Rare myodocopid ostracods from Mesozoic sections of Hungary: summary, revision and description of new taxa

Abstract

With the exception of polycopids, Mesozoic myodocopid ostracods are regarded as uncommon in the fossil record. They are known from a few localities in the Tethys, and most of them are considered to be pelagic forms. However, a relatively rich and taxonomically diverse material is derived from Hungarian sections; these represent various formations deposited during the Triassic to Cretaceous.The aim of this study is to summarize the current knowledge of Mesozoic myodocopids and to provide new information concerning their classification and phylogenetic relations. This includes new occurrences of Triassic entomozoid Schallreuterizoe groosae Kozur, 2004, cylindroleberidid Triadocypris sp., cypridinid Palaeocypridina tulceaensis Sebe, 2013, Jurassic thaumatocyprid Pokornyopsis cf. bettenstaedti (Bartenstein, 1949) and P. feifeli (Triebel, 1941). The revision of the holotype of gigantic Triassic Triadogigantocypris balatonica Monostori, 1991 give new results concerning the valve structure and taxonomic position of the genus. Two new genera (Neorichterina n. gen. and Hungaroleberis n. gen.) and four new species (Neorichterina striata n. sp., Pokornyopsis csurgokutensis n. sp., Hungaroleberis retiferus n. sp. and Palaeocypridina goeroegae n. sp.) of the subclass Myodocopa are described. Moreover, most of the Albian to Cenomanian representatives of "Conchoecia" are newly classified as Entomozoidae (Neorichterina n. gen.), which allows to extend the range of the family up to the Cretaceous. A summary of the relevant assemblages present in Hungary will help to complement the existing, previously published literature on myodocopids, and also clarify details about the phylogenetic model of the group.

Rhaetian (Late Triassic) ostracods (Crustacea, Ostracoda) from the offshore prolongation of the North Dobrogean Orogen into the Romanian Black Sea shelf

“…This would rather indicate that Pokornyopsis did not colonize crevicular systems in the Triassic. Hungaroleberis has been reported from the Wordian, Middle Permian, of Greece (Crasquin-Soleau & Baud 1998) to the Bajocian, Middle Jurassic, of Hungary (Tóth & Cséfán 2018), and the species reported in this paper (Fig. 13G-L) correspond to its first known occurrence in the Triassic worldwide.…”

“…The Triassic myodocopid fossil record from the North Dobrogea is rich compared to that of contemporaneous assemblages (e.g., Crasquin-Soleau & Grădinaru 1996;Sebe et al 2013;Forel & Grădinaru 2018). Until the present record, the thaumatocyprid Pokornyopsis was only known from the Jurassic (e.g., Triebel 1941;Bartenstein 1949;Aubrecht & Kozur 1995;Tóth & Cséfán 2018). Kozur (1974) and Aubrecht & Kozur (1995) mentioned the occurrence of specimens of Pokornyopsis in the late Triassic, but these were not further discussed or illustrated and Tóth & Csefan (2018) revealed that the specimens were lost.…”

“…from the Early to Late Jurassic (seeTóth & Cséfán 2018 for a summary) is characterized by having strongly reticulate valves with parallel ribs surrounded by 3 concentric marginal ribs. Pokornyopsis sp.…”

Bounded by crises: An overview of the evolution of marine ostracods during the Triassic

“…For each time slice, localities that provided less than 3 genera are not considered as their paucity may bias the analysis, with an exception for Dienerian and Smithian that we tentatively characterize in spite of their extreme low diversity. Nekto-benthic taxa are excluded (Crasquin-Soleau and Grădinaru, 1996;Sebe et al, 2013;Forel and Grădinaru, 2018;Tóth & Cséfán, 2018). For each stage we follow the method used by Forel and Grădinaru (2018) and produced a similarity symmetric matrix, following Q-mode analysis (Supplementary File 2; e.g., Henderson and Heron, 1976;Pielou, 1979;Janson and Vegelius, 1981;Digby and Kempton, 1987).…”

Kora-Kréta (Albai) Őskörnyezeti Rekonstrukció Dunántúli-Középhegységi Rétegsorok Sekélytengeri És Édesvízi Kagylósrák Együtteseinek Változásai Alapján

“…Célom volt még a bentosz fauna leírása mellett a medence-képződményekből előkerült ritka Myodocopa együttes leírása és értékelése is (Cséfán & Tóth 2013;Tóth & Cséfán 2018).…”