The “Stanford ranking” (SR) of standardized citation indicators calculates an individual scientist’s composite c-score, addressing limitations of the h-index. Updated annually, the SR lists the top 100,000 scientists and the top 2% in each specialty. This study examines all (500) palaeontologists included in the SR (SR-palaeontologists), comparing their h-index, c-score and related productivity and citation variables. Analyses cover geographical distribution, statistical characterization and relationships among variables. SR-palaeontologists are concentrated mainly in North America and central-northern Europe. An average SR-palaeontologist has a 41-year career and 165 publications: 51 as first or single author (author), 69 as intermediate author (collaborator) and 45 as last author (manager). This imaginary scientist has received about 9,400 citations (17% self-citations): 2734 as author, 4720 as collaborator, and 1948 as manager. The average h-index is 47, and the mean c-score is 3.65. These metrics show weak correlation and little dependence on career length. Rankings differ markedly depending on whether the h-index or c-score is applied. Palaeontologists with high h-indices (h-palaeontologists) typically have more papers and citations, especially as collaborators or managers, and higher self-citation rates. In contrast, those with high c-scores (c-palaeontologists) generally produce fewer papers and citations overall, show lower self-citation rates and obtain a larger share of citations from work as authors rather than collaborators or managers. Expanding the database to include the broader palaeontological community would enable a more comprehensive assessment of citation performance and better inform evaluation practices. To the author’s knowledge, this is the first global, discipline-wide analysis conducted using the SR.
This study analyses the diverse types of bioerosion marks on the shells of two sea turtle specimens from the Lutetian (middle Eocene) of Belgium. The objective is to understand the physical stressors affecting these organisms in ancient marine environments and to identify the potential factors responsible for these changes. The first specimen, the holotype of Eochelone brabantica, presents multiple erosive anomalies on its costal plates. The second individual, corresponding to Puppigerus camperi, exhibits different types of shell deviations, also of an erosive character. The combination of macroscopic and imaging techniques (i.e., CT scanning and 3D surface scanning) allow us the precise observation and identification of the different alterations. Comparative analyses suggest several external factors as potential causes of the anomalies of the two specimens (i.e., invertebrate feeding traces and trauma). This detailed examination provides specific insights into the types and causes of shell alterations in these Eocene turtles, offering a clearer understanding of their interactions in the marine ecosystem in which they lived.
Sergio Moreno, Mohamed Amine Doukani, Ana Hipólito
et al.
During the last two decades, the Macaronesian archipelagos have been the focus of multiple studies targeting the abundant and diversified fossil record from late Neogene and Quaternary deposits. This record of past biota, ecosystems and climates is crucial for understanding the impact of glacial–interglacial cycles on Atlantic littoral marine organisms. Coupled with ongoing studies on the factors responsible for global climate change and associated sea-level variations, they contributed decisively towards the development of the modern marine island biogeography theory. Our current knowledge of the evolutionary and biogeographic history of the past and extant, shallow-water marine organisms from the Macaronesian geographic region relies on detailed analysis of many individual fossiliferous outcrops by means of quantitative and qualitative methodologies. Here, we focus on the fossil record of a newly studied MIS 5e outcrop at Pedra-que-pica (PQP), on Santa Maria Island (Azores Archipelago, Portugal). This multidisciplinary work integrates geology, paleontology and biology, providing the first detailed description of the sedimentary facies and stratigraphic framework of the PQP MIS 5e sequence that, coupled with the documentation of the biodiversity and ecological composition of PQP molluscan assemblages, allows us to produce a paleoecological reconstruction and to compare PQP with other last interglacial outcrops from Santa Maria Island. Our results increase the number of the Azorean MIS 5e marine molluscs to 140 taxa (116 Gastropoda and 24 Bivalvia). <i>Ervilia castanea</i> (Montagu, 1803) is the most abundant bivalve, while <i>Bittium nanum</i> (Mayer, 1864) and <i>Melarhaphe neritoides</i> (Linnaeus, 1758) are the most abundant gastropod species. In addition, this work emphasizes the crucial importance of complementing quantitative collecting with qualitative surveys of the fossiliferous outcrops, because nearly 42% of the bivalve species and 28% of the gastropod taxa would be missed if only quantitative samples were used. Derivation of Hill numbers and rarefaction curves both indicate that the sampling effort should be increased at PQP. Thus, although Santa Maria Island is recognized by the scientific community as one of the best-studied islands regarding the last interglacial fossil record, this study emphasizes the need to continue with similar efforts in less known outcrops on the island.
