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In this paper we describe a new lizard from the early Eocene of the Cos locality in the Quercy region (near the Caylus village, Southwest France). The age of the Cos deposit has been proposed as the MP 10-11 interval, close to the transition of the late Ypresian to early Lutetian. The fossil material includes a nearly complete right maxilla and a large section of the right dentary, both elements attributed to Pan-Gekkota. These specimens are morphologically different from crown gekkotans, therefore, we describe them as a new species. Some aspects of the maxilla are very atypical regarding geckos (e.g., the shape of the facial process). The posterior margin of the facial process slopes down gradually dorsoventrally towards the jugal facet, reaching the posterior end of the maxilla, in contrast to gekkotans, where the facial process ends anterior to the posterior end of the maxilla. A similar maxilla is present in the Late Jurassic-Early Cretaceous pan-gekkotan genus Eichstaettisaurus. This suggests that the new fossil taxon represents either a lineage that persisted from the Mesozoic to the early Eocene in Europe, or perhaps a morphology otherwise unrepresented in crown gekkotans. We allocate this taxon provisionally to Pan-Gekkota, and contribute to increase the diversity of this clade in Western Europe during the Paleogene, which now includes the stratigraphically similarly aged Laonogekko lefevrei from France (MP 10), and older Dollogekko from Belgium (MP 7). [ABSTRACT FROM AUTHOR]

In this paper, we present a detailed survey on the rodent fauna from the site of Barranco de los Conejos (Guadix-Baza Basin, southern Spain). Its rodent fauna is composed of three arvicolines (Orcemys giberti, Manchenomys oswaldoreigi, and Tibericola vandermeuleni) and two murids (Castillomys rivas and Apodemus atavus). The three arvicoline species present ever-growing molars. Orcemys giberti and Manchenomys oswaldoreigi can be considered as descendants of local Mimomys species (Mimomys medasensis and Mimomys tornensis, respectively), while Tibericola vandermeuleni is an eastern inmigrant. Loosening of roots in Orcemys giberti and Manchenomys oswaldoreigi is explained as an adaptation to a fossorial way of life, in relation to the Early Pleistocene glacial-interglacial dynamics, which led to cooler and drier conditions. This environmental change would also explain the dispersal of Tibericola from the eastern Mediterranean. [ABSTRACT FROM AUTHOR]

Sarcopterygian remains are relatively common in the so-called "Placoderm Sandstone" (storm-origin bone-bearing breccia) from the Emsian (Lower Devonian) of Podlazie in the Holy Cross Mountains (Poland). Previous studies have mainly referenced the presence of dipnomorphs, chiefly portrayed by porolepiforms and occurrences of dipnoans. Porolepiforms are represented by Porolepis ex gr. P. posnaniensis, based on scales, skull and shoulder-girdle elements, whereas other remains have been attributed to Heimenia sp. The aim of this paper is to present the most detailed description of the porolepiforms and other sarcopterygian fishes from the "Placoderm Sandstone" from the Holy Cross Mountains since 1960s. Here, I present a new study based on more than 200 specimens, using both microtomographic (CT-scan) and silicon casts analyses, which indicate that not two, but at least three different taxa of sarcopterygians occur in the "Placoderm Sandstone" from Podlazie. The new data presented herein depict a more diversified assemblage of sarcopterygians in the marginal-marine environment of the Lower Devonian of the Holy Cross Mountains than previously thought, and shed a new light on sarcopterygian diversity along the shores of the Old-Red continent. [ABSTRACT FROM AUTHOR]

