Jurassic brachyurans of the genus Bucculentum Author Krzemińska, Ewa Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Poland Author Starzyk, Natalia 0000-0003-2785-6661 Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Poland & https: // orcid. org / 0000 - 0003 - 2785 - 6661 Author Fraaije, René H. B. 0000-0002-3465-1093 Oertijdmuseum, The Netherlands. https: // orcid. org / 0000 - 0002 - 3465 - 1093 Author Schweigert, Günter 0000-0003-3798-8609 Staatliches Museum für Naturkunde Stuttgart, Germany. https: // orcid. org / 0000 - 0003 - 3798 - 8609 Author Lukeneder, Alexander 0000-0002-8384-3366 Natural History Museum of Vienna, Austria. https: // orcid. org / 0000 - 0002 - 8384 - 3366 text Zootaxa 2021 2021-09-08 5032 3 395 410 journal article 10.11646/zootaxa.5032.3.5 1175-5326 5497036 321FAB6F-EEF4-4273-A2EA-C5EDFD08611F Genus Bucculentum , key to the species 1. Metabranchial region nearly as wide as hepatic region; epibranchial region only c. 1/3 as wide as hepatic region........................................................................................ B. plettenbergense , n. sp. - metabranchial region narrower than hepatic region......................................................... 2. 2. Augenrest vertical to long body axis or almost so (dorsal view)............................................... 3. - augenrest oblique, aligned with proximal portions of hepatic regions.......................... B. horstkuscheli , n. sp. 3. Suborbital spur divided; in frontal view augenrest is close to dorsal side of carapace ( Fig. 1D ) and flanked with several small tubercles................................................................................ B. bachmayeri . - suborbital spur undivided; in frontal view augenrest is close to ventral side of carapace ( Fig. 1B ) and flanked laterally with one elongated protuberance.................................................................... B. bucculentum .