JOACHIM T. HAUG, PAULA G. PAZINATO, GIDEON T. HAUG
et al.
Lacewing larvae are mostly predatory, highly mobile larval forms of Insecta. The modern fauna yields several morphotypes of lacewing larvae, each closely associated with a distinct evolutionary lineage within the group of lacewings, Neuroptera. Back in the Cretaceous, about 100 million years ago, many of these larval forms had already evolved. Additionally, many larval forms seem to have been present that are now extinct. We report here a new form, which appears to be extinct now. This new larva has a prominent forward projecting labrum like larval forms of Nevrorthidae and Psychopsidae. It furthermore has (again similar to the latter two) curved venom-injecting stylets formed by mandibles and maxillae. We used quantitative outline analysis to compare the new larva to those of Nevrorthidae and Psychopsidae. The results of this analysis demonstrate that the new larva differs in all aspects of head capsule shape from all known larvae of Nevrorthidae. Its head shape is more similar to that of many larvae of Psychopsidae, yet also here the new larva differs recognisably in one principal component. Also qualitative differences clearly differentiate the new larva from already known ones. Hence, the new larva represents a new, so far unknown morphotype of lacewing larva. This finding adds to the growing 'zoo' of unusual lacewing larvae back in the Cretaceous, indicating that form diversity and ecological diversity of lacewings were much higher 100 million years ago.
Hadis Khalilizadeh, Abbas Ghaderi, Ali Reza Ashouri
et al.
<strong>Abstract</strong>
This study led to identify 30 species and 16 genera of eight different plant macrofossils orders including Equisetales, Cycadales, Bennettitales, Coniferales, Peltaspermales, Ginkgoales, Corystospermales, and Filicales at the Deh-Shiykh section, north of Kerman. According to stratigraphic ranges of the index taxa such as<em> Otozamites furoni, Nilssoniopteris mosafolia, Nilssonia tenuicaulis, Anomozamites major, Coniopteris hymenophylloides, Nilssonia bozorga</em> and<em> Elatides thomasii</em> the age of early Middle Jurassic (Bajocian–Bathonian) is assigned to the Deh-Shiykh section. Middle Jurassic ichno fossils of the Hojedk Formation in the Deh-Sheikh section have been studied for the first time. The study also led to the determination of terrestrial ichno fossils including eight ichno species, belonging to four ichnogenera such as<em> Planolithes</em>, <em>Rhizoliths</em>, <em>Taenidium</em> and <em>Thalassinoides</em>. They have been found alongside the stems of Equisetals. Combination of the results of ichno fossil studies with plant fossils help us to identify the palaeoenvironment. These plant fossils are generally indicator of humid conditions. Moreover, the identified ichnofossils in accordance with the sedimentological studies, represent deltaic environments influenced by the river systems and channels. This is the first study of the combination of three studies of paleontology (Plant macrofossils), sedimentology and ichnology in east central Iran. The results have contributed to the accurate understanding of the paleoenvironment of fossiliferous horizons of the Hojedk Formation.
<strong>Keywords</strong>: Plant macrofossils, Tracefossils, Middle Jurassic, Delta, Kerman.