Among the great diversity of Oligocene mammals from Quebrada Fiera (Mendoza Province, Argentina), three families of typotherian notoungulates are very abundant. Since the first paper on archaeohyracids in 2010 until the last fieldwork in 2016, numerous unpublished remains were added to the collection. The study of all these remains, together with some revised materials, allows us to provide new anatomical data and some taxonomic decisions on these groups. Within Hegetotheriidae, we present one of the most complete skulls of "Prohegetotherium schiaffinoi" known to date, providing descriptions of certain previously unknown features of the caudal cranium; MCNAM-PV 3984 is discarded as belonging to Hegetotheriopsis sulcatus, as recently suggested, and is considered as Hegetotheriinae indet., like other isolated large specimens and some teeth previously determined as Prohegetotherium sp.; and several well-preserved specimens add to the sample of the pachyrukhine Prosotherium garzoni, including a partial maxilla with erupting P2. Concerning "Archaeohyracidae", Archaeohyrax suniensis is now better represented, recording several ontogenetic stages previously observed in the Bolivian sample of this species. Finally, within Interatheriidae, most new dental material belongs to Argyrohyrax proavus, but an isolated upper molar suggests the presence of a different Interatheriinae at Quebrada Fiera, more similar to the Bolivian Brucemacfaddenia boliviensis than to other Deseadan (late Oligocene) taxa. [ABSTRACT FROM AUTHOR]

Stable isotope analysis is pivotal for investigating the paleodiet and paleoecology of past mammals. In this paper, we analyzed thirty fossil enamel samples belonging to the families Suidae, Rhinocerotidae, and Deinotheriidae for δ13Cenamel and δ18Oenamel composition to investigate paleodiet and paleoecology of middle Miocene mammals of the Siwalik sub-Group of Pakistan. The three mammalian groups, when combined together, yielded an average δ13Cenamel value of -12.2 ± 2‰, indicating a pure to nearly pure C3 diet. Suids show slightly higher δ13Cenamel values of -11.2 ± 1.4‰ when compared to rhinocerotids and deinotheres (-12.3 ± 0.8‰ and -12.5 ± 1.3‰, respectively), which could be explained by selective foraging on new leaf shoots or feeding from open spaces. Alternatively, the differences in δ13Cenamel could be due to different digestive physiologies and different enamel-diet enrichment factors. Members of all three families showed significant differences in δ18Oenamel values, where suids yielded higher δ18O values of -8.2 ± 1.2‰ compared to rhinocerotids and deinotheres (-11.4 ± 1.8‰ and -10.4 ± 1.7‰, respectively). Based upon these results, we assume that these mammals inhabited subtropical forests similar that of mid-Miocene of the Siwalik Group, India and Nepal. The modern analogues of such vegetation system are present in East and South of Myanmar, Nepal, and Malaya where precipitation is enough to support evergreen C3 forests. By contrast, today's floodplain environments in Pakistan are dominated by C4 grasses, and C3 vegetation is only present in non-floodplain settings. [ABSTRACT FROM AUTHOR]

This paper describes a petrified trunk collected from a conglomerate bed of the Springhill Formation (Berriasian-Valanginian) in the Estancia El Álamo locality, Santa Cruz Province, Argentina. The fossil trunk is classified within the ubiquitous genus Agathoxylon and the wood anatomy shows a close affinity to that of Araucariaceae. This Patagonian wood has a distinct combination of anatomical characteristics unique among all known species from the Jurassic and Cretaceous of Western Gondwana allowing to diagnose a new fossil taxon Agathoxylon mendezii sp. nov. Sedimentological and megafloristic proxies of the Springhill Formation suggest that Agathoxylon mendezii sp. nov. grew under a warm and wet climate, which indicates a subtropical to temperate palaeoenvironment. However, the large number of frost rings in the earlywood of this araucarian tree suggests that the palaeoenvironment at Estancia El Álamo was subjected to recurrent disturbances, most likely caused by regional continuous volcanic activity originating from volcanoes located far away to the west. This activity would have produced periodic stratospheric veils that promoted rapid decreases in surface air temperature; the wood response to such stressful conditions would have been the formation of numerous (at least five) frost rings. Although recurrent eruptions in Patagonia during the Early Cretaceous are well recorded, this study is the first to register eruptions recorded in a coniferous wood. [ABSTRACT FROM AUTHOR]

