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DOAJ Open Access 2024
SAUROPOD DIVERSITY (DINOSAURIA: SAUROPODA) OF CERRO OVERO – LA INVERNADA (BAJO DE LA CARPA FORMATION, SANTONIAN), NORTHEASTERN NEUQUÉN BASIN, AND PALEOECOLOGICAL IMPLICATIONS FOR UPPER CRETACEOUS SAUROPOD FAUNAS

Leonardo Sebastián Filippi, Flavio Bellardini, José Luis Carballido et al.

The Upper Cretaceous fossil vertebrate fauna of the Bajo de la Carpa Formation (Santonian), derived from several different locations in the Neuquén Basin, is relatively abundant and diverse, comprising mainly small to medium-sized reptiles, birds and fishes. The Cerro Overo – La Invernada locality (CO – LI), in the north of the basin, records a similar faunal component for that age, but stands out for its relatively greater abundance and diversity of titanosaur sauropods. The study of the materials presented here allows us to establish the presence of specimens of sauropods other than Overosaurus, the only titanosaur recorded so far in the area, the coexistence of small–medium sized forms with larger forms, which in turn represent some forms with more basal characteristics and others with more derived features. The abundance of the record of sauropods in CO – LI shows both morphological and evolutionary variations, so the discovery of more complete specimens will allow paleofaunistic, paleobiological, and paleoecological studies to be carried out. This will provide a better understanding of the role of titanosaurian sauropods in Late Cretaceous ecosystems.

Fossil man. Human paleontology, Paleontology
DOAJ Open Access 2024
Orthoceratoid and coleoid cephalopods from the Middle Triassic of Switzerland with an updated taxonomic framework for Triassic Orthoceratoidea

Alexander Pohle, Christian Klug

Abstract Orthoconic cephalopods are subordinate, but persistent, widespread and regionally abundant components of Triassic marine ecosystems. Here, we describe unpublished specimens from the Anisian (Middle Triassic) Besano Formation at Monte San Giorgio, Switzerland. They can be assigned to two major but unrelated lineages, the Coleoidea and the Orthoceratoidea. The orthoceratoids belong to Trematoceras elegans (Münster, 1841) and occur regularly within the Besano Formation, are uniform in size, and have few available morphological characters. In contrast, coleoids are more diverse and appear to be restricted to shorter intervals. A new coleoid is described as Ticinoteuthis chuchichaeschtli gen. et sp. nov. To better put the orthoceratoids of the Besano Formation into perspective, we also synthesise the current taxonomy of Triassic orthoceratoids on a global scale. The currently used scheme is largely outdated, with very little taxonomic progress in the past 100 years. Despite previous research showing the distinctness of Triassic orthoceratoids from Palaeozoic taxa, they are still commonly labelled as “Orthoceras” or “Michelinoceras”, which are confined to the Palaeozoic. We show that Triassic orthoceratoids probably belong to a single lineage, the Trematoceratidae, which can be assigned to the Pseudorthocerida based on the embryonic shell and endosiphuncular deposits. Many Triassic species can probably be assigned to Trematoceras, but there are at least two additional Triassic orthoceratoid genera, Paratrematoceras and Pseudotemperoceras. Finally, we review the palaeobiogeographic and stratigraphic distribution of the group and outline possible future research directions.

Fossil man. Human paleontology, Paleontology
CrossRef Open Access 2024
Re-description of the holotype of Parapresbytis eohanuman, a pliocene fossil colobine monkey from Mongolia

Tsubamoto Takehisa, Tsogtbaatar Khishigjav, Baasankhuu Soyollkham

We re-found the holotype (PIN 3381-235) of a Pliocene fossil monkey Parapresbytis eohanuman (Mammalia, Primates, Cercopithecidae, Colobinae), which had been collected from the Shaamar fossil locality (Selenge Aimag, northern Mongolia), at Institute of Paleontology, Mongolian Academy of Sciences, Ulaanbaatar, Mongolia. This specimen is now stored in this institute. Here, we provide precise photos of this holotype with some remarks. It is a fused mandibular corpus with a complete left and right dentition, lacking left and right ascending rami. Its ventral part is crushed and broken.

