1,721,200 research outputs found
FIGURE 1 in Verruca punica, a new species of verrucomorph barnacle (Crustacea, Cirripedia, Thoracica) from the Lower Danian (Palaeocene) of Tunisia
No full textFIGURE 1. Location of the El Haria section, near El Kef (northwest Tunisia), the provenance of the types of Verruca punica Buckeridge & Jagt, sp. nov.Published as part of Buckeridge, John S., Jagt, John W. M. & Speijer, Robert P., 2008, Verruca punica, a new species of verrucomorph barnacle (Crustacea, Cirripedia, Thoracica) from the Lower Danian (Palaeocene) of Tunisia, pp. 37-46 in Zootaxa 1844 on page 40, DOI: 10.5281/zenodo.18325
Thoracica Darwin 1854
No full textSuperorder Thoracica Darwin, 1854 Remarks. Buckeridge & Newman (2006) have recently revised the systematics of the Thoracica, and proposed four very distinct orders. Within the Sessilia, the suborder Verrucomorpha was demonstrated to have had a scalpelliform ancestor, arising from this order via the Brachylepadomorpha Withers, 1923 during the Middle to Late Jurassic.Published as part of Buckeridge, John S., Jagt, John W. M. & Speijer, Robert P., 2008, Verruca punica, a new species of verrucomorph barnacle (Crustacea, Cirripedia, Thoracica) from the Lower Danian (Palaeocene) of Tunisia, pp. 37-46 in Zootaxa 1844 on page 38, DOI: 10.5281/zenodo.18325
Verrucidae Darwin 1854
No full textFamily Verrucidae Darwin, 1854 Diagnosis. Wall asymmetric, comprising four immovable dissimilar calcareous plates: carina, rostrum, scutum and tergum; second scutum and tergum together form a movable operculum; basis membranous or calcareous. Remarks. In addition to the Verrucidae, the Verrucomorpha comprises two other families, the earliest of which, the Proverrucidae Newman, 1989 (Newman and Hessler, 1989), (Cenomanian-Upper Maastrichtian), is characterised by the presence of extra (lateral) plates in the shell wall, and the extant Neoverrucidae Newman in Newman & Hessler, 1989, which is a true ‘link’ with early non-verrucomorph barnacles, as it retains several basal whorls of imbricating plates, demonstrating phyletic proximity to a scalpelliform ancestor (Newman, 2000; Buckeridge & Newman, 2006).Published as part of Buckeridge, John S., Jagt, John W. M. & Speijer, Robert P., 2008, Verruca punica, a new species of verrucomorph barnacle (Crustacea, Cirripedia, Thoracica) from the Lower Danian (Palaeocene) of Tunisia, pp. 37-46 in Zootaxa 1844 on page 39, DOI: 10.5281/zenodo.18325
Qianshanosuchus Boerman & Perrichon & Yang & Li & Martin & Speijer & Smith 2023, GEN. NOV.
No full textQIANSHANOSUCHUS GEN. NOV. Zoobank registration: urn:lsid:zoobank.org:act: 52FA1082-28AB-4246-8385-C8AC77C4746D Etymology: ‘ Qianshano -’ after Qianshan Basin, where the only specimen was discovered; ‘- suchus ’ after ‘soukhos’, an Ancient Greek word for crocodile. Type species: Qianshanosuchus youngi gen. & sp. nov.Published as part of Boerman, Sophie A., Perrichon, Gwendal, Yang, Jian, Li, Cheng-Sen, Martin, Jeremy E., Speijer, Robert P. & Smith, Thierry, 2023, A juvenile skull from the early Palaeocene of China extends the appearance of crocodyloids in Asia back by 15 - 20 million years, pp. 787-811 in Zoological Journal of the Linnean Society 197 on page 791, DOI: 10.1093/zoolinnean/zlac067, http://zenodo.org/record/769603
Shelf ecosystems along the U.S. Atlantic coastal plain prior to and during the Paleocene‐Eocene thermal maximum: Insights Into the stratigraphic architecture
No full textThe Paleocene-Eocene Thermal Maximum (PETM) is the most pronounced global warming event of the early Paleogene related to atmospheric CO
2 increases. It is characterized by negative δ
18O and δ
13C excursions recorded in sedimentary archives and a transient disruption of the marine biosphere. Sites from the U.S. Atlantic Coastal Plain show an additional small, but distinct δ
13C excursion below the onset of the PETM, coined the “pre-onset excursion” (POE), mimicking the PETM-forced environmental perturbations. This study focuses on the South Dover Bridge core in Maryland, where the Paleocene-Eocene transition is stratigraphically constrained by calcareous nannoplankton and stable isotope data, and in which the POE is well-expressed. The site was situated in a middle neritic marine shelf setting near a major outflow of the paleo-Potomac River system. We generated high-resolution benthic foraminiferal assemblage, stable isotope, trace-metal, grain-size and clay mineralogy data. The resulting stratigraphic subdivision of this Paleocene-Eocene transition is placed within a depth transect across the paleoshelf, highlighting that the PETM sequence is relatively expanded. The geochemical records provide detailed insights into the paleoenvironment, developing from a well-oxygenated water column in latest Paleocene to a PETM-ecosystem under severe biotic stress-conditions, with shifts in food supply and temperature, and under dysoxic bottom waters in a more river-dominated setting. Environmental changes started in the latest Paleocene and culminated atthe onset of the PETM, hinting to an intensifying trigger rather than to an instantaneous event at the Paleocene-Eocene boundary toppling the global system.