This paper describes a sclerobiont association from the Paso Hondo Formation (Roadian, middle Permian), Chiapas, Mexico. Different marine invertebrates such as hederelloids, microconchids, bryozoans, and crinoids (represented by holdfasts) encrusted brachiopod shells belonging to Athyridida and Rhynchonellida. This association is similar to those recorded in different Devonian localities, especially by the co-occurrence of microconchids, hederelloids, and bryozoans. Paleoecological analysis revealed that bryozoans were the most abundant sclerobionts, whereas crinoid holdfasts were uncommon. Likewise, hederelloids and microconchids often settled on hosts previously colonized by bryozoans. Most microconchids encrusted rhynchonellid shells. A positive correlation between the size of the hosts and abundance/diversity of sclerobionts was recorded. The distribution analysis suggests that sclerobiont colonization could have been influenced either by inhalant currents of brachiopods, time of exposure, position of hosts, or by combination of all these factors. Moreover, most of commissures and foramens of brachiopods were not covered by epibionts, suggesting that there was a live interaction. Thus, studied brachiopods were likely encrusted syn vivo, and the interaction between sclerobionts and their brachiopod hosts was likely commensal since there is no damage to the brachiopod valves in the form of malformations or borings. On the contrary, the epibiont cover might have served as a natural shield against predators and parasites. The Roadian age of the association is based on the stratigraphic distribution of host brachiopods. The studied association inhabited open waters on a homoclinal carbonate ramp in the Chicomuselo region. Although encrusted brachiopods belong to the biotic Grandian Province, similar sclerobiont communities have not been previously recorded from the Permian of North America or beyond. The described community represents the youngest record of co-occurring microconchids, hederelloids, and bryozoans, as all previously known similar communities originate from the Late Devonian. [ABSTRACT FROM AUTHOR]

Soritids are a successful group of larger Foraminifera with several extant representatives that display a complex alternation of generations, the so-called paratrimorphic life cycle. Fossil soritids are abundantly widespread through the geological record starting from the Albian. The oldest Soritidae possessing annular chambers and cross-wise oblique chamber communications is represented by the Paleocene species Mardinella daviesi. The present paper provides a description of the morphology and anatomy of the three reproductive generations recovered in a Mardinella-rich assemblage from a lower Paleogene shallow-water carbonate succession in SW Iran (Zagros Zone). Comparison among proportion of schizonts vs. gamonts with extant soritids shows that there is an easy match. This would confirm that the paratrimorphic life cycle was successfully adopted by the early soritids to maintain fitness with the environment and to keep a stable mutual relationship with a certain group of endosymbionts. [ABSTRACT FROM AUTHOR]

Despite being reported from various localities and stratigraphic intervals, knowledge of the siliceous sponges from the Cenozoic of Eastern Europe remains surprisingly limited. Studies assessing their diversity are almost exclusively in Russian and rather hard to obtain. The most comprehensive elaboration of the sponge spicules from the Paleogene of the East European Platform was published in 2003 and deals with material from Ukraine, Russia, Belarus, and Lithuania. However, the classification in that paper is purely artificial and extremely difficult to interpret according to modern biological criteria. A reassessment of this material is carried out, with the aim of revising all morphotypes of spicules, and identifying them to the lowest possible taxonomic level. Results suggest that the assemblage is much more diverse than previously thought, including members of 24 demosponge families (class Demospongiae), one homoscleromorph (class Homoscleromorpha), and at least one hexactinellid (class Hexactinellida). Our improved understanding of the diversity of Paleogene sponge fauna of the East European Platform will have implications for the interpretation of the past and future ecological and paleobiogeographic studies. [ABSTRACT FROM AUTHOR]

This article is a memorial tribute to Aleksander Nowiński, a prominent paleontologist who passed away in 2023. Nowiński was born in 1935 in Rypin, Poland, and developed a fascination with optics and machines from a young age. He went on to study geology at Warsaw University and became a member of Polish-Mongolian Paleontological expeditions, where he described a new species of sauropod dinosaur. Later in his career, Nowiński focused on tabulate corals, publishing several monographs and papers on their taxonomy and growth patterns. He was known for his meticulous and precise work, as well as his love for classical music. Nowiński retired in 2003 and lived in his hometown until his death in 2023. [Extracted from the article]

