Search results for "Cephalopoda"
showing 10 items of 13 documents
Distribution of late Maastrichtian pachydiscid and scaphitid ammonites in the Maastricht and Kunrade formations of the southeast Netherlands
2018
Abstract The pachydiscid Pachydiscus ( Pachydiscus ) gollevillensis (d'Orbigny, 1850), long held to be confined to the ‘Kunrade Limestone’ (nowadays Kunrade Formation) in the eastern part of southern Limburg (Kunrade–Benzenrade area, the Netherlands), is now recorded from the basal Nekum Member (Maastricht Formation) at the ENCI-HeidelbergCement Group quarry, Sint-Pietersberg (Maastricht). Here we review the stratigraphic distribution of pachydiscid and scaphitid ammonites in outcrops west of the River Maas (Maastricht Formation) and in the Kunrade–Benzenrade area (Kunrade Formation). The latter unit has been correlated with part of the Lanaye Member (Gulpen Formation) up to the basal Emael…
Allometric space and allometric disparity: a developmental perspective in the macroevolutionary analysis of morphological disparity.
2008
8 pages; International audience; Here, we advance novel uses of allometric spaces--multidimensional spaces specifically defined by allometric coefficients--with the goal of investigating the focal role of development in shaping the evolution of morphological disparity. From their examination, operational measures of allometric disparity can be derived, complementing standard signals of morphological disparity through an intuitive and process-oriented refinement of established analytical protocols used in disparity studies. Allometric spaces thereby become a promising context to reveal different patterns of evolutionary developmental changes and to assess their relative prevalence and import…
Survey on the presence of A. simplex s.s. and A. pegreffii hybrid forms in Central-Western Mediterranean Sea
2016
Abstract In this study, 1029 fish and cephalopod samples came from Central-Western Mediterranean (FAO 37.1.1 and FAO 37.1.3) were analysed for Anisakidae larvae research with the aim to identify possible hybridisations between Anisakis pegreffii and Anisakis simplex s.s. species. A total of 1765 larvae were detected, with prevalence values between 8.1% and 100%. The morphologic analysis revealed characters attributable to morphotype I of Anisakis in 98.5% of the examined larvae, while 1.5% belonged to the morphotype II. PCR-based Restriction Fragment Length Polymorphism (PCR–RFLP) analysis of the entire ITS region (ITS1, 5.8S and ITS2) of nuclear ribosomal DNA (rDNA) was performed with Hinf…
First record of the enigmatic coleoid genus Longibelus from Sakhalin (Far East Russia): a contribution to our understanding of Cretaceous coleoid hab…
2021
AbstractA newly collected specimen of the enigmatic coleoid genus Longibelus is recorded from lower Turonian strata along the River Shadrinka in Sakhalin (Russian Far East). To date, this is the first record of Late Cretaceous coleoid cephalopods from the island and, in fact, from the entire Pacific coast of the Russian Federation. Lithological characteristics, coupled with published geochemical analyses (δ13C and Corg content), suggest the habitat of this coleoid taxon to have been the middle to outer (i.e. distal) shelf. Its provenance from the stratigraphical level that is known as the Scaphites Event, characterised by a mass occurrence of Scaphites and Yesoites, may be indicative of occ…
Deep-Time Phylogenetic Clustering of Extinctions in an Evolutionarily Dynamic Clade (Early Jurassic Ammonites)
2012
7 pages; International audience; Conservation biologists and palaeontologists are increasingly investigating the phylogenetic distribution of extinctions and its evolutionary consequences. However, the dearth of palaeontological studies on that subject and the lack of methodological consensus hamper our understanding of that major evolutionary phenomenon. Here we address this issue by (i) reviewing the approaches used to quantify the phylogenetic selectivity of extinctions and extinction risks; (ii) investigating with a high-resolution dataset whether extinctions and survivals were phylogenetically clustered among early Pliensbachian (Early Jurassic) ammonites; (iii) exploring the phylogene…
Mollusca. Tetrabranchiata. Palaeontologische Wandtafeln XIX.
