Paleobiology Research Papers - Academia.edu (original) (raw)

2025, bioRxiv (Cold Spring Harbor Laboratory)

In virtue of remarkable tolerance on hypoxia and adaptive specialization in morphology, diverse hexactinellid sponges were prosperous in an early Cambrian living condition that characterized by dysoxic to anoxic bottom waters documented by black shales. New fossils from the black shale of Niutitang Formation (basal Stage 3 of Cambrian) in Hunan Province of China, reveal for the first time an articulated body of the sponge Hyalosinica archaica Mehl & Reitner in Steiner et al., 1993, which possesses an ovoid main body and an impressive long stalk. The specular skeleton includes large diactines that are generally organized as fan-shaped clusters, a few small stauractines and hexactines, and twisted bundles of long monaxons that form the stalk/root tuft. This hexactinellid sponge represents the oldest extinct taxon that took advantage of a long stalk to elevate the main body above the sediment surface and thus to adapt to the oxygen-deficient sea-bottom environment. The long root tuft links Hyalosinica to a series of fossil and recent sponge taxa and proves a deep origin of the stalk-bearing morphology, indicating a likely parallel evolution within the Hexactinellida in response to special environmental pressures. Furthermore, the overall skeletal organization indicates that Hyalosinica, as well as related early "rossellimorphs", are basal stem group representatives of Hexactinellida and probably branched before the extinct Reticulosa and before the two extant hexactinellid subclasses.

2025

Intentional dental modification, in the form of ablation and filing, is reported for the first time from Cambodia in two late prehistoric sites (Phum Snay and Phum Sophy, c. 2500 to 1500 yrs BP). Bioarchaeological research is relatively new for this region and this study significantly adds to our reconstruction of past behaviours in mainland Southeast Asia. The skeletal samples combine both excavated material and large looted collections in the form of ossuaries. People from Phum Sophy and Phum Snay had similar rates of anterior maxillary dental ablation, 60% and 47% respectively, and 21.4% and 7.7%, respectively, in the mandible. Patterns of ablation most commonly involve the removal of the maxillary lateral incisors. Intentional filing was less common than ablation but affected Phum Snay and Phum Sophy individuals to a similar level (4-7%). Filing was also restricted to the anterior dentition and a range of patterns were evident, many involving filing of the mesial and distal aspect of the crown of the upper and lower incisors and canines to give a pointed appearance. Patterns of ablation or filing were not strongly associated with a particular sex or age group. However, a limited number of ablation and filing patterns were exclusive to each site. The significance of this practice in relation to rites of passage, status, community and family relationships, and trauma is discussed. It is also shown that the modifications show distinct differences in prevalence and pattern, particularly that of filing, to nearby temporal neighbours in southern Cambodia and northeast Thailand suggesting a unique cultural behaviour for this region.

2025

The dental health of two Cambodian Iron Age (500 BC to 500AD) communities is interpreted through an analysis of advanced wear, caries, periapical lesions, and antemortem tooth loss (AMTL). The two communities, Phum Snay and Phum Sophy, just 40 kilometres apart, are temporally situated at a time of significant socio-political change prior to the establishment of Angkorian state rule. Dental pathology frequencies are compared between the two communities and with other prehistoric sites throughout Southeast Asia to determine whether dental health was affected by socio-political changes and the intensification of rice agriculture that also occurred at this time. The people of Snay and Sophy, despite their proximity, were found to exhibit significant differences in dental health. When subdivided by age and sex, Sophy older age class teeth had significantly more advanced wear, and older females had more periapical lesions, while the Phum Snay older age dentitions had significantly more AMTL. Caries rates were similar between the samples. When compared in the broader context of the Iron Age in prehistoric Southeast Asia, both Phum Snay and Phum Sophy suggest a trend of declining dental health during the period prior to the rise of the Angkorian state.

2025, Animal Biodiversity and Conservation

Hybridization, understood here as the sexual reproduction between
individuals of different species, is relatively common in riverine, estuarine, and
marine environments. Investigating hybridization in wild populations of aquatic
megafauna species provides important insight into their biology, evolution, and
conservation. Here, we conducted an extensive and systematic review of published
reports of hybrids in keystone, aquatic megafauna, aiming to provide a clear
summary of state-of-the-art and hybridization trends in this group. We selected
129 journal articles reporting 80 hybrids in aquatic megafauna. We included
mammals (40.3 %), turtles (33.3 %), crocodilians (17.8 %), and elasmobranchs
(8.5 %) that are widely distributed in oceans and continental waters. Our results
showed a clear increase in reports of hybrids involving aquatic megafauna in
recent years, possibly reflecting the improvement in molecular techniques. However,
this increase could also be a consequence of translocation of organisms and
habitat modification by humans, and may have a critical impact on conservation,
particularly regarding already depleted populations. Hybridization has directly or
indirectly facilitated the extinction of many species, but it has also played a crucial
role in the evolution and adaptation of many others. To determine whether
hybridization is a natural effect or a collateral effect of anthropic pressures we
need to understand its implications on the conservation of aquatic megafauna.