DOAJ Open Access 2023
Xenarthrans of the collection of Santiago Roth from the Pampean Region of Argentina (Pleistocene), in Zurich, Switzerland

Kévin Le Verger

Abstract The present work concerns xenarthrans from the collection of Santiago (Kaspar Jakob) Roth (1850–1924) housed at the Palaeontological Institute and Museum of the University of Zurich, one of the most important collections of Pleistocene mammals from Argentina in Europe. Roth was a paleontologist originally from Switzerland who prospected and collected a large amount of Pleistocene megafauna of the Pampean Region of Argentina. The xenarthrans are the main representatives of this collection in Zurich, with 150 specimens. Since 1920, this material has not been revised and is under studied. The present investigation corresponds to a taxonomic revision resulting in 114 reassignments, leading to document xenarthran diversity and discuss their paleoecologies. The high diversity reflects the paleoecology of the Pampean Region during the Pleistocene, with the various abiotic events that impacted the paleoenvironment of this region. Within the Cingulata, the Pampean Region fauna was probably dominated by glyptodonts with a high representation of Glyptodontinae and Neosclerocalyptinae while within the sloths the highest diversity and abundance is found in the Mylodontinae and Scelidotheriinae. These four clades represent both species with high ecological tolerance (e.g., Glyptodon munizi; Catonyx tarijensis) and ecologically highly specialized species (e.g., Neosclerocalyptus paskoensis; Scelidotherium leptocephalum). The presence of such ecological diversity underlines the status of the Pampean Region as a major interest for paleoecological and paleoenvironmental reconstruction.

Fossil man. Human paleontology, Paleontology
DOAJ Open Access 2023
Further desmostylian remains from the upper Oligocene of Vancouver Island, British Columbia, Canada

BRIAN LEE BEATTY

The North Pacific rim was home to an extinct group of semiaquatic marine mammals, the order Desmostylia, which superficially resembled hippos. Desmostylians are an uncommon fossil vertebrate in most localities where they occur, and Oligocene taxa particularly so. Beyond the type dentition and two femora of Cornwallius sookensis, and the skull and postcrania of Behemotops proteus, both previously described from the region of Muir Creek locality of the upper Oligocene Sooke Formation of southern coast of Vancouver Island, British Columbia, Canada, no other records from this site have been reported. Additional specimens of teeth have now been found in the Royal British Columbia Museum and Canadian Museum of Nature, including a long-forgotten and unreported paratype. In total, three additional teeth, one of B. proteus and two possibly belonging to C. sookensis, are reported here from its type locality. More importantly, the upper molar reported here, as well as UCMP 36078 from Baja California and USNM 181740 from Oregon, all resemble each other but should be considered as belonging to Cornwallius only with caution.

Fossil man. Human paleontology, Paleontology
DOAJ Open Access 2023
A comparison of teeth in Tithonian, Late Jurassic, predatory actinopterygian fishes from Owadów-Brzezinki Lägerstatte and its palaeoecological implications