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<strong>Introduction</strong>
The northern region of Kerman is one of the richest areas of Iran for the study of plant fossils and so far more than 80 taxa have been reported (Khalilizadeh 2010). The first studies on coal deposits in the Kerman region have been carried out by Houtum-Schindler (1881), Stur (1886) and Stahl (1897). In recent years, Mirzaei-Ataabadi (2002) has studied the plant macrofossils of the Hojedk Formation in the Pabdana, Bab-Nizu and Hashuni areas. Vaez-Javadi and Mirzaei-Ataabadi (2006) studied the plant macrofossils of the Hojedk Formation. Ameri et al. (2014a, b) have also studied the biostratigraphy of the Hojedk Formation deposits in the Bab-Hutk section. Studies on these plant macrofossils have been more focused on coal areas and mines, non-coal areas in this respect has been received less attention. In addition, there are no reports of ichnofossil studies of the Jurassic layers of the Kerman region, especially in association with plant fossils. Trace fossils are very useful for understanding the paleoclimates and generally interpreting paleosedimentary environments (Buatois and Mangano 2004). In the present study, which focuses on the study of plantmacrofossils of the Hojdak Formation in Deh-Sheikh section north of Kerman, trace fossils have also been studied along with this macrofossils and the general sedimentology of these layers is also considered.
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<strong>Material & Methods</strong>
Important factors in the identification of plant macrofossils include the characteristics of veins and pinnules, rachis, the grooves on the stem as well as the nodes and inter nodes in sphenophyte. In this study, about 100 plant macrofossil specimens were studied and they were photographed using a Nikon 90D digital camera. The images were processed using Adobe Photoshop CS5. All these specimens are kept in the Museum of Ferdowsi University of Mashhad. Trace fossil studies are usually carried out in the field on a centimeter scale and samples are taken to the lab for further and more detailed examination. In this study, about 20 trace fossil samples were collected. The lithofacies described in the field are divided mainly on the sedimentary texture (especially grain size) and structures; according to the Miall (1985) classification. The identified petrofacies are based on Folk (1980) classification scheme with polarizing microscope. Also, identification of sedimentary environment and subenvironments were interpreted based on the facies characterizes.
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<strong>Discussion of Results & Conclusions</strong>
Based on the plant macrofossils, especially <em>Coniopteris hymenophylloides</em>, <em>Elatides thomasii </em>and <em>Nilssonia friziensis</em>, Middle Jurassic age (Bajocian–Batonian) is confirmed for the studied section. The studied plant macrofossils, especially filicales and horsetails, grow in humid environments. The in situ Equisetal stems have paleoecological significance. Horsetails, are hygrophytes, and adapted to humid conditions (Brea et al. 2009). Osmundaceae have been to warm and humid conditions along the rivers or marshes (Gordenko 2008). Due to the abundance of cycadophyta and ferns in the study area, tropical to subtropical paleoclimate have been reported (Salyukova et al. 2013). The ichno fossil diversity of the deltaic regions is very low (Hobday and Tavener-Smith 1975). Salinity changes, water turbulence, mud influx and etc. are the most important stress in the delta area. The study of 8 ichnospecies in the Deh-Sheikh section shows these traces, are simple. They are similar to those of deltaic systems (Buatois and Mangano 2011). These trace fossils resemble specimens of deltaic systems and are related to the heteropod invertebrates of Scoyenia ichnofacie. According to sedimentological studies, the sedimentary environment of the Hojedk Formation in the Deh-Sheikh section is often interpreted as a deltaic environment (coarsening upward cycles) under the influence of the river (fining upward cycles) which indicate of channel filling and energy depletion periods. From this study, the combination of paleontological, sedimentological and lithological studies with the study of ichnofossils will be very useful and effective in better understanding the palaeoenvironment and with proper interpretation, it will helpful to recognition details and create a clear picture of the environment.
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In the received view of the history of the Modern Evolutionary Synthesis, paleontology was given a prominent role in evolutionary biology thanks to the significant influence of paleontologist George Gaylord Simpson on both the institutional and conceptual development of the Synthesis. Simpson's 1944 Tempo and Mode in Evolution is considered a classic of Synthesis-era biology, and Simpson often remarked on the influence of other major Synthesis figures – such as Ernst Mayr and Theodosius Dobzhansky – on his developing thought. Why, then, did paleontologists of the 1970s and 1980s – Stephen Jay Gould, Niles Eldredge, David M. Raup, Steven Stanley, and others – so frequently complain that paleontology remained marginalized within evolutionary biology? This essay considers three linked questions: first, were paleontologists genuinely welcomed into the Synthetic project during its initial stages? Second, was the initial promise of the role for paleontology realized during the decades between 1950 and 1980, when the Synthesis supposedly "hardened" to an "orthodoxy"? And third, did the period of organized dissent and opposition to this orthodoxy by paleontologists during the 1970s and 1980s bring about a long-delayed completion to the Modern Synthesis, or rather does it highlight the wider failure of any such unified Darwinian evolutionary consensus?