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Figure 5 in A juvenile skull from the early Palaeocene of China extends the appearance of crocodyloids in Asia back by 15-20 million years
No full textFigure 5. Skull of Qianshanosuchus youngi gen. & sp. nov. (IBCAS QS15), photograph (A) and interpretative drawing (B) in occipital view. Abbreviations: ex, exoccipital; fm, foramen magnum; fr, frontal; j, jugal; par, parietal; po, postorbital; q, quadrate; qj, quadratojugal; soc, supraoccipital; soc-par groove, medial groove on the supraoccipital and parietal; sq, squamosal; sq ridge, ridge on the lateral edge of the squamosal. Scale bar: 1 cm.Published as part of Boerman, Sophie A., Perrichon, Gwendal, Yang, Jian, Li, Cheng-Sen, Martin, Jeremy E., Speijer, Robert P. & Smith, Thierry, 2023, A juvenile skull from the early Palaeocene of China extends the appearance of crocodyloids in Asia back by 15-20 million years, pp. 787-811 in Zoological Journal of the Linnean Society 197 on page 795, DOI: 10.1093/zoolinnean/zlac067, http://zenodo.org/record/769603
Figure 12 in A juvenile skull from the early Palaeocene of China extends the appearance of crocodyloids in Asia back by 15-20 million years
No full textFigure 12. Comparison of the snout in ventral view among crocodyloids and alligatoroids. A, Qianshanosuchus youngi gen. & sp. nov. (IBCAS QS15). B, Asiatosuchus depressifrons (IRSNB R251). C, Dongnanosuchus hsui (DM000001-F000001, adapted from Shan et al., 2021). D, juvenile specimen of Crocodylus niloticus (IRSNB 4618, digitally reversed). E, juvenile specimen of Alligator mississippiensis (IRSNB 3480, digitally reversed). Abbreviations: fpm, foramen on the premaxillary– maxillary suture; fV, foramen for cranial nerve V. Scale bars: 1 cm.Published as part of Boerman, Sophie A., Perrichon, Gwendal, Yang, Jian, Li, Cheng-Sen, Martin, Jeremy E., Speijer, Robert P. & Smith, Thierry, 2023, A juvenile skull from the early Palaeocene of China extends the appearance of crocodyloids in Asia back by 15-20 million years, pp. 787-811 in Zoological Journal of the Linnean Society 197 on page 806, DOI: 10.1093/zoolinnean/zlac067, http://zenodo.org/record/769603
Figure 6 in A juvenile skull from the early Palaeocene of China extends the appearance of crocodyloids in Asia back by 15-20 million years
No full textFigure 6. Mandible of Qianshanosuchus youngi gen. & sp. nov. (IBCAS QS15), photographs (A, C, E, G) and interpretative drawings (B, D, F, H) in dorsal view (A, B), ventral view (C, D), labial view (E, F) and lingual view (G, H). Abbreviations: an, angular; ar, articular; emf, external mandibular fenestra; fic, foramen intermandibularis caudalis; glf, glenoid fossa; sur, surangular; sur ridge, ridge on the lateral surface of the surangular. Scale bar: 1 cm.Published as part of Boerman, Sophie A., Perrichon, Gwendal, Yang, Jian, Li, Cheng-Sen, Martin, Jeremy E., Speijer, Robert P. & Smith, Thierry, 2023, A juvenile skull from the early Palaeocene of China extends the appearance of crocodyloids in Asia back by 15-20 million years, pp. 787-811 in Zoological Journal of the Linnean Society 197 on page 795, DOI: 10.1093/zoolinnean/zlac067, http://zenodo.org/record/769603
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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