2025

A new Late Cretaceous turtle, Angolachelys mbaxi gen. et sp. nov., from the Turonian (90 Mya) of Angola, represents the oldest eucryptodire from Africa. Phylogenetic analysis recovers Angolachelys mbaxi as the sister taxon of Sandownia harrisi from the Aptian of Isle of Wight, England. An unnamed turtle from the Albian Glen Rose Formation of Texas (USA) and the Kimmeridgian turtle Solnhofia parsonsi (Germany), are successively more distant sister taxa. Bootstrap analysis suggests those four taxa together form a previously unrecognized monophyletic clade of marine turtles, herein named Angolachelonia clade nov., supported by the following synapomorphies: mandibular articulation of quadrate aligned with or posterior to the occiput, and basisphenoid not visible or visibility greatly reduced in ventral view. Basal eucryptodires and angolachelonians originated in the northern hemisphere, thus Angolachelys represents one of the first marine amniote lineages to have invaded the South Atlantic after separation of Africa and South America.

2025, Acta Geologica …

The presence of the ichnospecies Arachnostega gastrochaenae Bertling, 1992 is documented from the Cambrian for the first time. it occurs in several stratigraphical levels of the middle Cambrian sediments in the Příbram-Jince and... more

2025, Earth-Science Reviews

Tuscany has a rich Pliocene record of marine megafauna (MM), including mysticetes, odontocetes, sirenians and seals among the mammals, and six orders of sharks among the elasmobranchs. This is reviewed with respect to paleogeography and sequence-stratigraphic occurrence in six different basins. Conditions at the ancient seafloor are explored by means of sedimentary facies analysis, taphonomy and multivariate techniques applied to a large quantitative dataset of benthic molluscs. MM is rare or absent in most basins during the Zanclean, except in one basin, and most abundant in Piacenzian deposits in all six basins. MM occurs preferentially in fine-grained shelfal highstand deposits of small-scale depositional sequences, or at condensed horizons of the maximum flooding interval. It is rare in shallow marine paleonvironments and nearly absent in bathyal paleosettings. Paleogeographic and paleoecological evidence and a comparison with modern patterns of marine upwelling suggest that a wedge of nutrient-rich waters sustained in the offshore during the Pliocene a high biomass of primary producers and a community of apex consumers and mesopredators, similarly to the modern Northwestern Mediterranean Sea, with a higher speciesrichness than the modern. The highest MM diversity coincides with the mid-Piacenzian warm period, suggesting that facies control does not obscure a link between climate and diversity. We underline however that not all marine environments were suitable for marine mammal preservation. Buoyant carcasses were preferentially dismembered and destroyed in high-energy shallow waters, with the possible exception of delta front deposits, where sudden sediment input occasionally buried pristine carcasses. We hypothesise that carcasses sunken on the seafloor below the shelf break underwent destruction through the activity of a whale-fall biota of modern type, specialised in the consumption of decomposing tissues, both soft and mineralised. A taphonomic window was left between storm wave base and the shelf break. Here water pressure is high enough to prevent the formation of decomposing gases and the resurfacing of carcasses, while the lack of a specialised whale-fall biota slows down bone degradation with respect to deeper settings. Sedimentation rate was high enough to cover skeletal material before its complete destruction. An estimate of paleobathymetries based on multivariate techniques suggests that the preferential depth for the inclusion of MM in the fossil record was 30-300 m. The results are compared with major Mesozoic and Cenozoic MM records worldwide. Available evidence suggests that the late Neogene radiation of large whales, true ecosystem engineers, and their size increase, triggered the radiation of a bone-eating fauna that hampered, and hampers, MM preservation in the deep sea. Stratigraphic paleobiology and an ecosystem-level approach deliver useful insights in the nature of the fossil record.

2025, Proceedings of The Royal Society B: Biological Sciences

The nature of the pteroid, a rod-like bone projecting from the carpus in pterosaurs, has long been disputed. Three lines of evidence, morphological, developmental and histological, indicate that the pteroid is a true bone, rather than ossified cartilage. The origin of the pteroid is unclear: it may be a modified carpal, the first metacarpal, or a neomorph.

