Palaeomacrosemius thiollieri, gen. et sp. nov., a new Macrosemiidae (Neopterygii) from the Upper Jurassic of the Solnhofen Archipelago (Germany) and Cerin (France), with a revision of the genus Macrosemius

ABSTRACT

We describe Palaeomacrosemius thiollieri, gen. et sp. nov., a new genus of Macrosemiidae (Neopterygii: Ginglymodi), from the Upper Jurassic (late Kimmeridgian to early Tithonian) of the Solnhofen Archipelago (Germany) and Cerin (France). Palaeomacrosemius, gen. nov., is characterized primarily by the following features: presence of vertical scale rows that do not dichotomize dorsal to the lateral line (unlike members of the genus Macrosemius Agassiz); a long dorsal fin with 32–33 dorsal fin rays; and a smaller scale-free area immediately ventrolateral to the dorsal fin compared with Macrosemius. Small, hook-like spines located on the posterolateral border of the principal dorsal fin rays may have functioned in reproductive behavior. We also review the currently known species of Macrosemius (M. rostratus Agassiz and M. fourneti Thiollière) from the Upper Jurassic plattenkalk of southern Germany and Cerin, France. Macrosemius rostratus, which we here restrict to the German plattenkalk basins of Eichstätt and Solnhofen (Tithonian above the eigeltingense horizon), is mainly characterized by the presence of 37–39 dorsal fin rays, which are very long in adult specimens. Macrosemius fourneti is mainly characterized by the presence of 34–35 dorsal fin rays, which are broader in the posterior part of the fin. Although M. fourneti was previously known only from Cerin, France, we here describe it for the first time from the older plattenkalk of Brunn (southern Germany, late Kimmeridgian).

Citation for this article: Ebert, M., J. A. Lane, and M. Kölbl-Ebert. 2016. Palaeomacrosemius thiollieri, gen. et sp. nov., a new Macrosemiidae (Neopterygii) from the Upper Jurassic of the Solnhofen Archipelago (Germany) and Cerin (France), with a revision of the genus Macrosemius. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2016.1196081.

http://zoobank.org/urn:lsid:zoobank.org:pub:414EFC70-C0FC-4CE7-919C-20ACB28A709D

ACKNOWLEDGMENTS

We would like to thank G. Bergér (MBH), D. Berthet and D. Besson (MHNL), R. Brocke (SMF), G. Clément (MNHN), A. Prieur and E. Robert (FSL), M. Richter and Z. Johanson (NHMUK), M. Riley (CAM SM), O. Rauhut, A. López-Arbarello, and M. Moser (BSPG), M. Röper (Museum Solnhofen), S. Walsh (RSM), M. Wilmsen (MMG-SNSD), and F. Witzmann (MB) for permission to study material housed at their institutions. We are indebted to the following colleagues for providing digital photographs of important specimens in their care: D. Berthet (MHNL; for MHNL 20015229: Palaeomacrosemius thiollieri, gen. et sp. nov., MHNL 20015232: Histionotus falcani, and MHNL 20015242: Notagogus inimontis), T. Bürgin (Naturmuseum St. Gallen; for Legnonotus cf. krambergeri), J. Cripps and P. Snelgrove (Dorset County Museum; for Histionotus angularis G.325), B. Ekrt (NMP; for the holotype of Macrosemius rostratus, previously published only as a drawing by Agassiz, 1844), K. González-Rodriguez (for photos of Macrosemiocotzus), A. Henrici (CMNH; for CMNH 4453 and CMNH 4765), and M. Mäuser (NKMB; for Macrosemius sp. nov. 1: NKMB P 2009-Watt 67 and NKMB P2009-Watt 379). Special thanks to J. Clarke (Oxford University) for his photographs of MCZ specimens, and to U. Eller (Dümpelsfeld) for excellent preparation of MHNL 200150746, an important specimen of Macrosemius fourneti. We also thank the editor and reviewers. Funding for this project was provided by Volkswagen Foundation grant I/84 636.