29 research outputs found

    A small fossil fish fauna, rich in Chlamydoselachus teeth, from the Late Pliocene of Tuscany (Siena, central Italy)

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    A small elasmobranch teeth and teleost otolith assemblage from the Piacenzian-earliest Gelasian of Tuscany (Castelnuovo Berardenga Scalo, Siena province, Italy) is described. The exceptional abundance of teeth belonging to Cizlamydoselaclms lawleyi Davis, 1887 has enabled us to better define and confirm the validity of this doubtful fossil taxon.ln agreement with Davis (1887) and Ffeil ( 1983) this species appears lo differ from the living frilled shark C. anguìneus Garman, 1884 at least by its larger size. Palaeoecological inferences based on the ecology of C. anguineus together with deep water sharks such as Cellfrophorus granulosus (Bloch & Schneider, 1801) and the teleost otolith assemblage mainly characterised by macrourids and myctophids enable us to configure, in the Pìacenzian to earlìest Gelasian of Tuscany (Siena subbasin of the Siena-Radicofani Basin) an upper bathyal slope palaeoenvironment. The occurrence of Chlamydoselaclms in the Piacenzian-earliest Gelasian ofthe Mediterranean palaeo-area demonstrates the persistence of an oceanic environment not as profusely developed as during the early Zanclean (i.e. lower part of MPL 2 foraminiferal biozone; see Cigala Fulgosi, 1986, 1996)

    Ontogenetic vertebral growth patterns in the basking shark Cetorhinus maximus.

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    Age and growth of the basking shark Cetorhinus maximus (Gunnerus) was examined using vertebral samples from 13 females (261 to 856 cm total length [TL]), 16 males (311 to 840 cm TL) and 11 specimens of unknown sex (376 to 853 cm TL). Vertebral samples were obtained worldwide from museums and institutional and private collections. Examination of multiple vertebrae from along the vertebral column of 10 specimens indica led that vertebral morphology and band pair (alternating opaque and translucent bands) counts changed dramatically along an individual column. Smaller sharks had similar band pair counts along the length of the vertebral column while large sharks had a difference of up to 24 band pairs between the highest and lowest count along the column. Our evidence indicates that band pair deposition may be related to growth and not time in this species and thus the basking shark cannot be directly aged using vertebral band pair counts
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