A new genus and species of fimbriid bivalve from the Kimmeridgian of the western Pontides, Turkey, and the phylogeny of the Jurassic Fimbriidae

Abstract

ABSTRACT. A new lucinoidean genus and species, Cerkesia contiae gen. et sp. nov., from the Kimmeridgian carbonate platform deposits of the C Ë erkes area (western Pontides, Turkey), is described and placed in the family Fimbriidae. Morphological comparisons reveal similarities with Fimbria, Cyclopellatia and Sphaera. A phylogenetic analysis supports the monophyly of the family. Similarities between Cerkesia and Fimbria determine inclusion of these genera in the same clade. The unusual features characterizing Cerkesia closely relate it to Cyclopellatia. Sphaera belongs to a different clade and its similarities with Cerkesia are owing to convergent and plesiomorphic characters. Cerkesia was a slow and shallow burrower. The morphology of the anterior adductor scar suggests a mode of life comparable to that of Fimbria but other features indicate adaptive strategies typical of the Lucinidae. The associated fossils and facies reveal that Cerkesia lived in soft and sandy substrates of quiet and protected areas of the carbonate platform under stressful environmental conditions. The appearance of Cerkesia in the western Pontides marks the eastward expansion of a clade that developed principally in the European seas during the Late Jurassic while the Sphaeriola-Sphaera clade was con®ned to the southernmost Tethyan margin.

Molecular phylogeny and classification of the chemosymbiotic bivalve family Lucinidae (Mollusca: Bivalvia)

“…5) Fimbria fimbriata aligns as a sister taxon to Monitilora ramsayi , Codakiinae, and Lucininae, with a late Jurassic–early Cretaceous divergence. There is a remarkable continuity of shell morphology of Fimbria ‐like species throughout the Cenozoic and Mesozoic, with bivalves possessing some characters of living Fimbria (but not necessarily congeneric) recorded back to the early Jurassic (Pliensbachian–Toarcian) (Dubar, 1948; Monari, 2003). Less certain are the even earlier fossils, for example the late Triassic Schafhaeutlia with huge cardinal teeth (Hautmann, 2001) that have been placed in Fimbriidae (e.g.…”

Sedimentology, Paleontology, and Sequence Stratigraphy of Early Permian Estuarine Deposits, South-Central New Mexico, USA

“…Taylor, Kennedy, and Hall (1973) described three aragonitic shell layers in members of superfamily Lucinoidea: a prismatic outer shell layer and middle and inner shell layers of cross-lamellar microstructure. Monari (2003) studied the shell microstructure of Cerkesia contiae Monari, 2003, an Upper Jurassic member of family Fimbriidae from Turkey, and found the same structure. (Monari, 2003).…”

“…Tethys domain: Middle Triassic: Anisian of southern China (Sha, Chen, & Qi, 1990;Komatsu, Chen, & others, 2004), southern Alps (Monari, 2003), northern Vietnam (Komatsu, Huyen, & Huu, 2010); Ladinian of Italy (Rossi Ronchetti, 1959), China (Sha, Chen, & Qi, 1990), northern Vietnam (Komatsu, Huyen, & Huu, 2010); Late Triassic: Carnian of the Alps (Italy) (Leonardi, 1943;Allasinaz, 1964Allasinaz, , 1966Gelati & Allasinaz, 1964;Fürsich & Wendt, 1977), Yugoslavia (Jurkovsek & Jelen, 1990), Slovenia (Jelen, 1988), Spain (Pérez-Valera & others, 2007); Norian of western China (H. Yao & others, 2007), Afghanistan (Polubotko, Payevskaya, & Repin, 2001); Norian-Rhaetian of Iran (Hautmann, 2001b); Rhaetian of ?Tibet (J. Yin & McRoberts, 2006), ?Hungary (Vörös, 1981).…”

Lucinidae (Bivalvia)–the most diverse group of chemosymbiotic molluscs

“…3) indicate the latter nests within the lucinids. Although at the present day there are only two living species, Fimbria ‐like bivalves were diverse and abundant during the Mesozoic (Monari, 2003). Of the other families traditionally included within the Lucinoidea, the Thyasiridae form a monophyletic group (Fig.…”