Rebbachisaurids are a group of basal diplodocimorph sauropods that diversified in Gondwana at the end of the Early Cretaceous and the beginning of the Late Cretaceous. It is a group of great palaeobiogeographical interest, for it clearly illustrates various processes of dispersal throughout Gondwana and to Laurasia prior to the breakup of Africa and South America. However, the relationships within the group are still under discussion owing to the scarcity of cranial material that would help clarify them. In the present paper we describe the new rebbachisaurid Lavocatisaurus agrioensis gen. et sp. nov. from the Aptian-Albian (Lower Cretaceous) of Neuquén (Argentina). Remains have been recovered belonging to an adult specimen (holotype) and two immature specimens (paratypes). Taken together, almost all the bones of the taxon are represented, including most of the cranium. Lavocatisaurus agrioensis gen. et sp. nov. is the first rebbachisaurid from Argentina with an almost complete cranium, making it possible to recognize differences with respect to other rebbachisaurids, such as the highly derived Nigersaurus. Among its most notable characters are the presences of a large preantorbital fenestra and maxillary teeth that are significantly larger than those of the dentary. Our phylogenetic study places Lavocatisaurus amongst basal rebbachisaurids, as the sister lineage to Khebbashia (the clade formed by Limaysaurinae + Rebbachisaurinae). This position, which is somewhat more derived than that previously suggested for Comahuesaurus and Zapalasaurus (the Argentinean rebbachisaurids closest in geographical and geological terms), reaffirms the presence of different basal rebbachisaurid lineages in the Early Cretaceous of Patagonia. [ABSTRACT FROM AUTHOR]

This paper summarizes knowledge on the Neogene-Quaternary terrestrial fossil record from the Middle Kura Basin accumulated over a century and aims to its integration into the current research. This fossil evidence is essential in understanding the evolution of the Eurasian biome, since this territory is located at the border of Eastern Mediterranean and Central Asian regions. The general biostratigraphic framework suggests existence of two major intervals of the terrestrial fossil record in the area, spanning ca. 10-7 Ma and ca. 3-1 Ma, and points to an important hiatus between the late Miocene and late Pliocene. General aspects of the paleogeographic history and fossil record suggest that the biogeographic role of the Middle Kura Basin has been changing over geological time from a refugium (Khersonian) to a full-fledged part of the Greco-Iranian province (Meotian-Pontian). The dynamic environmental changes during the Quaternary do not depict this territory as a refugium in its general sense. The greatest value of this fossil record is the potential to understand a detailed history of terrestrial life during demise of late Miocene Hominoidea in Eurasia and early Homo dispersal out of Africa. Late Miocene record of the Middle Kura Basin captures the latest stage of the Eastern Paratethys regression, and among other fossils counts the latest and the easternmost occurence of dryopithecine, Udabnopithecus garedziensis, while the almost uninterrupted fossil record of the late Pliocene-Early Pleistocene covers the time interval of the early human occupation of Caucasus and Eurasia. [ABSTRACT FROM AUTHOR]

The Paleogene was a time of high diversity for snakes, and was characterized by some of the largest species known to have existed. Among these snakes were pan-Tethyan marine species of Nigerophiidae and Palaeophiidae. The latter family included the largest sea snake, Palaeophis colossaeus, known from the Trans-Saharan Seaway of Mali during the Eocene. This paper describes new material collected from Malian Trans-Saharan Seaway deposits, including additional material of Palaeophis colossaeus, a new, large species of nigerophiid, Amananulam sanogoi gen. et sp. nov., and a medium-sized snake of indeterminate affinities. The material provides new information on the intracolumnar variation of the vertebral column in Palaeophis colossaeus. We estimate the total length of each species by regression of vertebral measurements on body size. Both Palaeophis colossaeus and Amananulam sanogoi gen. et sp. nov. are the largest or among the largest members of their respective clades. The large size of Tethyan snakes may be indicative of higher temperatures in the tropics than are present today. [ABSTRACT FROM AUTHOR]

The family Cantharidae is a worldwide distributed group of flattened and soft-bodied beetles displaying aposematic colouration. These beetles, commonly known as soldier beetles, have an extensive fossil record dating back to the Lower Cretaceous. The majority of fossil material, referred to Cantharidae, is known from amber inclusions. In this paper we describe and illustrate a new soldier beetle Kuskaella macro ptera gen. et sp. nov. from the Baltic amber. It is characterised by pronotum of the male parallel-sided in basal third and abruptly narrowed towards apex, and of the female gradually and steadily narrowing from the basal margin to the apex; globular head; unequal maxillary palpomeres with the last segment elongated-globular and pointed; long elytra slightly surpassing the last abdominal segment. This finding is the first described species of both sexes preserved in a single amber piece. [ABSTRACT FROM AUTHOR]