Łukasz Weryński, Błażej Błażejowski, Mariusz Kędzierski

The Owadów-Brzezinki palaeontological site is known for its very well-preserved fossils of Late Jurassic vertebrates, such as numerous fossil fish teeth and occasional dental bones. Some of these represent well-studied taxa, including the most common large predatory fish, with notable examples of caturoids (such as Strobilodus sp.) and pachycormids (Orthocormus teyleri). The current study presents the microstructure and histological features of the teeth of the selected specimens of the above taxa. They are determined through examinations of tooth cross-sections under thin microscopic observations and by the usage of scanning electron microscopy (SEM). The above inspections, combined with aspects of external tooth morphology, allowed us to determine the palaeoecology of the aforementioned taxa of large predatory fish. It is concluded that examined Caturoidea displayed a rather homogenous dentition belonging to the intermediate cut/slash guild, characterized by an internal orthodentin histology with prominent incremental Andresen growth lines of differing form, indicating living in a highly variable, unstable environment. The teeth of pachycormid specimen (O. teyleri) can be characterized as having denteon-based orthodentin histology, with a rapid rate of tooth eruption and a heterodont, elongated specialist dentition of the piercing guild. The observed structural differences in the teeth suggest a different niche distribution between the taxa studied. They help to explain how these predatory ray-finned fishes may have coexisted both in the local environment of the Owadów-Brzezinki and in the wider, more global context of Late Jurassic shallow marine environments. In addition, the tooth samples are characterised by pronounced surface bioerosion with traces of Mycellites ossifragus durophagous fungal activity, indicating an intense bioerosion caused by these microorganisms after the death of the fish.

Fossil man. Human paleontology, Paleontology
DOAJ Open Access 2022
Paedomorphosis and neurocranial ossification in two Devonian lungfishes

MARIE BOIROT, TOM CHALLANDS, RICHARD CLOUTIER

Lungfishes are one of the few early vertebrate clades with a rich 410-million-years-old fossil record. Lungfishes are characterized by a low evolutionary rate assumed to be associated with paedomorphosis since the Late Devonian. Lungfish paedomorphic trends include a reduction of the number of median fins, reduction of the number of cranial dermal bones, and reduction of the degree of neurocranial ossification. This neurocranial trait has evolved from heavily ossified in Devonian species to completely cartilaginous in post-Devonian species. Neurocranial conditions among derived Devonian lungfishes are needed to have a better understanding of paedomorphosis as a driving force during lungfish evolution. The neurocrania of two Devonian species, Scaumenacia curta (middle Frasnian, Escuminac Formation, eastern Canada) and Pentlandia macroptera (Givetian, Orcadian Basin, Scotland), have been micro-CT-scanned. These species were assumed to have a cartilaginous neurocranium like other “phaneropleurids” and “fleurantids”. Juvenile (or sub-adult) and adult specimens of S. curta possess cartilaginous neurocrania, whereas P. macroptera is now recognized to have a poorly ossified neurocranium. Pyrite filled neurocranial cavities preserving some endocranial structures (e.g., olfactory bulbs, semicircular canals) allow us to code for phylogenetic endocranial characters in S. curta. This unique mode of preservation suggests that occasionally pyrite is a preservative rather than a destructive diagenetic agent. In the evolutionary gap between Pentlandia and Scaumenacia, paedomorphosis had already resulted in reduction of neurocranial ossification while little changes occurred in cranial dermal bones.

Fossil man. Human paleontology, Paleontology
DOAJ Open Access 2021
New skulls of the basal sauropodomorph Plateosaurus trossingensis from Frick, Switzerland: Is there more than one species?

Jens N. Lallensack, Elżbieta M. Teschner, Ben Pabst et al.

The Triassic basal sauropodomorph Plateosaurus trossingensis is well-known from mass accumulations at the German localities of Trossingen and Halberstadt and the Swiss locality of Frick, and is significant especially regarding its taphonomy and proposed developmental plasticity. These implications, however, rely on the assumption that this material derives from a single species, which has been questioned. Here we describe new skull material from Frick including eight complete and six partial skulls, more than doubling the number of known skulls of P. trossingensis. This exceptional sample size allows for gaining a deeper understanding of variability that may occur in a single species. The new material includes the first known juvenile skulls of Plateosaurus, allowing for detecting ontogenetic changes. An attempt is made to distinguish between variability caused by taphonomic plastic deformation and intraspecific variability. Plastic deformation may shorten, but not widen bones. A number of characters commonly included in phylogenetic analyses of basal sauropodomorphs are shown to be variable within P. trossingensis, and possibly require re-evaluation. Although P. trossingensis skulls are highly variable, many of the variable characters include intermediate character states and therefore are continuous. No groupings based on skull features, locality, or stratigraphy are apparent. Consequently, the analyzed skull material from the bonebeds of Frick, Trossingen, and Halberstadt bears no evidence for the presence of more than one species.

