Berriasian (Early Cretaceous) oyster Pycnogryphaea weberae from Crimea is one of the earliest known pycnodonteine oysters. Examination of shell morphology and microstructure of this species shows that it shares characters of the subfamilies Gryphaeinae and Pycnodonteinae. Shell microstructure of Pycnogryphaea weberae lacks vesicular structure and is similar to microstructure of the genus Gryphaea. At the same time the shell of this species possesses morphological characters typical of pycnodonteins: development of chomata and well-defined circumferential curb. Pycnogryphaea weberae is regarded as a transitional taxon between the subfamilies Gryphaeinae and Pycnodonteinae and referred herein to a new genus Pycnogryphaea within the Pycnodonteinae. This suggests that the subfamily Pycnodonteinae likely originated from the Late Jurassic representatives of the genus Gryphaea (Gryphaeinae) in Berriassian. First pycnodonteins preserved shell microstructure of the genus Gryphaea but developed chomata along all the perimeter of both valves.
Arkadiev, V.V., Grishchenko, V.A., Guzhikov, A.Y., Manikin, A.G., Savelieva, Y.N., Feodorova, A.A., and Shurekova, O.V. 2017a. Ammonites and magnetostratigraphy of the Berriasian–Valanginian boundary deposits from eastern Crimea. Geologica Carpathica 68: 505–516.
Arkadiev, V., Guzhikov, A., Baraboshkin, E., Savelieva, J., Feodorova, A., Shurekova, O., Platonov, E., Manikin, A. 2017b. Biostratigraphy and magnetostratigraphy of the upper Tithonian–Berriasian of the Crimean Mountains. Cretaceous Research [published online, doi: 10.1016/j.cretres.2017.07.011].
Aqrabawi, M. 1993. Oysters (Bivalvia, Pteriomorphia) of the Upper Cretaceous rocks in Jordan. Palaeontology, stratigraphy and comparison with the Upper Cretaceous oysters of Nortwest Europe. Mitteilungen aus dem Geologisch-Paläontologischen Institut der Universität Hamburg 75: 1–135.
Bogdanova, T.N. 1980. New Early Cretaceous oysters of Mangyshlak [in Russian]. In: G.A. Stukalina (ed.), Novye vidy drevnih rastenij i bespozvonočnyh SSSR. Vol. 5, 26–28. Nauka, Moskva.
Boss, K.J. 1982. Mollusca. In: S.P. Parker (ed.), Synopsis and Classification of Living Organisms. Vol. 1, 945–1166. McGraw-Hill, New York.
Carter, J.G. 1990. Shell microstructural data for the Bivalvia. Part IV. Order Ostreoida. In: J.G. Carter (ed.), Skeletal Biomineralization: Patterns, Processes and Evolutionary Trends. Vol. 1, 347–362. Van Nostrand Reinhold, New York.
Carter, J.G., Harries, P.J., Malchus, N., Sartori, A.F., Anderson, L.C., Bieler, R., Bogan, A.E., Coan, E.V., Cope, J.C.W., Cragg, S.M., GarciaMarch, J.R., Hylleberg, J., Kelley, P., Kleemann, K., K K., J., McRoberts, C., Mikkelsen, P.M., Pojeta, J. Jr., Temkin, I., Yancey, T., and Zieritz, A. 2012. Illustrated Glossary of the Bivalvia. Part N, Revised, Volume 1. Treatise Online 48: 1–209.
Cooper, M.R. 1992. Pycnodonteine oysters from the Upper Cretaceous of Zululand. Durban Museum Novitates 17: 23–57.
Férussac, A.E.J.A. de 1821–1822. Tableaux Systèmatiques des Animaux Mollusques suivis d’un Prodrome Général pour tous les Mollusques Terrestres ou Fluviatiles Vivants ou Fossiles. Première Partie, Tableaux Systématiques Généraux. 114 pp. Arthus-Bertrand, Paris.
Fisher de Waldheim, G. 1835. Lettre à M. le Baron de Férussac sur quel ques genres de coquilles du Muséum Demidoff et en particulier sur quelques fossils de la Crimée. Bulletin de la Société Impériale des Naturalistes de Moscou 8: 99–123.
Frau, C., Bulot, L.G., and Wimbledon, W.A.P. 2015. Upper Tithonian Himalayitidae Spath, 1925 (Perisphinctoidea, Ammonitina) from le Chouet (Drôme, France): implications for the systematics. Geologica Carpathica 66: 117–132.
Grobben, C. 1894. Zur Kenntniss der Morphologie, der Verwandtschaftsverhältnisse und des Systems der Mollusken. Kaiserliche Akademie der Wissenschaften (Mathematisch-Naturwissenschaftlichen Classe), Sitzungs berichte 103 (1): 61–86.
Hammer, O., Harper, D.A.T., and Ryan, P.D. 2001. PAST: Paleontological Statistics software package for education and data analysis. Palaeontologia Electronica 4 (1): 1–9.
