Boletín de la Sociedad Geológica Mexicana Volumen 75, núm. 2, A220323, 2023 http://dx.doi.org/10.18268/BSGM2023v75n2a220323

Fossil relatives of extant parasitic crustaceans from the Mesozoic of Europe

Parientes fósiles de parásitos actuales de crustáceos, del Mesozoico de Europa

Mario Schädel^1,*, Christina Nagler², Matúš Hyžný³

¹ Institute of Evolution and Ecology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany.

² Zoomorphology group, Department of Biology II, Ludwig-Maximilians-Universität München, Großhaderner Straße 2, 82152 Planegg-Martinsried, Germany.

³ Department of Geology and Paleontology, Comenius University in Bratislava, Mlynská dolina, Ilkovičova 6, 842 15 Bratislava, Slovakia.

* Corresponding author: (M. Schädel) This email address is being protected from spambots. You need JavaScript enabled to view it.

How to cite this article:

Schädel, M., Nagler, C., Hyžný, M., 2023, Fossil relatives of extant parasitic crustaceans from the Mesozoic of Europe: Boletín de la Sociedad Geológica Mexicana, 75 (2), A220323. http://dx.doi.org/10.18268/BSGM2023v75n2a220323

Manuscript received: January 1, 2023; Corrected manuscript received: March 16, 2023; Manuscript accepted: March 21, 2023.

ABSTRACT

The fossil record of Isopoda includes remains of presumed parasites. Among the fossils which have been discussed as potential parasites are those termed as Urda Münster, 1840. Some of these fossils have been discussed as possibly related to an extant group of parasites, Gnathiidae Leach, 1814. The type species of Urda – Urda rostrata Münster, 1840 – is herein interpreted as a close relative of the group Gnathiidae, based on the shared occurrence of a number of apomorphic features. This is with Urda punctata (Münster, 1842) herein being interpreted as a junior subjective synonym of U. rostrata. However, not all of the fossils associated with the name Urda can safely be identified as close relatives of Gnathiidae. Moreover, it is unclear whether the extinct species, which can be identified as close relatives of U. rostrata and Gnathiidae form a monophyletic group, as we could not identify an autapomorphy for a natural group Urda. A new species of close relatives of Urda rostrata and Gnathiidae – Urda buechneri n. sp. – is formally described based on µCT image data. Palaega suevica Reiff, 1936 and Palaega kessleri Reiff, 1936 are found to be subjective synonyms and are re-interpreted as Urda suevica n. comb. – a species closely related to U. rostrata. Due to the documented destruction of the holotype, a herein figured fossil specimen is designated as the neotype of Urda suevica. Palaega? stemmerbergensis Malzahn, 1968 is also interpreted as a close representative of U. rostrata and herein treated as Urda stemmerbergensis n. comb. Another already formally described species – Eobooralana rhodanica gen. et comb. nov. – is interpreted as a more distant relative, which is likely to be closer related to other extant species of Isopoda than those within Gnathiidae. For three species there are not enough characters preserved to interpret them as closely related to U. rostrata and Gnathiidae: Urda? liasica Frentzen, 1937 nom. dub. (type material destroyed, description insufficient for proper diagnosis), Urda? moravica Remeš, 1912 and Urda? zelandica Buckeridge and Johns, 1996.

Keywords: Isopoda, Urda, Gnathiidae, parasitism, mouthparts.