Fossil man. Human paleontology, Paleontology
DOAJ Open Access 2021
Publisher Correction to: Swiss Journal of Palaeontology, vol 139

Swiss Journal of Palaeontology

Two [1, 2] articles in volume 139 of the Swiss Journal of Palaeontology published with an incorrect article number, this error was caused by a technical problem during publication. This correction article is to publish the incorrect and correct article numbers.

Fossil man. Human paleontology, Paleontology
DOAJ Open Access 2021
A new Late Triassic dipteridacean fern from the Paso Flores Formation, Neuquén Basin, Argentina

SILVIA CRISTINA GNAEDINGER, ANA MARÍA ZAVATTIERI

Sterile and fertile fronds of dipteridacean ferns from the Paso Flores Formation (late Norian–Rhaetian) at Cañadón de Pancho area, south of the Neuquén Province, Patagonia (Neuquén Basin), Argentina, are described. The Paso Flores Formation specimens comprise an interesting mixture of features showing a unique combination that does not fit in the diagnosis of any of the known fossil genera of Dipteridaceae. Characters such as the number and shape of primary segments in each rachial arm, the coalescence of the primary segments at the base of the frond, the distribution of sori and the number of sporangia per sori allow to differentiate the Paso Flores Formation specimens from the other genera of the family. The new genus and species, Patagoniapteris artabeae is proposed. The specimens share some frond morphological features with the fossil genera Clathropteris, Digitopteris, Thaumatopteris, Sewardalea and with some species of the Dictyophyllum, as well as the characteristic of the sori with the living species Dipteris lobbiana. The Paso Flores Formation environments developed on the western margin of Gondwana under seasonal temperate-warm and humid to sub-humid climates with a marine influence from the west. The Cañadón de Pancho assemblages are late Norian–Rhaetian in age, being the youngest fossil flora recorded from Argentinian Triassic basins to date.

Fossil man. Human paleontology, Paleontology
DOAJ Open Access 2021
Preservation of nautilid soft parts inside and outside the conch interpreted as central nervous system, eyes, and renal concrements from the Lebanese Cenomanian

Christian Klug, Alexander Pohle, Rosemarie Roth et al.

Abstract Nautilid, coleoid and ammonite cephalopods preserving jaws and soft tissue remains are moderately common in the extremely fossiliferous Konservat-Lagerstätte of the Hadjoula, Haqel and Sahel Aalma region, Lebanon. We assume that hundreds of cephalopod fossils from this region with soft-tissues lie in collections worldwide. Here, we describe two specimens of Syrionautilus libanoticus (Cymatoceratidae, Nautilida, Cephalopoda) from the Cenomanian of Hadjoula. Both specimens preserve soft parts, but only one shows an imprint of the conch. The specimen without conch displays a lot of anatomical detail. We homologise the fossilised structures as remains of the digestive tract, the central nervous system, the eyes, and the mantle. Small phosphatic structures in the middle of the body chamber of the specimen with conch are tentatively interpreted as renal concrements (uroliths). The absence of any trace of arms and the hood of the specimen lacking its conch is tentatively interpreted as an indication that this is another leftover fall (pabulite), where a predator lost parts of its prey. Other interpretations such as incomplete scavenging are also conceivable.

Fossil man. Human paleontology, Paleontology
DOAJ Open Access 2021
Multiple Orbitoides d’Orbigny lineages in the Maastrichtian? Data from the Central Sakarya Basin (Turkey) and Arabian Platform successions (Southeastern Turkey and Oman)

Ercan Özcan, Ali Osman Yücel, Rita Catanzariti et al.