Neuquenraptor argentinus was described as the first undoubted deinonychosaurian theropod from Gondwana. The only known specimen is represented by a fragmentary skeleton, including a nearly complete foot, coming from Late Cretaceous beds of Neuquén Province, Patagonia, Argentina. Neuquenraptor was later considered as belonging to the Southern Hemisphere paravian clade Unenlagiidae, and proposed as a junior synonym of Unenlagia comahuensis. The aim of the present paper is to include a detailed anatomical description of Neuquenraptor (up to the date only known by a preliminary description). Comparisons with other paravians, especially unenlagiids, resulted in the finding of characters that may be considered as diagnostic of Unenlagiidae (e.g., scar-like fourth trochanter of femur, metatarsal II with tongue-shaped process over the caudal surface of metatarsal III, well-developed convex longitudinal plantar crest of metatarsal IV). Furthermore, comparisons between Neuquenraptor and Unenlagia are carried out with the aim to evaluate the possible synonymy between these taxa. These comparisons indicate that at least two similar-sized unenlagiids were present on the Portezuelo Formation. However, in concordance with previous authors, we are not able to support nor dismiss the possible synonymy between Unenlagia and Neuquenraptor. Additional findings of unenlagiid fossils from the Portezulo Formation will help to clarify the taxonomic status of these taxa. [ABSTRACT FROM AUTHOR]

The megamouth shark (Lamniformes: Megachasmidae) has sporadic occurrences both in the present-day oceans and in the fossil record. In this paper, we describe a new megachasmid, Megachasma alisonae sp. nov., on the basis of a morphologically distinct tooth collected from the Pyt Member of the late Eocene Søvind Marl Formation at Moesgård Strand in Denmark, that represents the geologically oldest known Megachasma. The tooth likely came from an individual that measured somewhere between 1.3 and 3.5 m long, and its morphology and chipped cusp tips suggest that it possibly fed on macro-zooplankton and small fishes that had hard skeletal components. Its occurrence in the mid-Priabonian Pyt Member at least suggests that the shark inhabited a relatively deep, open marine environment about 36 Ma ago. This Eocene specimen is significant because it illustrates the dental condition of early megachasmids, which is distinctively odontaspidid-like morphologically. [ABSTRACT FROM AUTHOR]

This paper reports the use of FEA (Finite Element Analysis) to model dinosaur tracks. Satisfactory reproductions of sauropod ichnites were simulated using 3D numerical models of the elasto-plastic behaviour of soils. Though the modelling was done of ichnites in situ at the Miraflores I tracksite (Soria, Spain), the methodology could be applied to other tracksites to improve their ichnological interpretation and better understand how the type and state of the trodden sediment at the moment the track is created is a fundamental determinant of the morphology of the ichnite. The results obtained explain why the initial and commonly adopted hypothesis-that soft sediments become progressively more rigid and resistant at depth-is not appropriate at this tracksite. We explain why it is essential to consider a more rigid superficial layer (caused by desiccation) overlying a softer layer that is extruded to form a displacement rim. Adult sauropods left trackways behind them. These tracks could be filled up with water due to phreatic level was close to the ground surface. The simulation provides us with a means to explain the differences between similar tracks (of different depths; with or without displacement rims) in the various stratigraphic layers of the tracksite and to explain why temporary and variable conditions of humidity lead to these differences in the tracks. The simulations also demonstrate that track depth alone is insufficient to differentiate true tracks from undertracks and that other discrimination criteria need to be taken into account. The scarcity of baby sauropod tracks is explained because they are shallow and easily eroded. [ABSTRACT FROM AUTHOR]

The dinosaur record in the South Pyrenees Basin is diverse and rich. A total of 142 theropod teeth were studied for this paper, which constitutes one of the richest samples for these remains in Europe. Eight upper Campanian to upper Maastrichtian outcrops from the Pyrenees produced six non-avian theropod taxa (Theropoda indet., Coelurosauria indet., ?Richardoestesia, ?Dromaeosauridae indet., ?Pyroraptor olympius, ?Paronychodon). These six taxa are added to two previously described theropods (a Richardoestesia-like form and a possible ornithomimosaurid), indicating that there was considerable theropod diversity on the Iberian Peninsula during the Late Cretaceous. [ABSTRACT FROM AUTHOR]