1879
Uzskates līdzeklis - sienas plakāts - paleontoloģijas mācībām. Fosīlo un recento galvkāju čaulu uzbūve. Uz plakāta LU Ģeoloģijas institūta zīmogs un inventāra numurs. Plakāta lielums 148 x 116 cm, tas veidots no 4 litogrāfijām - tipogrāfijā apdrukātām papīra loksnēm, kas pielīmētas pie lina auduma, ar koka līstēm augšā un apakšā. Pie augšējās līstes piestiprinātas auklas: viena plakāta pakāršanai demonstrācijas laikā un 2 lentas apsaitēšanai, kad tas satīts rullī. Otrā pusē lieliem burtiem plakāta nosaukums, kas lasāms, kad plakāts sarullēts.
Mollusca. Tetrabranchiata : Palaeontologische Wandtafeln XXVII
1909
Uzskates līdzeklis - sienas plakāts - paleontoloģijas mācībām. Fosīlo galvkāju čaulu morfoloģija, uzbūve. Uz plakāta LU Ģeoloģijas institūta zīmogs un inventāra numurs. Plakāta lielums 148 x 116 cm, plakāts veidots no 4 litogrāfijām - tipogrāfijā apdrukātām papīra loksnēm, kas pielīmētas pie lina auduma, ar koka līstēm augšā un apakšā. Pie augšējās līstes piestiprinātas auklas: viena plakāta pakāršanai demonstrācijas laikā un 2 lentas apsaitēšanai, kad tas satīts rullī. Otrā pusē lieliem burtiem plakāta nosaukums, kas lasāms, kad plakāts sarullēts.
Mollusca. Tetrabranchiata : Palaeontologische Wandtafeln LXXIX
1909
Uzskates līdzeklis - sienas plakāts - paleontoloģijas mācībām. Fosīlo galvkāju čaulu uzbūve. Uz plakāta LU Ģeoloģijas institūta zīmogs un inventāra numurs. Plakāta lielums 148 x 116 cm, plakāts veidots no 4 litogrāfijām - tipogrāfijā apdrukātām papīra loksnēm, kas pielīmētas pie lina auduma, ar koka līstēm augšā un apakšā. Pie augšējās līstes piestiprinātas auklas: viena plakāta pakāršanai demonstrācijas laikā un 2 lentas apsaitēšanai, kad tas satīts rullī. Otrā pusē lieliem burtiem plakāta nosaukums, kas lasāms, kad plakāts sarullēts.
Mollusca. Cephalopoda. Schalenbau : Palaeontologische Wandtafeln LXXVIII
1909
Uzskates līdzeklis - sienas plakāts - paleontoloģijas mācībām. Fosīlo galvkāju čaulu morfoloģija, uzbūve. Uz plakāta LU Ģeoloģijas institūta zīmogs un inventāra numurs. Plakāta lielums 148 x 116 cm, plakāts veidots no 4 litogrāfijām - tipogrāfijā apdrukātām papīra loksnēm, kas pielīmētas pie lina auduma, ar koka līstēm augšā un apakšā. Pie augšējās līstes piestiprinātas auklas: viena plakāta pakāršanai demonstrācijas laikā un 2 lentas apsaitēšanai, kad tas satīts rullī. Otrā pusē lieliem burtiem plakāta nosaukums, kas lasāms, kad plakāts sarullēts.
Assessing divergence time of Spirulida and Sepiida (Cephalopoda) based on hemocyanin sequences
2011
Abstract The phylogenetic position of the mesopelagic decabrachian cephalopod Spirula is still a matter of debate. Since hemocyanin has successfully been used to calibrate a molecular clock for many molluscan species, a molecular clock was calculated based on this gene with special attention to the cephalopod genera Spirula and Sepia. The obtained partial sequence comprising ca., one third (3567 bp) of the complete gene is similar to that of Sepia officinalis. The molecular clock was calibrated using the splits of Gastropoda–Cephalopoda (ca. 550 ± 50 mya) and Heterobranchia–Vetigastropoda (ca. 380 ± 10 mya). The resulting hemocyanin-based molecular clock is stable, and the estimated diverge…