 |
Scheenstia bernissartensis (Traquair, 1911)
in Cavin, Deesri & Olive, 2019.
|
Abstract
Lepidotes bernissartensis is a species of holostean ray-finned fish from the Barremian–Aptian of Bernissart, Belgium, described by Traquair in 1911. We provide here a revision of its anatomy, which led us to include this species in the genus Scheenstia, and to consider L. brevifulcratus and L. arcuatus, both from the same site, synonymous with S. bernissartensis. We performed two cladistic analyses in order to assess the phylogenetic position of S. bernissartensis and to do an updated appraisal of the evolutionary history of the ginglymodians. Scheenstia is included in the Lepidotidae, and placed in a pectinated position between the basal genus Lepidotes and the more derived members of the family (other species of Scheenstia, Isanichthys and Camerichthys). The nodes within the lepidotids are weakly supported. Although S. bernissartensis is not directly related to S. mantelli from the Wealden of Europe, the two species have similar palaeoenvironments and stratigraphical ranges. Taken as a whole, the ginglymodians experienced several episodes of diversification that are spatially and temporally restricted. The oldest episode involved basal ginglymodians and occurred in the Middle Triassic, in marine environments along the northern margin of the Tethys. A second episode affected the Semionotidae and occurred in freshwater environments of North America and Europe in the Late Triassic and Early Jurassic. The remaining Semionotiformes, Macrosemiidae and Callipurbeckidae, ranged from the Triassic to the Early Cretaceous and were mostly marine. Among the Lepisosteiformes, two clades, the Lepidotidae and the Lepisosteoidi, show episodes of diversification, first in marine and then in freshwater environments.
Keywords: Lepisosteiformes, Lepidotidae, osteology, cladistic analysis, evolutionary history
 |
| Scheenstia bernissartensis. A–D, IRSNB P 1205, lectotype, photograph of the specimen (A) and interpretative drawing of the skull (B); photograph (C) and interpretative drawing (D) of the palate in ventral view. E, F, IRSNB P 1207, photograph of the specimen (E) and interpretative drawing of the skull (F). |
Systematic palaeontology
Holostei Muller, 1844 (sensu Grande 2010)
Ginglymodi Cope, 1872 (sensu Grande 2010)
Lepisosteiformes Hay, 1929 (sensu L opezArbarello 2012)
Lepidotidae Owen, 1860
Scheenstia López-Arbarello & Sferco, 2011
Scheenstia bernissartensis (Traquair, 1911)
Lionel Cavin, Uthumporn Deesri and Sébastien Olive. 2019. Scheenstia bernissartensis (Actinopterygii: Ginglymodi) from the Early Cretaceous of Bernissart, Belgium, with An Appraisal of Ginglymodian Evolutionary History. Journal of Systematic Palaeontology. DOI: 10.1080/14772019.2019.1634649