Abstract The standard reconstruction of species of Orbitoides d’Orbigny into a single lineage during the late Santonian to the end of the Maastrichtian is based upon morphometric data from Western Europe. An irreversible increase in the size of the embryonic apparatus, and the formation of a greater number of epi-embryonic chamberlets (EPC) with time, is regarded as the main evolutionary trends used in species discrimination. However, data from Maastrichtian Orbitoides assemblages from Central Turkey and the Arabian Platform margin (Southeastern Turkey and Oman) are not consistent with this record. The Maastrichtian Besni Formation of the Arabian Platform margin in Southeastern Turkey yields invariably biconvex specimens, with small, tri- to quadrilocular embryons and a small number of EPC, comparable to late Campanian Orbitoides medius (d’Archiac). The upper Maastrichtian Taraklı Formation from the Sakarya Basin of Central Turkey contains two distinct, yet closely associated forms of Orbitoides, easily differentiated by both external and internal features. Flat to biconcave specimens possess a small, tri- to quadrilocular embryonic apparatus of Orbitoides medius-type and a small number of EPC, whereas biconvex specimens possess a large, predominantly bilocular embryonic apparatus, and were assigned to Orbitoides ex. interc. gruenbachensis Papp–apiculatus Schlumberger based on morphometry. The flat to biconcave specimens belong to a long overlooked species Orbitoides pamiri Meriç, originally described from the late Maastrichtian of the Tauride Mountains in SW Turkey. This species is herein interpreted to be an offshoot from the main Orbitoides lineage during the Maastrichtian, as are forms that we term Orbitoides ‘medius’, since they recall this species, yet are younger than normal occurrence with the accepted morphometrically defined lineage. The consistent correlation between the external and internal test features in O. pamiri implies that the shape of the test is not an ecophenotypic variation, but appears to be biologically controlled. We, therefore, postulate that more than one lineage of Orbitoides exists during the Maastrichtian, with a lineage that includes O. ‘medius’ and O. pamiri displaying retrograde evolutionary features.

Fossil man. Human paleontology, Paleontology
S2 Open Access 2021
Why don’t we look to the west?

H. Widianto, Sofwan Noerwidi

Paleontological data indicate that the beginning of Java Island’s human habitation took place at the Plio-Pleistocene boundary, around 2.4 Ma, along with uplift process and glacial-interglacial cycles. However, the oldest Homo erectus fossil was mainly found in the eastern part of Java Island where age-dating indicates that they were from ca. 1.5 Ma, especially along the riverbanks of Bengawan Solo and Brantas, such as Perning, Sangiran, Kedungbrubus, Ngandong, Ngawi, Trinil, and Sambungmacan.Recently, Pleistocene sites were discovered from the western part of Java, e.g., Rancah (Ciamis), Semedo (Tegal), and Bumiayu (Brebes) with their archeological, paleontological, and paleoanthropological potentials. This work will present the significance of the potential, especially paleoanthropological data from the new sites, and their implications to the Quaternary prehistory research strategies determination in the future.We present new geological, archeological, paleontological, and paleoanthropological evidence from those mentioned sites. The result shows that the distribution of Homo erectus were extended to the western part of Java, between 1.8-1.7 Ma, older than the oldest previous finding of Homo erectus from Perning and Sangiran. This finding suggests a new window of the human arrival on this island. So, why don’t we look to the west? Intensive research in the future should be addressed to the western part of Java Island.

DOAJ Open Access 2020
Oligocene plant assemblage from Rębiszów, Lower Silesia: First “volcanic flora” from Poland

Rafał Kowalski, Grzegorz Worobiec, Elżbieta Worobiec et al.