In this paper, we describe a previously unknown species of the glirid Eliomys from the Late Miocene and Early Pliocene Cabriel, Alcoy and Granada basins of southeastern Spain. Eliomys yevesi sp. nov. is characterized by its relative small size, narrow lingual wall and common presence of two centrolophs in the upper molars, and well-developed centrolophids in the lower molars. The new species is the probable ancestor of E. intermedius, which in turn represents the ancestor of the extant E. quercinus. According to its morphologic and biometric features, the origin of E. yevesi sp. nov. is likely to be found in some population of E. truci from the Late Miocene. Based on these affinities, we propose the lineage E. truci-E. yevesi sp. nov.-E. intermedius-E. quercinus, in which there is a trend towards the development of centrolophs, as well as the reduction of accessory crests. [ABSTRACT FROM AUTHOR]

Early Jurassic aragonitic foraminifers are outstandingly well-preserved in the Marmorea crust, a multiphased ferromanganese layer limiting the Schnöll and Adnet formations (Adnet, Northern Calcareous Alps, Austria). This remarkable preservation, related to the pervasive impregnation of aragonitic tests prior to their recrystallization, allowed observing unknown diagnostic features of the genus Involutina, which typifies the Suborder Involutinina. Thanks to a detailed examination of the Adnet specimens, this paper clarifies the taxonomy, systematic position, and phylogeny of Involutina. A new diagnosis, structural model, and lineage are introduced for the group. Involutina is the direct descendant of Aulotortus and the two taxa probably showed a parallel evolution. As Aulotortus, Involutina presents a high intraspecific variability and its diversity must be revised downward. Current phylogenetic and taxonomic frames of the Suborder Involutinina are firmly questioned as, contrary to previous schemes, the type-genus possesses more than one lamellar deposit per whorl. In Involutina, the height and distribution of papillae on the test surface is not random and probably related to a biological function. We here propose that the papillose lamellae and tube infoldings that characterize representatives of the genus were rudimentary features for light catching and symbiont positioning, respectively. [ABSTRACT FROM AUTHOR]

South American Mesozoic snake diversity is mostly represented by genera from the Cenomanian (Najash), Santonian--Campanian (Dinilysia), and Campanian--Maastrichtian (Alamitophis, Patagoniophis, Rionegrophis, and Australophis) of Patagonia, Argentina. In this paper, we describe a new snake genus and species, Seismophis septentrionalis, from the Cenomanian (early Late Cretaceous) of the Alcântara Formation, Maranhão, northeastern Brazil. The new snake comprises a posteriormost trunk vertebra and possibly a poorly preserved midtrunk vertebra. Both vertebrae share small size, zygosphene moderately thick with a rectilinear roof, absence of paracotylar foramina, presence of parazygantral foramina, and strongly marked parasagittal ridges of the neural arch. The new snake is here considered of uncertain systematic affinities, but probably close to the limbed snake Najash rionegrina. Although the material is very fragmentary and the systematic assignment is still unresolved, this snake represents the oldest, as well as probably the most primitive snake from Brazil. [ABSTRACT FROM AUTHOR]

This paper presents the results of analysis of the Miocene woods collected from three sampling sites in the Polish part of the Carpathian Foredeep. The location in the stratigraphic profile and the state of fossil preservation indicate that the woods were transported by waters flowing from highland or from mountainous regions and then deposited and fossilised in delta areas. Fragments of 16 lignified or silicified woods were collected for anatomical research. The fossil woods were classified as Piceoxylon piceae, Juniperoxylon pachyderma, Cupressinoxylon canadense and Cupressinoxylon polonicum. Disturbance zones observed in Cupressinoxylon polonicum are interpreted as frost rings. Frost rings suggest that despite the documented existence of warm and humid climatic conditions during the Miocene period, the temperatures in mountainous areas could temporarily drop below freezing point. [ABSTRACT FROM AUTHOR]