Harry, H.W. 1985. Synopsis of the supraspecific classification of living oysters (Bivalvia: Gryphaeidae and Ostreidae). The Veliger 28: 121–158.
Ivanov, A.V. 1995. New taxa of the suborder Exogyrina (Ostreoida, Bivalvia) [in Russian]. Paleontologičeskij žurnal 3: 26–36.
Koppka, J. 2015. Revision of the Bivalvia from the Upper Jurassic Reu chenette Formation, Northwest Switzerland—Ostreoidea. Zootaxa 3927: 1–117.
Kosenko, I.N. 2017. Late Jurassic–Early Cretaceous oysters from Siberia: A systematic review. Acta Palaeontologica Polonica 62: 759–778.
Lamarck, J.B. de 1801. Systéme des animaux sans vertébres, ou table général des classes, des orders et des genres de ces animaux. 432 pp. Deterville, Paris.
Lamarck, J.-B. de 1806. Mémoires sur les fossiles des environs de Paris. Explication des planches relatives aux coquilles fossiles des environs de Paris. Annales du Muséum d’Histoire Naturelle 8: 156–166.
Linnaeus, C. 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Editio decima. 824 pp. Laurentius Salvius, Holmiae.
Machalski, M. 1988. Redescription of a Danian oyster Pycnodonte simile (Pusch, 1837) from Poland. Acta Palaeontologica Polonica 33: 73–83.
Malchus, N. 1990. Revision der Kreide-Austern (Bivalvia, Pteriomorphia) Ägyptens (Biostratigraphie, Systematik). Berliner Geowissenschaftliche Abhandlungen, Reiche A 125: 1–231.
Malchus, N. 1998. Multiple parallel evolution and phylogenetic significance of shell chambers and chomata in the Ostreoidea (Bivalvia). In: P.A. Johnston and J.W. Haggart (eds.), Bivalves: an Eon of Evolution, 393–407. University of Calgary Press, Calgary.
Marwick, J. 1931. The Tertiary Mollusca of the Gisborne District. New Zealand Geological Survey, Paleontological Bulletin 13: 1–177.
Pusch, G.G. 1837. Polens Paläontologie: oder, Abbildung und Beschreibung der vorzüglichsten und der noch unbeschriebenen Petrefakten aus den Gebirgsformationen in Polen, Volhynien und den Karpathen nebst einigen allgemeinen Beiträgen zur Petrefaktenkunde und einem Versuch zur Vervollständigung der Geschechte des europäischen AuerOchsen. 214 pp. Schweizerbart’s Verlagshandlung, Stuttgart.
Rafinesque, C.S. 1815. Analyse de la nature ou tableau de l’Université et des corps organisés, etc. 223 pp. Jean Barravecchia, Palermo.
Reboulet, S., Szives, O., Aguirre-Urreta, B., Barragán, R., Company, M., Idakieva, V., Ivanov, M., Kakabadze, M.V., Moreno-Bedmar, J.A., Sandoval., J., Baraboshkin E.Y., Çağlar, M.K., Fözy, I., González- Arreola, C., Kenjo, S., Lukeneder, A., Raisossadat, S.N., Rawson, P.F., and Tavera, J.M. 2014. Report on the 5th International Meeting of the IUGS Lower Cretaceous Ammonite Working Group, the Kilian Group (Ankara, Turkey, 31st August 2013). Cretaceous Research 50: 126–137.
Rousseau, L. 1842. Description des principaux fossiles de la Crimée. In: A. de Démidoff (ed.), Voyage dans la Russie méridionale et la Crimée. Tome 2, 781–823. Ernest Bourdin, Paris.
Stanton, T.W. 1893. The Colorado formation and its invertebrate fauna. Bulletin of the United States Geological Survey 106: 1–288.
Stenzel, H.B. 1959. Cretaceous oysters of southwestern North America. In: International Geological Congress, XX Session, Mexico City, 1956, El Sistema Cretácico 1: 15–37.
Stenzel, H.B. 1971. Oysters. In: R.C. Moore (ed.), Treatise on Invertabrate Paleontology (N) Mollusca 6, Bivalvia 3, N953–N1224. University of Kansas, Lawrence and Geological Society of America, Boulder.
Tschelzova, N.A. [Čeltsova, N.A.] 1969. Značenie mikrostruktury rakoviny melovyh ustric dlâ ih sistematiki. 83 pp. Nauka, Moskva.
Vialov, O.S. 1936. On the classification of the oysters [in Russian]. Doklady Akademii Nauk SSSR 4 (1): 2–5.
Vialov, O.S. 1945. New oysters from the Paleogene of the Trans-Caspian region [in Russian]. Doklady Akademii Nauk SSSR 48 (3): 200–203.
Vialov, O.S. 1983. General classification of oysters [in Ukrainian]. Doklady Аkademii Nauk Ukrainskoj SSR, Seriâ B 11: 6–8.