2025, Fossilia - Reports in Palaeontology

2025

The Paragaricocrinidae is an enigmatic late Paleozoic family of camerate crinoids that retained a robustly constructed calyx more typical of Devonian to Early Mississippian crinoids. The discovery of the oldest member of this family, Tuscumbiacrinus madisonensis n. gen. n. sp., initiated a phylogenetic investigation of the Paragaricocrinidae and consideration of its diversification and paleobiogeographic distribution. Phylogenetic analyses demonstrate the need to describe Tuscumbiacrinus n. gen and conduct revisions to preexisting taxa, resulting in the description of Palenciacrinus mudaensis n. gen. n. sp.; Pulcheracrinus n. gen.; Nipponicrinus hashimotoi n. gen. n. sp.; and Nipponicrinus akiyoshiensis n. gen. n. sp. Megaliocrinus exotericus Strimple is reassigned to Pulcheracrinus n. gen. In addition to having an anachronistic morphology, relatively few specimens are known through the ca. 76-million-year duration of this family. This pattern is unlikely to have resulted from low fossil sampling alone, and instead likely reflects low abundance and/or taxonomic richness of a long-lived waning clade. From its apparent origination in Laurussia during the Mississippian, the Paragaricocrinidae diversified into a cosmopolitan clade. Following a diversity drop during the Pennsylvanian, the Paragaricocrinidae persisted but exemplified characteristics of a dead clade walking until its eventual extinction during the middle Permian (Wordian). http://zoobank.org/3e5df71c-112f-4556-96c5-a5a62d4a4da9 Non-technical Summary A new crinoid, Tuscumbiacrinus madisonensis n. gen. n. sp., is described from the Middle Mississippian (about 340 million years ago) of northern Alabama. It belongs to the enigmatic family Paragaricocrinidae, which is now known globally from the Middle Mississippian through the middle Permian. Tuscumbiacrinus n. gen. is the oldest known representative of this family. A re-examination of the entire family resulted in the recognition of four new genera, four new species, and one species is reassigned to a new genus. The Paragaricocrinidae is unusual because the anatomical construction of the body is more typical of morphologies characterizing Middle Paleozoic crinoids than Late Paleozoic forms. Further, very few specimens of this family are known, especially from the Permian. Following an abrupt drop in clade diversity, phylogenetic and macroevolutionary patterns indicate the Paragaricocrinidae exemplify patterns similar to a "dead clade walking," in which a clade temporally persists after a decline at low taxonomic richness, abundance, and ecologic innovation before finally becoming extinct.

2025, Palaeogeography, Palaeoclimatology, Palaeoecology

High survival and at least regional blooms of siliceous marine groups, with coeval retreat of calcareous organisms, is known from the Frasnian-Famennian (radiolarians, silicisponges) and end-Cretaceous (diatoms, radiolarians) mass extinctions. A strictly actualistic approach to the palaeoecology of silica-secreting biota is of limited significance, especially for silica-enriched and oligotrophic Palaeozoic epeiric seas and, in particular, during biotic turnovers. Adaptation among silica-secreting marine plankton has led toward more efficient utilization of shrinking dissolved silica resources within surface waters of Cenozoic oceans, as shown by both radiolarians and diatoms. This biosiliceous signal during the major biotic crises is mostly explained by a large-scale increase in volcano-hydrothermal activity during major plate-boundary re-arrangements, triggering global ecosystem perturbations. The cumulative stimulus favoured siliceous versus calcareous biota growth, deposition and preservation because of (1) a higher rate of input of silica and other nutrients, promoting eutrophication pulses, (2) a punctuated (or reversed) greenhouse climatic effect, episodically coupled with (3) vigorous oceanic circulation due to a variety of volcanogenic upwellings and turnovers. Siliceous communities, adapted to more eutrophic conditions, have thrived in the stressed niches. On the other hand, expanding anoxia and nutrification may lead to a stepwise loss of deep-water niches and consequent selective decline of more specialized oligotrophic radiolarians and other pelagic biota. By contrast, siliceous faunas experienced severe non-selective losses during the end-Permian mass extinction (recorded as a 'chert gap'). Thus, the greatest environmental disaster of the Phanerozoic was driven by a unique set of killing factors, extremely effective for radiolarian productivity, e.g., due to the combination of a drastic volcanic winter with expanding superanoxia.

2025

Este texto refiere al proyecto Fosilífera de Lorena Mal, una investigación en la cual la artista se enfoca en los registros fósiles de más de 100 millones de años encontrados en la zona de Tepexi de Rodriguez, Puebla. Este proyecto de largo aliento, ha sido desarrollado en diálogo y colaboración con las comunidades de Tepexi, Santa Inés Ahuatempan y el Instituto de Geología de la UNAM.

2025, Geodiversitas

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

2025

The sternum is a highly modi ed breastbone. The two primary  ight muscles are the pectoralis major (largest muscle in the bird's body) and the supracoracoideus. The pectoralis major acts to depress the wing in downstroke whereas the supracoracoideus is the primary elevator of the wing in the upstroke and is most important for take-off Both these muscles originate from carina (keel) of the sternum. ln  ying birds, keel or carina is well developed for  ight muscle attachment (called a carinate sternum). Flightless birds have keelless or "ratite sternum". Thus, sternum is one of the important bones involved in night mechanism. Very little information is available on morphometry of some common  ight birds such as pigeon, crow and owl. Keeping this in view. the present study was conducted.