In this paper well-preserved isoetalean microsporophyll, containing in situ microspores, is described from the uppermost part of the Utrillas Formation (latest Albian) in Teruel Province, northeastern Spain. Similar but dispersed microspores were described previously as Peromonolites. Fossil plant impressions and compressions including the sporophyll lamina and micro sporangium are referred to the fossil genus Isoetites. Although Isoetes-like megafossil remains, often with in situ or associated megaspores, are known from quite a few Cretaceous sites, and dispersed microspores are known, the presence of intact microsporangia is rare. Herein we suggest that microsporangia may have dispersed in masses, possibly representing a new unknown strategy in microspore dispersal in this group of plants. [ABSTRACT FROM AUTHOR]

Understanding ontogenetic variation is fundamental for adequate species definition and is the key for recognizing evolutionary relevant processes like heterochrony or developmental constraints. The larval and post-larval shell ontogeny and the ecology of the trigoniide bivalve Myophorella garatei are described in this paper. The species occurs in offshore transition facies of the late Valanginian Pilmatué Member of the Agrio Formation in the Neuquén Basin, Argentina. The larval shell has a rather small prodissoconch I; and if prodissoconch II is present, it is rather weakly developed. From these data, a larval stage of low dispersal capability is inferred for Myophorella garatei, either short-lived planktotrophic or nonplanktotrophic. The study of post-larval development included general shell shape and ornamentation. To assess general shell shape a geometric morphometric analysis was performed on the lateral view, together with a study of allometry for the shell width. As a result, two main allometric stages of development could be identified. During the first stage a relative size reduction of the area co-occurs with a slight elongation of the shell, while the second stage is marked by dorsal bending of the shell and an increase on relative width. Ornamentation was examined qualitatively, but also a geometric morphometric analysis was performed on the flank costae. The first two flank costae are subconcentric; from the third costa onwards they become oblique, intially changing from more curved to less curved shapes, while on a third stage they show the opposite trend. Finally, a general interpretation of the adaptive morphology of adult shell was performed, concluding that M. garatei was adapted to low energy, soft bottom environments, and probably lived with the posterior straight margin levelled at the water-sediment interface. [ABSTRACT FROM AUTHOR]

Brain endocasts are rare in the fossil record because they are only preserved under exceptional conditions. An equid brain endocast from the early Pleistocene of Wanrong County, Shanxi Province, China, is reported in this paper. Measuring approximately 140 x 95.2 x 83 mm, the new specimen represents a relatively advanced adult horse brain. Comparisons indicate that it is more derived than those of Hyracotherium andMesohippus in having an expanded neocortex, and more than those ofPliohippus and Hipparion in having an enlarged network of branching sulci; in most characters involving these sulci, the Shanxi brain conforms to the extant species Equus caballus. The sulcus diagonalis of the Equus brain appears to have evolved conservatively during the early Pleistocene, whereas the sulcus suprasylvius seems to have evolved rapidly. The specimen demonstrates that the development of a high degree of complexity predates the enlargement of the brain in the horse, which increased in length, breadth, and especially height during the late Cenozoic. [ABSTRACT FROM AUTHOR]

This paper presents the results of analysis of the Miocene woods collected from three sampling sites in the Polish part of the Carpathian Foredeep. The location in the stratigraphic profile and the state of fossil preservation indicate that the woods were transported by waters flowing from highland or from mountainous regions and then deposited and fossilised in delta areas. Fragments of 16 lignified or silicified woods were collected for anatomical research. The fossil woods were classified as Piceoxylon piceae, Juniperoxylon pachyderma, Cupressinoxylon canadense and Cupressinoxylon poloni-cum. Disturbance zones observed in Cupressinoxylon polonicum are interpreted as frost rings. Frost rings suggest that despite the documented existence of warm and humid climatic conditions during the Miocene period, the temperatures in mountainous areas could temporarily drop below freezing point. [ABSTRACT FROM AUTHOR]

