Migom f (3 risultati)
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Da: ConchBooks, Harxheim, GermaniaConchBooks
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EUR 34,50
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Aggiungi al carrelloThe dentitions of the extant species Heterodontus mexicanus Taylor & Castro-Aguirre, 1972 and Heterodontus quoyi (Frémenville, 1840) (Elasmobranchii, Chondrichthyes) is studied, clarifying all intraspecific and interspecific characteristics for these two species, thus forming a base in the understanding of francisci-type dentiti…ons. Dignathic heterodonty was observed in H. mexicanus. 32 pp., 4 plates, 8 color & 8 b/w figs, br. 4.
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Da: ConchBooks, Harxheim, GermaniaConchBooks
Contatta il venditoreVenditore con 4 stelleCondizione: Usato
EUR 46,00
EUR 24,00 spedizioneSpedito da Germania a U.S.A.Quantità: 1 disponibili
Aggiungi al carrelloType material of the four nominal Palaeocene-Eocene species of Heterodontus from the North Sea Basin, H.?lerichei Casier, 1943b, Heterodontus vincenti (Leriche, 1905), Heterodontus wardenensis Casier, 1966 and Heterodontus woodwardi Casier, 1946 is restudied, based on a very detailed analysis of H.?vincenti specimens recovered f…rom the Ypresian of Egem (Belgium) and on morphological, stratigraphical and environmental considerations and on intraspecific and interspecific conclusions from a study on the extant species Heterodontus mexicanus Taylor & Castro-Aguirre, 1972 and Heterodontus quoyi (Frémenville, 1840) (see Migom & Hoedemakers, 2023). This led to the realization that several of the above fossil species represent, in fact, different ontogenetic stages of the same species. In this work, a specimen from the original type series of H.?vincenti is formally designated as lectotype and other specimens are designated as paralectotypes. Dignathic and gynandric heterodonty is observed in H.?vincenti and interspecific heterodonty with this species is demonstrated through a comparison with the above Recent species. A partial overview of the ontogenetic characteristics of the Palaeocene H.?lerichei is presented. Heterodontus adneti nov. sp. is defined for specimens formerly described as Heterodontus cf. vincenti, sensu Adnet (2006). Figured specimens in Adnet (2006) are designated as holotype and paratype. Other putative Heterodontus species are identified from literature but I refrain from formally describing them as these specimens were not studied. Finally, a new set of characteristics, based amongst others on interspecific differences with the above-mentioned extant species, is suggested to identify H.?vincenti and H.?lerichei. München. Verlag Friedrich Pfeil. 60 pp., 7 plates, 7 color & 7 b/w figs, 1 tab, paperback 4 [29.7 x 21 cm].
Altre immagini- Brossura
Da: ConchBooks, Harxheim, GermaniaConchBooks
Contatta il venditoreVenditore con 4 stelleCondizione: Usato
EUR 46,00
EUR 24,00 spedizioneSpedito da Germania a U.S.A.Quantità: 1 disponibili
Aggiungi al carrelloFossil teeth from 13 chondrichthyan species spread over the Hexanchiformes, Squaliformes, Squatiniformes, Heterodontiformes and Orectolobiformes orders are displayed and for most a morphological analysis provides a correct determination on the tooth category. The recovered fossils consist of mainly marine specimen like isolated…teeth, vertebrae, tooth plates, spines, invertebrates and even land based plant remains. Finds from land mammals and reptiles, and birds were very rare. The extinct species Squalus smithi Herman, 1982b is redefined as a synonym for Squalus minor Daimeries, 1888, the validity of Squatina crassa Daimeries, 1889 is reinstated and the occurrence of Heterodontus in the North Sea basin during the Eocene is revised to one single species (see Migom & Hoedemakers in prep.). Future volumes will comprise studies on other elasmobranchii and holocephali. München. Dr. Friedrich Pfeil. 55 pp., 20 plates, 13 color & 2 b/w figs, 1 tab, paperback 4 [29.7 x 21 cm].