2025

. -***Setmenat (España) En honor a mi padre D. Juan Corbacho, persona honesta y veraz, quien me inició en el fascinante mundo de los fósiles (primer autor).

2025

Recently two new species of the genus Platypeltoides (Nileidae, Trilobita) from the Anti-Atlas region of Morocco have been described. Because new material is still appearing in this area, we have considered to review this subject. The aim of this article is to describe all the species of the genus Platypeltoides appeared in the Lower Fezouata Formation (Tremadocian, Lower Ordovician) and distributed in three different locations of the Moroccan Anti-Atlas. Several specimens of this genus and kept in the Museo Geológico del Seminario (Barcelona, Spain), Museo Geominero (Madrid, Spain) and the Natural History Museum (London, UK) are here described and discussed. In this paper, all known species of the Platypeltoides genus of Morocco are presented. All them appear in the Zagora region and in the Guelmim area. Three species have already been described: P. magrebiensis?, P. hammondi and P. carmenae. We left two more in open nomenclature, Platypeltoides aff. carmenae and Platypeltoides sp. Finally, another species changes its genus: Asaphellus cuervoae = Platypeltoides cuervoae. Indeed, four species (but possibly two more) of the genus Platypeltoides are present in the Lower Ordovician of Morocco.

2025

All the specimens of trilobites Asaphellus cuervoae Corbacho & López-Soriano, 2012 coming from an outcrop in the Lower Ordovician in Goulmin (Morocco) are studied. Almost all specimens appear in pairs in which the larger is placed below. It is proposed tentatively that this is evidence of sexual dimorphism and also perhaps a possible copulation. RESUMEN -Se estudian prácticamente todos los ejemplares de la especie Asaphellus cuervoae Corbacho & López-Soriano, 2012 de un yacimiento del Ordovícico inferior de Goulmin (Marruecos). Casi todos aparecen formando parejas en las que el individuo de mayor tamaño está debajo. Con toda cautela se propone que este hecho sea una prueba de dimorfismo sexual y quizá de copulación,

2025, Journal of Vertebrate Paleontology

The dodo Raphus cucullatus Linnaeus, 1758, an extinct and flightless, giant pigeon endemic to Mauritius, has fascinated people since its discovery, yet has remained surprisingly poorly known. Until the mid-19th century, almost all that was known about the dodo was based on illustrations and written accounts by 17th century mariners, often of questionable accuracy. Furthermore, only a few fragmentary remains of dodos collected prior to the bird's extinction exist. Our understanding of the dodo's anatomy was substantially enhanced by the discovery in 1865 of subfossil bones in a marsh called the Mare aux Songes, situated in southeastern Mauritius. However, no contextual information was recorded during early excavation efforts, and the majority of excavated material comprised larger dodo bones, almost all of which were unassociated. Here we present a modern interdisciplinary analysis of the Mare aux Songes, a 4200-year-old multitaxic vertebrate concentration Lagerst€ atte. Our analysis of the deposits at this site provides the first detailed overview of the ecosystem inhabited by the dodo. The interplay of climatic and geological conditions led to the exceptional preservation of the animal and associated plant remains at the Mare aux Songes and provides a window into the past ecosystem of Mauritius. This interdisciplinary research approach provides an ecological framework for the dodo, complementing insights on its anatomy derived from the only associated dodo skeletons known, both of which were collected by Etienne Thirioux and are the primary subject of this memoir.

2025, junge Welt

in: junge Welt vom 12. Juni 2025

2025, The relationship between bone shell microanatomy and palaeoecology in Testudinata from South America

Extant turtles exhibit a range of ecological adaptations to terrestrial and pelagic marine habitats. Bone shell microanatomy, and specifically, qualitative and quantitative approaches to shell bone porosity, have been used to infer palaeoecology and habitat. However, such inferences are hindered by the lack of a comprehensive sampling of testudine taxa and, in some instances, of long bones of vertebrates other than turtles. In this paper, we carry out an osteohistological analysis of Testudinata shell bones, including 31 different taxa, both extant and extinct, of known habitats. Costal and peripheral elements of published species and new data presented here are statistically analysed. Although, in some cases, values are congruent with those expected for a particular habitat (e.g. Hydromedusa casamayorensis), this is not true for all taxa examined. Moreover, microanatomical features of several taxa (e.g. Chelonia mydas) are inconsistent with habitat data. Results indicate that, although the microanatomical structure of the shell is related to habitat, this is not the only influence and indeed, in several cases, not the most important factor.

2025

Se hace un análisis critico del término olistopaleobiocenosis propuesto por Calzada (1978 a). Se concluye que dicho término es innecesario y contradictorio, induciendo a error, ya que en realidad sirve para designar tanatocenosis, las cuales ya han sido completamente caracterizadas en otros trabajos. A critica] analysis of the term «olistopaleobiocenosis» proposed by Calzada (1978 a) is made. We conclude that the term is unnecessary and contradictory, because, actualey, it represents the concept of thanatocenosis, which has been well-defined in other papers.

