Abstract
The genus Bucculentum Schweitzer & Feldmann, 2009 is exceptional among the brachyuran decapods in having the augenrest dorsally inclined. Hitherto, the genus comprised two species, both from European Upper Jurassic localities; here, further two species are described, Bucculentum horstkuscheli, n. sp. and B. plettenbergense, n. sp., which differ in their proportions of the carapace regions and especially in their shapes of the augenrest. A newly described feature shared by all congeneric species is the groove extending from the centre of the dorsal portion of the augenrest and terminating towards the cervical groove. The function of this groove could have been to lead the water stream out from the augenrest to cleanse impurities from the muddy sea bottom, where these crabs are supposed to have lived.
References
Bakel, B.W.M. van, Fraaije, R.H.B., Jagt, J.W.M. & Artal, P. (2008) An unexpected diversity of Late Jurassic hermit crabs (Crustacea, Decapoda, Anomura) in Central Europe. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 250, 137–156. https://doi.org/10.1127/0077-7749/2008/0250-0137
Collins, J.S.H. & Wierzbowski, A. (1985) Crabs from the Oxfordian sponge megafacies of Poland. Acta Geologica Polonica, 35, 73–88.
Crônier, C. & Boursicot, P.-Y. (2009) A new Decapod Crustacean faunule from the Middle Jurassic of north-west France. Palaeontology, 52, 1275–1289. https://doi.org/10.1111/j.1475-4983.2009.00896.x
Fraaije, R.H.B., Schweigert, G. & Van Bakel, B.W.M. (2017) New Late Jurassic (Kimmeridgian) paguroids (Crustacea: Decapoda: Anomura) from the Swabian Alb, southern Germany. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 285 (1), 117–121. https://doi.org/10.1127/njgpa/2017/0673
Głowniak, E. (2002) The ammonites of the family Perisphinctidae from the Plicatilis Zone (lower Middle Oxfordian) of the Polish Jura Chain (Central Poland); their taxonomy, phylogeny and biostratigraphy. Acta Geologica Polonica, 52, 307–364.
Głowniak, E. (2006) Correlation of the zonal schemes at the Middle-Upper Oxfordian (Jurassic) boundary in the Submediterranean Province: Poland and Switzerland. Acta Geologica Polonica, 56, 33–50.
Jantschke, H. & Schweigert, G. (2020) The semimammatum and semiarmatum ammonite biohorizons (Late Oxfordium, Hypselum Zone) in the Upper Jurassic of SW Germany. Palaeodiversity, 13, 89–130. https://doi.org/10.18476/pale.v13.a9
Latreille, P.A. (1802–1803) Histoire naturelle, générale et particuliére, des crustacés et des insects. Vol. 3. Dufart, Paris, 468 pp,
Linnaeus, C.V. (1758) Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Vol.1. 10th Edition. Laurentii Slavii, Stockholm, 824 pp. https://doi.org/10.5962/bhl.title.542
Ostrowski, S. (2005) Autocyclic development of Oxfordian sponge-microbial bioherms from Central and Southern Poland. Volumina Jurassica, 3, 45–53. [in Polish with English Abstract]
Risso, A. (1816) Histoire Naturelle des Crustacés des Environs de Nice. Librairie Grecque-Latine-Allemande, Paris, 175 pp., 3 pls. https://doi.org/10.5962/bhl.title.8992
Schairer, G. & Yamani, S.-A. (1982) Die Schwammkalke von Biburg bei Weißenburg/Bayern (Oberoxford, Südliche Frankenalb). Allgemeine Übersicht. Mitteilungen der Bayerischen Staatssammlung für Paläontologie und historische Geologie, 22, 9–17.
Schneider, S., Harzhauser, M., Kroh, A., Lukeneder, A. & Zuschin, M. (2013) Ernstbrunn Limestone and Klentnice Beds (Kimmeridgian-Berriasian; Waschberg-Ždánice Unit; NE Austria and SE Czech Republic). State of the art and bibliography. Bulletin of Geosciences, 88, 105–130. https://doi.org/10.3140/bull.geosci.1360
Schweitzer, C.E. & Feldmann, R.M. (2009) Revision of some Prosopinae sensu Glaessner, 1969 (Crustacea: Decapoda: Brachyura) including four new families, four new genera, and five new species. Annalen des Naturhistorischen Museums in Wien, 110, 55–121.
Schweigert, G. & Callomon, J.H. (1997) Der bauhini-Faunenhorizont und seine Bedeutung für die Korrelation zwischen tethyalem und subborealem Oberjura. Stuttgarter Beiträge zur Naturkunde (B), 247, 1–69.
Starzyk, N., Krzemińska, E. & Krzemiński, W. (2011) Intraspecific variation in the Jurassic crab Bucculentum bucculentum (Decapoda: Homolodromioidea: Bucculentidae). Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 260 (2), 203–210. https://doi.org/10.1127/0077-7749/2011/0169
Wehner, G. (1988) Über die Prosopiden (Crustacea, Decapoda) des Jura. Inaugural-Dissertation zur Erlangung des Doktorgrades der Fakultät für Geowissenschaften der Ludwig-Maximilians-Universität zu München, München, 154 pp.
Ziegler, B. (1959) Profile aus dem Weißen Jura delta der Schwäbischen Alb. Arbeiten aus dem Geologisch-Paläontologischen Institut der Technischen Hochschule Stuttgart, Neue Folge, 21, 1–70.