Fossil plant macroremains preserved in laminated diatomites from Łysa Góra near Rębiszów, Lower Silesia, have been documented for the first time. The fossil assemblage consists mostly of leaves, but fruits, seeds and sporadic flowers also occur. Forty-three identified taxa represent nineteen plant families: Aceraceae, Berberidaceae, Betulaceae, Cornaceae, Cupressaceae, Elaeocarpaceae, Ericaceae, Fagaceae, Lauraceae, ?Leguminosae, ?Meliaceae, Magnoliaceae, Pinaceae, Rhamnaceae, Rosaceae, Salicaceae, Tilioideae, Ulmaceae, Vitaceae, and one incertae sedis. The prevalence of entire margined leaves, mostly represented by Majanthemophyllum basinerve and Daphnogene cinnamomifolia, and a significant presence of Calocedrus suleticensis and Liriodendron haueri, are characteristic features of the Rębiszów flora. The composition of the plant assemblage points to a mesophytic forest with some riparian elements and suggests favourable, warm climatic conditions. Radiometrically dated basalts overlying fossiliferous layers and composition of palynoflora suggest at least Chattian (late Oligocene) age. The lithology and floristic composition link the Rębiszów flora with the so-called volcanic floras of the Nerchau-Flörsheim or Kleinsaubernitz floristic complex (Oligocene) from Germany and Czech Republic with Suletice-Berand flora being especially close.

Fossil man. Human paleontology, Paleontology
DOAJ Open Access 2020
New biostratigraphical data (calcareous nannofossils, ammonites) and Early to Late Barremian transition in the Urgonien Jaune facies and Marnes de la Russille complex of the Swiss Jura Mountains

Eric De Kaenel, Pierre-Olivier Mojon, Antoine Pictet

Abstract In the central Jura Mountains (Western Switzerland), the Urgonien Jaune (UJ) facies with the Marnes de la Russille beds (MRu) have provided very rich nannofloras associated with very rare Tethyan ammonites. A late Early Barremian nannoflora of the Mid-Barremian Event (MBE, following a regional tectonic event of an earliest Barremian synsedimentary tectonic crisis) was found in MRu of the lower UJ and includes 42 genera with 90 species. Among them, Biscutum jurensis De Kaenel, n. sp., Flabellites eclepensensis De Kaenel, n. sp., Palaeopontosphaera giraudii De Kaenel, n. sp., Rhagodiscus buisensis De Kaenel, n. sp., and Vagalapilla rutledgei De Kaenel, n. sp., are recognized as five new species. This nannoflora is a mixture of Boreal and Tethyan taxa with 20 nannofossil markers (Assipetra terebrodentarius, Broinsonia galloisii, Calcicalathina oblongata, Cyclagelosphaera rotaclypeata, Diloma placinum, Ethmorhabdus hauterivianus, Flabellites eclepensensis, Gorkaea pseudoanthophorus, Nannoconus abundans, Nannoconus pseudoseptentrionalis, Palaeopontosphaera giraudii, Palaeopontosphaera pinnata, Placozygus howei, Placozygus reticulatus, Reinhardtites scutula, Rhagodiscus buisensis, Rhagodiscus eboracensis, Tegulalithus septentrionalis, Tubodiscus jurapelagicus, Zeugrhabdotus moulladei) indicating very precisely the nannofossil Zones LK19 (Boreal)–NC5D (Tethyan) as well as the Elegans (Boreal) and Moutonianum (Tethyan) ammonite Zones of the latest Early Barremian. The ammonites in the basal UJ facies of Early Barremian age are reworked Lyticoceras claveli (Nodosoplicatum Zone, Early Hauterivian) and reworked Cruasiceras cf. cruasense (Sayni Zone, early Late Hauterivian), and Pseudometahoplites sp. juv. (Compressissima to Vandenheckii Zones, Early to Late Barremian transition) from the basal MRu. The new palaeontological and sequential results of this study allow a revision of previous data from Godet et al. (2010) precisely assigning a Barremian age to the MRu of the central Jura Mountains (Tethyan Compressissima to lower Sartousiana and Boreal uppermost Fissicostatum to middle Denckmanii ammonite Zones, Boreal LK20B-LK19-LK18 and Tethyan NC5D nannofossil Zones), within the Early to Late Barremian UJ (Tethyan Hugii to lower Sartousiana and Boreal Rarocinctum to middle Denckmanii ammonite Zones, Boreal LK20C to LK18 and Tethyan NC5C-NC5D nannofossil Zones) and below the Late Barremian Urgonien Blanc facies (Tethyan Sartousiana ammonite Zone). ZooBank LSID: urn:lsid:zoobank.org:pub:DDE0EF8B-AC43-4DFC-A029-64224C5D37A7.