2025

RÉSUMÉ: Avant Homo neanderthalensis différents types d'hominidés occupèrent l'Europe dont Homo heidelbergensis. L'objet de cette étude était de rechercher par une analyse morphométrique du frontal les variations entre ces deux espèces d'une part, et entre ces espèces et l'Homme moderne d'autre part. L'étude a porté sur 36 frontaux d'hommes fossiles européens (10 Homo heidelbergensis, 26 Homo neanderthalensis) et un échantillon de 60 individus modernes d'une nécropole historique française. Deux méthodes ont été associées: une étude métrique et des superimpositions Procustes. Un aplatissement et élargissement de l'écaille frontale et un arrondissement des cavités orbitaires chez Homo neanderthalensis par rapport à Homo heidelbergensis ont été mis en évidence. Cette étude ne permet pas de trancher entre cladogenèse ou anagenèse lors de la transition Homo heidelbergensis – Homo neanderthalensis en Europe, mais démontre une nette différence dans le...

2025, PaleoBios

The Paleobiology Database is an online, non-governmental, non-profit public resource for paleontological data. It is organized and operated by a multi-disciplinary, multi-institutional, international group of paleobiological researchers. This volume is designed to be a comprehensive guide for Paleobiology Database users, both General and Contributory. It covers most database uses from data retrieval and mapping to data contribution of all types. It contains numerous examples to illustrate database use as well as definitions of terms and additional links to numerous other sources. We hope that this user guide will help all users access the great volume of data in the Paleobiology Database and lead others to start and continue to add data to the system.

2025

The time separating the first appearances of species from their divergences from related taxa affects assessments of macroevolutionary hypotheses about rates of anatomical or ecological change. Branch durations necessarily posit stratigraphic gaps in sampling within a clade over which we have failed to sample predecessors (ancestors) and over which there are no divergences leading to sampled relatives (sister-taxa). The former reflects only sampling rates whereas the latter reflects sampling, origination and extinction rates. Because all three rates vary over time, the probability of a branch duration of any particular length will differ depending on when in the Phanerozoic that branch duration spans. Here, I present a birth-death-sampling model allowing interval-to-interval variation in diversification and sampling rates. Increasing either origination or sampling rates increases the probability of finding sister taxa that diverge both during and before intervals of high sampling/origination. Conversely, elevated extinction reduces the probability of divergences from sampled sister-taxa before and during intervals of elevated extinction. In the case of total extinction, a Signor-Lipps will reduce expected sistertaxa leading up to the extinction, with the possible effect stretching back many millions of years when sampling is low. Simulations indicate that this approach provides reasonable estimates of branch duration probabilities under a variety of circumstances. Because our current probability models for describing morphological evolution are not as advanced as our methods for inferring diversification and sampling rates, branch duration priors allowing for time-varying diversification and could be a potent tool for phylogenetic inference with fossil data.

2025, Paléorient

Le Chalcolithique (4500-3600 cal. av. J.-C.) du Levant Sud est le foyer d’une différentiation sociale et d’une spécialisation économique accrue. Parmi les principales sources de spécialisation économique figurent les produits d’origine animale, particulièrement les produits dérivés des moutons, chèvres et bovins. Les suidés tiennent également une place importante, bien que négligée dans la littérature. Dans cet article, nous utilisons les informations relatives à la faune provenant du site de Marj Rabba en Basse Galilée. Nous étudions en particulier les courbes d’abattage, les données métriques, ainsi que les artefacts. Afin de distinguer les chèvres des moutons, nous avons analysé l’empreinte collagène (ZooMS) des dents de caprinés. Ces données sont comparées à celles d’autres sites chalcolithiques du Levant Sud afin d’explorer les différences régionales en termes de stratégies de gestion des troupeaux durant cette phase cruciale de changements socio-économiques. À l’inverse des si...

2025, Paleobiology

Geological data show that high Andean habitats have been available for plant colonization only since the end of the Tertiary. The manner in which plant species moved into these habitats, the times during which, and the methods by which they differentiated during the Pleistocene varied altitudinally and latitudinally along the tropical Andes. The process of speciation in all areas, however, was the same as that in temperate environments, namely, geographic isolation and subsequent divergence. Except on the Altiplano, most plant species expanded their ranges during glacial periods when vegetation zones were lowered. In the northern paramos at elevations above treeline, colonization was greatest during glacial periods but has always occurred in a manner similar to that of oceanic islands. At lower elevations in the northern Andes, and along the Eastern Cordillera, direct migration was possible in glacial times because of increased contiguity of upper montane forest habitats. On the upper slopes of the west coast of Peru'i, glacial-age plant migrations were fostered more by cllanges in precipitation than by the lowering of vegetation belts. In all of these areas, interglacial periods were, and are, times of isolation and differentiation. Across the Altiplano in contrast, glacial periods were times of population fragmentation accompanied by differentiation and/or speciation.