Historically, studies aimed at prospecting and analyzing paleontological and neontological data to investigate species distribution have developed separately. Research at the interface between paleontology and biogeography has shown a unidirectional bias, mostly focusing on how paleontological information can aid biogeography to understand species distribution through time. However, the modern suit of techniques of ecological biogeography, particularly species distribution models (SDM), can be instrumental for paleontologists as well, improving the biogeography-paleontology interchange. In this study, we explore how to use paleoclimatic data and SDMs to support paleontological investigation regarding reduction of taxonomic uncertainty. Employing current data from two neotropical species (Lagostomus maximus and Myocastor coipus), we implemented SDMs and performed model validation comparing hindcasts with dated fossil occurrences (~14k and ~20k years back present, respectively). Finally, we employed the hindcasting process for two South American fossil records of a misidentified species of caiman (Caiman sp.) to show that C. latirostris is the most likely species identity of these fossils (among four candidate species: C. latirostris, C. yacare, C. crocodilus, and Melanosuchus niger). Possible limitations of the approach are discussed. With this strategy, we have shown that current developments in biogeography research can favour paleontology, extending the (biased) current interchange between these two scientific disciplines.
The educational benefits of replacing in-class lectures with hands-on activities are clear. Such active learning is a natural fit for paleontology, which can provide opportunities for examining fossils, analyzing data and writing. Additionally, there are a number of topics in the field that are exciting to geology majors and non-majors alike: very few can resist the lure of dinosaurs, huge meteor impacts, vicious Cretaceous sharks or a giant Pleistocene land mammal. However, it can seem difficult to introduce these techniques into a large general education class full of non-majors: paleontological specimens provide a natural starting point for hands-on classroom activities, but in a large class it is not always practical or possible to provide enough fossil material for all students. Here I will briefly introduce different types of active learning approaches, and then explain how I have applied these to a large introductory paleontology class for non-majors.
People hold a variety of prior conceptions that impact their learning. Prior conceptions that include erroneous or incomplete understandings represent a significant barrier to durable learning, as they are often difficult to change. While researchers have documented students' prior conceptions in many areas of geoscience, little is known about prior conceptions involving paleontology. Here, data on student prior conceptions from two introductory undergraduate paleontology courses are presented. In addition to more general misunderstandings about the nature of science, many students held incorrect ideas about methods of historical geology, Earth history, ancient life, and evolution. Of special note are student perceptions of the limits of paleontology as scientific inquiry. By intentionally eliciting students' prior conceptions and implementing the pedagogical strategies described in other Elements in this series, we can shape instruction to challenge this negative view of paleontology and improve student learning.
Fluorescence using ultraviolet (UV) light has seen increased use as a tool in paleontology over the last decade. Laser-stimulated fluorescence (LSF) is a next generation technique that is emerging as a way to fluoresce paleontological specimens that remain dark under typical UV. A laser’s ability to concentrate very high flux rates both at the macroscopic and microscopic levels results in specimens fluorescing in ways a standard UV bulb cannot induce. Presented here are five paleontological case histories that illustrate the technique across a broad range of specimens and scales. Novel uses such as back-lighting opaque specimens to reveal detail and detection of specimens completely obscured by matrix are highlighted in these examples. The recent cost reductions in medium-power short wavelength lasers and use of standard photographic filters has now made this technique widely accessible to researchers. This technology has the potential to automate multiple aspects of paleontology, including preparation and sorting of microfossils. This represents a highly cost-effective way to address paleontology's preparatory bottleneck.