda Frey, Michael Coates, Michał Ginter, Vachik Hairapetian, Martin Rücklin, Iwan Jerjen, Christian Klug. 2019. The early elasmobranch Phoebodus: phylogenetic relationships, ecomorphology and a new time-scale for shark evolution. Proc Biol Sci. 286 (1912): 20191336. DOI: doi.org/10.1098/rspb.2019.1336