2025, Journal of Human Evolution

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2025, MITTEILUNGEN DER GESELLSCHAFT FÜR URGESCHICHTE

Oscar Fraas was one of the first natural scientists to establish the existence of Ice Age humans.
From November 1854 until 1894, he held various positions in the Royal Natural History Cabinet
in Stuttgart. As early as the 1860s, he conducted a series of experiments to explain and under
stand how traces and scratches on Ice Age bone fragments were made. His work is among the
first attempts in the world to use Stone Age tools. These were often spontaneous field experi
ments whose results he did not verify or whose variables are no longer evident today. At the
time, however, Fraas’ work was far ahead of most of his colleagues. Overall, Fraas described
several attempts to fragment bones and dissect animals using bear mandibles.
The following article provides an overview of the experiments carried out by Fraas. In addition,
we will present for the first time the perforated horse teeth and bone retouchers from the first
archaeological excavation in Hohle Fels in 1870/71 directed by Fraas, which are curated in the
collection of the State Museum of Natural History Stuttgart. A new radiocarbon date establishes
that Fraas reached at least as deep as the Gravettian layers during his excavation at Hohle Fels.

2025

Anlässlich des Jubiläums "150 Jahre Ausgrabung im Hohle Fels" wurden die Funde im Staatlichen Museum für Naturkunde Stuttgart in Augenschein genommen. Sie lagern dort wohl geordnet seit der ersten Ausgrabung von Oscar Fraas 1870/71 (Abb. 1 & 2). Dabei stellte sich heraus, dass trotz der hervorragenden Magisterarbeit von Cornelia Saier (1994), noch viele Fragen zur Grabungstätigkeit von Oscar Fraas im Hohle Fels und zu den verschiedenen Fundkategorien offenblieben. Insbesondere die Vielzahl an durchbohrten Pferdezähnen warf die Frage nach dem Alter der Funde auf. Die Ausgrabungen von Oscar Fraas versuchen wir in ihrem zeitgeschichtlichen Kontext zu sehen. Die vorgeschichtliche Archäologie ist eine vergleichsweise junge Forschungsdisziplin. Der erste Lehrstuhl für Prähistorische Archäologie wurde 1892 an Moritz Hoernes in Wien vergeben. Daneben gruben oft Geologen oder wissenschaftlich interessierte Laien. Der folgende Artikel gibt einen Überblick über die von Fraas durchgeführten Experimente. Zudem werden die durchlochten Pferdezähne und die Knochenretuscheure der ersten archäologischen Grabung im Hohle Fels 1870/71 unter der Leitung von Fraas erstmalig vorgestellt, die in der Sammlung des Staatlichen Museums für Naturkunde Stuttgart kuratiert werden. Eine neue Radiokohlenstoffdatierung belegt, dass Fraas während seiner Grabung im Hohle Fels mindestens die Tiefe der gravettienzeitlichen Schichten erreichte.

2025, International Geology Review

Metasedimentary complexes dispersed all along the northwestern branch of the Caribbean orogenic belt between Yucatan and the Virgin Islands provide evidence for a major tectonic event of latest Cretaceous (Late Campanian-Early Paleocene) age that played a key role in the evolution of the Caribbean realm. During the northeastward Cretaceous drift of the Caribbean plate from the Pacific, the leading edge of the plate encountered a sedimentary prism that extended southeastward into the Proto-Caribbean realm from the southeastern edge of the Maya Block. Latest Cretaceous subduction of this Mesozoic sedimentary suite, dubbed here "Caribeana," formed metamorphic complexes (i.e., East Yucatán, Cangre, Pinos, Escambray, Guayabal, Asunción, Samaná, and Puerto Rico Trench terranes). This latest Cretaceous subduction/accretion event triggered the interruption or attenuation of the activity of the Cretaceous volcanic arc and the tectonic emplacement of ophiolites and subduction channel complexes along the leading edge of the Caribbean plate. Flat subduction of the Proto-Caribbean ensued during the Maastrichtian-Eocene in the western segment of the leading edge of the Caribbean plate, whereas normal-angle subduction and volcanic arc magmatism continued during the same time span in the eastern segment. The metamorphic complexes evolved differently since the Maastrichtian. As a consequence of the development of the Yucatan Basin in the western part of the orogenic belt, the Pinos, Escambray, and probably the Guayabal terranes were exhumed in an intra-arc environment, whereas the East Yucatan(?), Cangre, Asunción, Samaná, and Puerto Rico Trench terranes were exhumed in a fore-arc setting.

