The marine arthropods from the Solnhofen Lithographic Limestones (Late Jurassic, Germany) in the collections of the Muséum national d'Histoire naturelle, Paris

ABSTRACT The palaeontological collections of the Muséum national d'Histoire naturelle, Paris, France, house a broad range of marine arthropods from the Solnhofen Lithographic Limestones (Late Jurassic, Germany). These arthropods include decapod crustaceans, stomatopods, supposed mysidaceans, and limulids. A commented systematic list is proposed in order to give to the specialists an instrument of comparison and reference.


INTRODUCTION
The palaeontological collections of the Muséum national d'Histoire naturelle, Paris, house a number of specimens of marine arthropods from the Solnhofen Lithographic Limestones (Bavaria, Germany) including decapod crustaceans, stomatopods, mysidaceans, and limulids. The Solnhofen collection is composed of several generations of material added over the last 250 years. This collection was mainly derived from specimens accumulated by scientific changes between the Paris Muséum and different German museums and institutions. Other material was also collected by the French Revolutionary armies and during the Napoleonic wars. Moreover, a group of specimens was traded in the late 19 th century to different fossil sellers. The scientific changes were supported by some very important French professors such as Barthélemy Faujas de Saint-Fond (1741-1819), Anselme-Gaétan Desmarest (1781-1838), Alexandre Brongniart (1770-1847) and above all Alphonse Milne Edwards . Other specimens came from changes with other museums (e.g., Manchester Museum) and donations by fortunate collectors (e.g., Boué, de Roissy, de Drée, du Mouy, Stuer) that sometimes collaborated with the Paris Muséum professors. Sometimes, fossil specimens were traded to some famous sellers such as Émile Deyrolle (Paris, 46 rue du Bac, since 1831), Louis Saemann (Paris, between 1850 and 1866), Meyrat (Basel, Comptoir Géologique à Birsfelden), Grebel, Wendler &Company (Geneva, Comptoir Minéralogique et Géologique Suisse, between 1905 andc. 1917), Jean Danhauser (Paris, Comptoir Minéralogique et Géologique, 51 rue de Seine, between 1832 and 1836) and Dr. F. Krantz (Bonn, Rheinisches Mineralien-Kontor GmbH & Co. KG, since 1833).
The "Konservat-Lagerstätte of Solnhofen" is well known since the beginning of the 18 th century and it is still subject of interest by the specialists of the world. Therefore, the aim of the present study is to propose a commented list of the marine arthropods from the Solnhofen Lithographic Limestones housed in the Paris Muséum. Indeed, several specimens housed in old collections in the Paris Muséum, are rather well preserved and totally unknown to date. After their taxonomic identification, we have decided to illustrate some of these specimens in order to give to the specialists an instrument of comparison and reference.

ColleCtion arrangement
The history of the palaeontological collections housed in the Paris Museum is complicated because these collections are the heritage of different arrangements from the Royal Cabinet of Natural History to the public collections of the new Muséum of Natural History in 1793. In this time, the department of palaeontology did not exist at the Paris Muséum and fossils were distributed into different collections: geology, botany, mineralogy. In 1853, when the chair of palaeontology was especially created for Alcide d'Orbigny, numerous professors of the Museum refused to give him their fossils to constitute a new palaeontological collection (Brygoo 2002;Vénec-Peyré 2002). This conflicting situation explains the dispersion of the fossils into the Paris Museum. For instance, the type specimens of Eryon cuvieri Desmarest, 1817, were forgotten in a drawer of the geological collection during almost two centuries and recently rediscovered by one of the authors (S. Charbonnier). Today, this situation is quite solved but there are always numerous fossils housed in the geological collection. Consequently, this study includes specimens housed into different buildings having at the same time different catalogue numbers.

Fossil loCalities
As reported by Garassino & Schweigert (2006), the lithographic limestones of the Late Jurassic in southern Germany (Bavaria) comprise a large set of localities usually summarized under the name "Solnhofen". The study of the Paris collections has allowed identifying mainly three localities: Solnhofen, Eichstätt and Pappenheim. However, the specimens reported as discovered in Pappenheim are probably from other locality. Indeed, the town of Pappenheim is located in the valley of the Altmühl River, 5 km north of the outcrop area of the Solnhofen Lithographic Limestones, and probably these specimens were purchased there from some local persons (Günter Schweigert pers. comm. 2011). Following the last geological setting by Schweigert (2007)

Penaeidae
In conclusion, each identified species is listed, as follows: the specimen number, collecting locality, collector (when known), and comment. The type species is given also for each taxon.

Comments
The figured specimen is relatively poorly preserved and is assigned to A. tipularius with doubt because several diagnostic characters have probably remained on the counter plate which is not in the collection. Note that one other species of this genus -A. elegans Münster, 1839 -is known from the Solnhofen Lithographic Limestones but is not present in the Paris collection.

Comments
The figured specimen (MNHN.F.R03502) is remarkably long (total length: 26 cm) and corresponds probably to an exuvia because its cephalothorax is dislocated. The same disarticulation is observed on the specimen MNHN.F.A42004 (Fig. 2B).

Comments
The figured specimen is very probably an exuvia. The preservation is typical for some limestones from Solnhofen and especially for this species, which is Rauna angusta Münster, 1839, because of the carapace with a longitudinal crest near the dorsal line.

Comments
Two species of Palinurina are known at present in the Solnhofen Lithographic Limestones, P. longipes and P. tenera Oppel, 1862. The studied specimens have been assigned to the type species for the strongly tuberculate pereiopods and carapace (smooth pereiopods in P. tenera in which the carapace is not preserved).

Comments
The lack of dorsal carinae on the cephalothorax and the smooth frontal margin allows ascribing the specimen to C. orbiculatus. This species is relatively rare in the Solnhofen Lithographic Limestones (see Garassino & Schweigert 2006  useful information about the Solnhofen Lithographic Limestones. We really thank Marie-Astrid Angel (Bibliothèque de Paléontologie, MNHN) and Sophie Guillon (Bibliothèque de Géologie, MNHN) for their useful historical researches and also Christian Lemzaouda (Département Histoire de la Terre, MNHN) for assistance in photographic work. We also thank Jean-Claude Gall and Annemarie Ohler for their reviews. This paper is a contribution from the Museo di Storia Naturale di Milano (Paleontology Department), and the UMR CNRS 7207 Centre de Recherche sur la Paléobiodiversité et les Paléoenvironnements as well as the Département Histoire de la Terre (MNHN, Paris).