Fossil man. Human paleontology, Paleontology
DOAJ Open Access 2020
Jaws of a large belemnite and an ammonite from the Aalenian (Middle Jurassic) of Switzerland

Christian Klug, Walter Etter, René Hoffmann et al.

Abstract Although belemnite rostra can be quite abundant in Jurassic and Cretaceous strata, the record of belemnite jaws was limited to a few specimens from Germany and Russia. Here, we describe and figure three cephalopod jaws from the Middle Jurassic Opalinus Clay of northern Switzerland. Although flattened, the carbonaceous fossils display enough morphological information to rule out an ammonoid, nautiloid or octobrachian origin of the two larger jaws. Their similarities to belemnite jaws from Germany and Russia conforms with our interpretation of these specimens as belemnite jaws. Based on their rather large size, we tentatively assign these two jaws to the megateuthidid Acrocoelites conoideus. The third jaw is a rather small upper jaw of an ammonoid. Since Leioceras opalinum is by far the most common ammonite in this unit in northern Switzerland, we tentatively suggest that the upper jaw belongs to this species.

Fossil man. Human paleontology, Paleontology
DOAJ Open Access 2019
The evolution of early Spermophilus in eastern Europe and the antiquity of the Old World ground squirrels

Maxim V. Sinitsa, Nataliya V. Pogodina

Spermophilus is the most diverse and abundant genus of Eurasian sciurids. Even though many species have been described, the early evolution of the group is poorly understood. Here we present a review of the evolution and taxonomy of early Spermophilus, based on analysis of more than 1500 specimens from the late Pliocene and Early–Middle Pleistocene of Ukraine and European Russia, representing the most complete and continuous fossil record of the early Old World ground squirrels known to date. In addition to documenting previously unpublished specimens of Spermophilus nogaici, we describe a new species, Spermophilus praecox sp. nov., the oldest member of the genus, from the late Pliocene and Early Pleistocene (middle Villanyian to earliest Biharian) of southern Ukraine. It is intermediate in size between a somewhat smaller Spermophilus nogaici and larger Spermophilus polonicus and Spermophilus primigenius. Morphologically, the new species can be distinguished from all known Spermophilus by the retention of primitive traits including a small P3; rudimentary lingual metaloph; large metaconule and mesostyle; presence of P4–M2 endoloph; and premolariform p4 lacking a lingual metalophid. The patterns of dental evolution in eastern European early Spermophilus throughout 2.15 My indicates the existence of a single gradually evolving S. praecox–S. nogaici lineage characterized by a decrease of molar size but enlargement of premolars; the tendency toward high-crowned teeth with more expanded anterior and reduced posterior lobes; well-developed transverse ridges and anterostyles; reduced endolophs, anteroconules, metaconules, and mesostyles of P4–M2; molariform p4; complete m1–m2 metalophids; and stronger m3 hypoconid, hypoconulid, and entoconulid. Dental character regression suggests that Spermophilus evolved from a relatively largesized sciurid having generalized Otospermophilus-like dentition, probably an unknown North American member of stem Marmotina.