2025

The current study was designed to show the role of aqueous crude extracts against the Giardia lamblia. The study used 20 rats (Adult male) that distributed into four groups; the control group. Second group rat infected with (1X103 cell/ ml) G. lamblia. The third group infected rat was treated with (100mg/ml) aqueous extract for four weeks. The fourth group infected rat was treated with (250mg/ml) aqueous extract for four weeks. The results show a highly significant elevate (P < 0.05) in levels of MDA with a significant (P < 0.05) reduction in levels of catalase in infected rats compared with the control group. The results of treated rats show non-significant (P < 0.05) changes in all parameters compare with the control group when using aqueous crude extracts. About the histological changes, in the second group, kidney sections show damage glomerulus, slough endothelial of tubules, lymphocytes infiltration, thickening wall of blood vessels, and fibroblast. In treated groups ...

2025, Fossil Record

A late Vise ´an section of clastic and carbonatic rocks is described from the eastern part of the Anti-Atlas (Morocco). The sedimentary succession is a mixed carbonate-siliciclastic system influenced by sea-level fluctuations. The sedimentology of the section is interpreted with respect to transgressive-regressive cycles and systems tracts. Highstand sediments yielded ammonoid assemblages from six horizons; a total of 1,040 specimens separated into 20 species are described in the palaeontological section. The genus Itimaites is new, together with the 16 new species Itimaites parabolicus n.

2025, Acta Palaeontologica Polonica

Evolution of the coiled ammonoid conch from the uncoiled bactritid conch was probably coupled with changes in manoeuvrability and swimming velocity. The gradual transformation of uncoiled to coiled ammonoid conchs has essential functional consequences. The radical change in conch geometry during phylogeny but also in ontogeny of early ammonoids implies a shift of the aperture from an original roughly downward, via a downward oblique and an upward oblique to an upward orientation, presuming a neutrally buoyant condition of the ammonoid animal. Similar trends were reconstructed for the three main ammonoid lineages in the Middle Devonian, the agoniatitid, the anarcestid, and the tornoceratid lineages. This allowed an increase in manoeuvrability and in the maximum horizontal swimming speed.

2025, Biological Reviews

Heteromorphs are ammonoids forming a conch with detached whorls (open coiling) or non-planispiral coiling. Such aberrant forms appeared convergently four times within this extinct group of cephalopods. Since Wiedmann's seminal paper in this journal, the palaeobiology of heteromorphs has advanced substantially. Combining direct evidence from their fossil record, indirect insights from phylogenetic bracketing, and physical as well as virtual models, we reach an improved understanding of heteromorph ammonoid palaeobiology. Their anatomy, buoyancy, locomotion, predators, diet, palaeoecology, and extinction are discussed. Based on phylogenetic bracketing with nautiloids and coleoids, heteromorphs like other ammonoids had 10 arms, a well-developed brain, lens eyes, a buccal mass with a radula and a smaller upper as well as a larger lower jaw, and ammonia in their soft tissue. Heteromorphs likely lacked arm suckers, hooks, tentacles, a hood, and an ink sac. All Cretaceous heteromorphs share an aptychus-type lower jaw with a lamellar calcitic covering. Differences in radular tooth morphology and size in heteromorphs suggest a microphagous diet. Stomach contents of heteromorphs comprise planktic crustaceans, gastropods, and crinoids, suggesting a zooplanktic diet. Forms with a U-shaped body chamber (ancylocone) are regarded as suspension feeders, whereas orthoconic forms additionally might have consumed benthic prey. Heteromorphs could achieve near-neutral buoyancy regardless of conch shape or ontogeny. Orthoconic heteromorphs likely had a vertical orientation, whereas ancylocone heteromorphs had a near-horizontal aperture pointing upwards. Heteromorphs with a U-shaped body chamber are more stable hydrodynamically than modern Nautilus and were unable substantially to modify their orientation by active locomotion, i.e. they had no or limited access to benthic prey at adulthood. Pathologies reported for heteromorphs were likely inflicted by crustaceans, fish, marine reptiles, and other cephalopods. Pathologies on Ptychoceras corroborates an external shell and rejects the endocochleate hypothesis. Devonian, Triassic, and Jurassic heteromorphs had a preference for deep-subtidal to offshore facies but are rare in shallow-subtidal, slope, and bathyal facies. Early Cretaceous heteromorphs preferred deep-subtidal to bathyal facies. Late Cretaceous heteromorphs are common in shallow-subtidal to offshore facies. Oxygen isotope data suggest rapid growth and a demersal habitat for adult Discoscaphites and Baculites. A benthic embryonic stage, planktic hatchlings, and a habitat change after one whorl is proposed for Hoploscaphites. Carbon isotope data indicate that some Baculites lived throughout their lives at cold seeps. Adaptation to a planktic life habit potentially drove selection towards smaller hatchlings, implying high fecundity and an ecological role of the hatchlings as micro-and mesoplankton. The Chicxulub impact at the Cretaceous/Paleogene (K/Pg) boundary 66 million years ago is the likely trigger for the extinction of ammonoids. Ammonoids likely persisted after this event for 40-500 thousand years and are exclusively represented by heteromorphs. The ammonoid extinction is linked to their small hatchling sizes, planktotrophic diets, and higher metabolic rates than in nautilids, which survived the K/Pg mass extinction event.

