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Thuy, Numberger-Thuy & Pineda-Enríquez, 2021 DOI: 10.1098/rsos.210643 |
Abstract
Understanding of the evolutionary history of the ophiuroids, or brittle stars, is hampered by a patchy knowledge of the fossil record. Especially, the stem members of the living clades are poorly known, resulting in blurry concepts of the early clade evolution and imprecise estimates of divergence ages. Here, we describe new ophiuroid fossil from the Lower Jurassic of France, Luxembourg and Austria and introduce the new taxa Ophiogojira labadiei gen. et sp. nov. from lower Pliensbachian shallow sublittoral deposits, Ophiogojira andreui gen. et sp. nov. from lower Toarcian shallow sublittoral deposits and Ophioduplantiera noctiluca gen. et sp. nov. from late Sinemurian to lower Pliensbachian bathyal deposits. A Bayesian morphological phylogenetic analysis shows that Ophiogojira holds a basal position within the order Ophiurida, whereas Ophioduplantiera has a more crownward position within the ophiurid family Ophiuridae. The position of Ophioduplantiera in the evolutionary tree suggests that family-level divergences within the Ophiurida must have occurred before the late Sinemurian, and that ancient slope environments played an important role in fostering early clade evolution.
Keywords: Echinodermata, ophiuroids, deep sea, phylogeny, evolution
Systematic palaeontology
Class Ophiuroidea Gray, 1840
Subclass Myophiuroidea Matsumoto, 1915
Infraclass Metophiurida Matsumoto, 1913 (crown-group of Ophiuroidea)
Superorder Euryophiurida O'Hara et al. (2017)
Order Ophiurida Müller & Troschel (1840)
Suborder Ophiurina Müller & Troschel, 1840 sensu O'Hara et al. [5]
Family unknown
Genus Ophiogojira gen. nov.
Etymology: Genus named in honour of French metal band Gojira, for producing songs of an unfathomable intensity, beautifully dark and heavy, and exploring the abyss of life and death, of human strength and error, and of thriving and yet threatened oceans.
Ophiogojira labadiei sp. nov.
Etymology: Species named after Jean-Michel Labadie, bass player of French metal band Gojira.
Holotype: MnhnL OPH159
Type locality and stratum: succession of clays and thin lumachellic beds with siderite nodules, dated to the late Early Pliensbachian (Davoei chronozone, Early Jurassic), near Sedan, Ardennes, France.
Ophiogojira andreui sp. nov.
Etymology: Species named after Christian Andreu, guitar player of French metal band Gojira.
Holotype: MnhnL OPH167
Type locality and stratum: dark grey marls, Ottempt Member of the Aubange Formation, earliest Toarcian (Tenuicostatum chronozone, Early Jurassic), Uerschterhaff near Sanem, Luxembourg.
Family Ophiuridae Müller & Troschel, 1840
Genus Ophioduplantiera gen. nov.
Etymology: Genus named after Joseph (Joe) and Mario Duplantier of French metal band Gojira, to honour their inspiring artistic achievements and their authentic, compassionate personalities.
Ophioduplantiera noctiluca sp. nov.
Etymology: Species name formed from Latin ‘noctiluca’, literally translating into ‘night light’, in reference to the bioluminescent dinoflagellate genus Noctiluca, commonly called ‘sea sparkle’, because the name-bearing ophiuroid species brings light into the dark origins of the Ophiuridae.
Holotype: MnhnL OPH170
Type locality and stratum: marls from the Kehlbach and Scheck Members within the Adnet Formation, late Sinemurian to late Pliensbachian (Raricostatum to Margaritatus chronozones, Early Jurassic), Glasenbach Gorge near Salzburg, Austria.
Ben Thuy, Lea D. Numberger-Thuy and Tania Pineda-Enríquez. 2021. New Fossils of Jurassic Ophiurid Brittle Stars (Ophiuroidea; Ophiurida) provide evidence for early Clade Evolution in the Deep Sea. Proceedings of the Royal Society B. DOI: 10.1098/rsos.210643