Fossil man. Human paleontology, Paleontology
DOAJ Open Access 2019
Like phoenix from the ashes: How modern baleen whales arose from a fossil “dark age”

Felix G. Marx, Erich M.G. Fitzgerald, R. Ewan Fordyce

The evolution of baleen whales (Mysticeti), the largest animals on Earth, was punctuated by a pivotal turnover event. Following their emergence around 36 million years (Ma), mysticetes diversified into a disparate range of toothed and toothless species until 23 Ma, but then nearly vanished from the global fossil record for the next five million years. Following this early Miocene “dark age”, toothless mysticetes spectacularly reappeared around 18–17 Ma, whereas toothed mysticetes had gone entirely extinct. Here, we suggest that this turnover event reflects a change in mysticete habitat occupancy. Using the well-sampled record of Australasia as a case study, we show that Oligocene pre-“dark age” mysticetes formed distinct coastal and offshore assemblages, dominated by small (2–4 m), ecologically disparate toothed species, and larger (5–6 m) toothless filter feeders, respectively. Environmental change around the Oligocene–Miocene boundary led to the decline of the endemic coastal assemblages, leaving nearshore deposits virtually devoid of mysticetes. Filter feeders persisted offshore and subsequently re-invaded coastal habitats during the mid-Miocene Climatic Optimum, thus establishing the modern, cosmopolitan mysticete fauna.

Fossil man. Human paleontology, Paleontology
S2 Open Access 2018
Bracketing phenotypic limits of mammalian hybridization

Y. Savriama, Mia Valtonen, Juhana I. Kammonen et al.

An increasing number of mammalian species have been shown to have a history of hybridization and introgression based on genetic analyses. Only relatively few fossils, however, preserve genetic material and morphology must be used to identify the species and determine whether morphologically intermediate fossils could represent hybrids. Because dental and cranial fossils are typically the key body parts studied in mammalian paleontology, here we bracket the potential for phenotypically extreme hybridizations by examining uniquely preserved cranio-dental material of a captive hybrid between gray and ringed seals. We analyzed how distinct these species are genetically and morphologically, how easy it is to identify the hybrids using morphology, and whether comparable hybridizations happen in the wild. We show that the genetic distance between these species is more than twice the modern human-Neanderthal distance, but still within that of morphologically similar species-pairs known to hybridize. In contrast, morphological and developmental analyses show gray and ringed seals to be highly disparate, and that the hybrid is a predictable intermediate. Genetic analyses of the parent populations reveal introgression in the wild, suggesting that gray-ringed seal hybridization is not limited to captivity. Taken together, gray and ringed seals appear to be in an adaptive radiation phase of evolution, showing large morphological differences relative to their comparatively modest genetic distance. Because morphological similarity does not always correlate with genetic distance in nature, we postulate that there is considerable potential for mammalian hybridization between phenotypically disparate taxa.

2 sitasi en Biology
S2 Open Access 2016
La paleontología de los vertebrados en Argentina desde la segunda mitad del siglo XX hasta nuestros días: un estudio cuali-cuantitativo basado en Ameghiniana

E. Jaureguizar, P. Posadas, S. Miguel et al.

The aim of this paper is to analyze the evolution of vertebrate paleontology in Argentina based on the journal Ameghiniana . Using all documents on vertebrate paleontology published in this journal during 1957-2014, items such as the number of paper published, the number of signatures (total and by paper), the percentage of man and woman authorships, first authors place of residence, the geographic and stratigraphic origin of fossils, and topics considered were analyzed. A total of 668 documents were included in the study. The results show an increasing trend in the number of documents and signatures per document along the span considered (the latter mainly from the ´80s to present day). Also, there is an increase in the number of man and woman authorships, in an even masculinized discipline but showing a promising trend towards gender parity/equality. There is a predominance of single and double authorships, and most contributions have Argentinian paleontologists as first authors (especially from La Plata). Regarding the stratigraphic origin, most papers are devoted to Cenozoic, and to the Neogene within it.  When main topics are considered, taxonomy papers predominate. Mammals (especially rodents and xenarthrans) followed by reptiles (particularly dinosaurs) are the most studied taxa. Fossils studied come mainly from Argentina (especially, from Patagonia, followed by those of the Pampean region). The results obtained are explained in the historical context in which the discipline has developed in Argentina.

2 sitasi en Geography, Art

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