2025, Paleobiology

Mollusks in general and ammonoids in particular are known to display a sometimes profound morphological intraspecific variability of their shell. Although this phenomenon is of greatest importance, it has rarely been investigated and quantified. It is especially crucial for taxonomy and incidentally for biodiversity analyses to account for it, because otherwise, the number of described species might exceed that of actual species within any group. Early ammonoids (Early Devonian, Paleozoic) typically suffer from this bias. For instance, most specimens from the same layer and the same region (e.g., theErbenocerasbeds of the Moroccan eastern Anti-Atlas studied here) differ morphologically from each other. Depending on the importance given to certain morphological characters, therefore, one could create a new species for almost every specimen. In this study, we measured nearly 100 such specimens from a restricted stratigraphic interval and quantified their intraspecific variability. The...

2025, Topics in geobiology

Allometric growth between different parts of the shell often hampers the identification of mollusk shells, particularly in such cases where preadult shell growth varies strongly. Especially in gastropods, the terminal aperture is often less variable and yields morphological information essential for species determination (e.g. Vermeij 1993; Urdy et al. 2010a, b). In fossil mollusk shells, the adult aperture (peristome)is often missing, partially due to an early death, and partially due to destructive processes, which occurred post mortem (taphonomy). Therefore, the entire shell ontogeny is known only from a small fraction of all ammonoid taxa (e.g., . Nevertheless, knowledge of the adult shell of ammonoids is very important since it can yield morphological information essential for systematics and for the reconstruction of various aspects of their paleobiology.

2025, Swiss Journal of Palaeontology

Sigurd von Boletzky was a cephalopod researcher who was world-renowned for his enthusiasm for his field of research, for his friendly and calm personality, and, of course, his publications. He dedicated most of his life as active researcher on the development, biology and evolution of coleoids. Nevertheless, he was always curious to learn about other cephalopods as well. Sigurd passed away in Switzerland on September 28th 2020. We dedicate this text and volume to his memory.

2025, Acta Palaeontologica Polonica

The deer association composed of 'Cervus' cf. cusanus, 'Cervus' pardinensis, Croizetoceros ramosus , cf. Arvenoceros ardei indicates the late Pliocene age (zone MN 16) of the locality Węże 2. Outside Poland the species... more

2025

This study, made on adult ostrich specimens, has the purpose of identifying the main characteristics of the pelvic belt at this bird and was motivated by the desire to complete existing data and to present anatomic elements using the terminology recommended by the Nomina Anatomica Avium. A very strong connection has been noticed between the ilium and the sacrum, strengthened by the forging in the medial plane of the preacetabular parts of the ilium. This aspect is very different from the ischium, which turns from a wide bone at the rest of the species, into a strong long bone at the ostrich that, with the exception of the cranial extremity, is separated through a wide space from the ilium. The absence of well-known anatomical features of birds from other orders was noticed, such as : the ilio-caudal fossa, the iliac oblique crest, the infracristal cavity, etc while observing the existence of some specific features like an unique type of pubic symphysis.

2025, Encyclopedia of Quaternary Science (Third Edition)

Phytoliths are a class of microfossils produced in many, but not all, families of higher plants and composed of amorphous silica or opal. They are a class of microfossils that can be used as a proxy for reconstructing terrestrial vegetation, agricultural practices, and diets, especially in arid, semiarid, and oxidative contexts where pollen is scarce. Although phytoliths are especially abundant and have been well studied in grasses (Poaceae) and sedges (Cyperaceae), they are produced by over 50 families of higher plants. Given their relatively low level of taxonomic resolution they work particularly well in multiproxy projects complementing information from other sources.

2025, Paleobiology

Prospective and early-career paleontologists deserve an accurate assessment of employment opportunities in their chosen field of study. Drawing on a wide range of sources, we have produced an admittedly incomplete analysis of the current status and recent trends of permanent academic employment in the discipline. Obtaining more complete longitudinal data on employment trends is a major difficulty; this is a challenge that needs to be addressed. The number of job seekers is far in excess of available positions. There has been a clear erosion in the number of academic paleontologists in the United States, a trend exacerbated in recent years. The decline, in constant dollars, of federal funding for paleontological research has potential strong negative impacts on future hiring. The loss of paleontology positions has also had a deleterious effect on our professional societies, which have seen a loss of regular (professional) membership, although student membership remains strong. These trends also potentially negatively impact efforts to diversify the field. Professional societies need to better coordinate their efforts to address these serious issues. Individual paleontologists also must become more effective advocates for the importance and relevance of our science.