South American Mesozoic snake diversity is mostly represented by genera from the Cenomanian (Najash), Santonian-Campanian (Dinilysia), and Campanian-Maastrichtian (Alamitophis, Patagoniophis, Rionegrophis, and Australophis) of Patagonia, Argentina. In this paper, we describe a new snake genus and species, Seismophis septentrionalis, from the Cenomanian (early Late Cretaceous) of the Alcântara Formation, Maranhão, northeastern Brazil. The new snake comprises a posteriormost trunk vertebra and possibly a poorly preserved midtrunk vertebra. Both vertebrae share small size, zygosphene moderately thick with a rectilinear roof, absence of paracotylar foramina, presence of parazygantral foramina, and strongly marked parasagittal ridges of the neural arch. The new snake is here considered of uncertain sys-tematic affinities, but probably close to the limbed snake Najash rionegrina. Although the material is very fragmentary and the systematic assignment is still unresolved, this snake represents the oldest, as well as probably the most primitive snake from Brazil. [ABSTRACT FROM AUTHOR]

This paper discusses the phyletic interpretation of the genus Phricodoceras and its taxonomic classification at the subfamily, family, and superfamily levels from an historical and critical perspective. First a review of the latest findings on this taxon is presented and the grounds for the attribution of Phricodoceras to the Schlotheimiidae (Psiloceratoidea) are summarized and illustrated. This review is a synthesis grounded on evolutionary (e.g., heterochronies, innovations), eco-ethological (e.g., assumed shell hydrodynamic capacities) and spatio-temporal patterns (e.g., bio-chronostratigraphy, palaeobiogeography). Then, the main stages of understanding the taxonomy of Phricodoceras since the early nineteenth century are reviewed. Two main taxonomic concepts alternate over time. The first is based on the "overall resemblance" of Phricodoceras to some coeval Eoderoceratoidea leading to the genus being included in its own family or subfamily (e.g., Phricodoceratinae) among the Eoderoceratoidea. The second hypothesis, recently confirmed by the discovery of an intermediate form (i.e., Angulaticeras spinosus), clearly includes Phricodoceras within the Schlotheimiidae (Psiloceratoidea). Comparison of these two very different conceptions reveals how "overall resemblance" can be misleading and shows that the discovery of intermediate forms is often the key to phyletic reconstructions in ammonites. [ABSTRACT FROM AUTHOR]

The Late Triassic was a time of pronounced radiation in several groups of foraminifers. The rapid evolutionary processes in the Suborder Involutinina caused particularly high diversification of these aragonitic foraminifers, which became a key group for Upper Triassic biostratigraphy. Among them, Triasina hantkeni and Triasina oberhauseri are regarded as the most precise guide fossils. However, while these species are widely used, a poor documentation of the detailed test structure of T. oberhauseri has resulted in misidentifications. The exceptional preservation and abundance of Triasina oberhauseri in the Upper Triassic deposits of the Black Marble Quarry (Wallowa terrane, Oregon, USA) has allowed us to make the first detailed observations of its coiling, innermost structure and lamellae arrangement and to recognize morphological features that were either wrongly interpreted or not described in the original systematic definition of the species. In this paper, we demonstrate that the species possesses characteristics that hamper its assignment to Triasina and we propose a new genus, Aulosina, to accommodate this taxon. Placing emphasis on the accuracy of the morphological description, the diagnosis and the systematic definition of the species are here improved. The identification of innovative features in Aulosina oberhauseri (strengthenings, shortened lamellae) highlights new evolutionary trends for the lineage of Involutinina that have proved useful for the establishment of phylogenetic links between involutinid genera and for understanding the evolutive steps leading to the formation of inner-pillars in tubular foraminifers. The increasing complexity of Involutinina representatives at the end of the Triassic, notably marked by the appearance of internal structures in Triasininae, leads us to regard them as probable symbiont-bearing foraminifers. [ABSTRACT FROM AUTHOR]

In this paper,we report on abundant fossils of Platybelodon from the Middle Miocene of the Linxia Basin, China. Most of the fossils were discovered at two localities (Laogou and Zengjia) in the upper Middle Miocene Hujialiang Formation, and possess derived characters for the genus, including a relatively slender upper incisor, the development of a transverse ledge on the narrowest part of the mandibular symphysis, narrow, elongate and hypsodont third molars, the development of fourth loph(id)s on the second molars, and the development of small enamel conules and cementum in the interloph(id)s. Following comparisons with other Eurasian platybelodonts, we assign these remains to Platybelodon grangeri, and demonstrate that they are morphologically intermediate between P. grangeri from the Tunggurian localities of Tarim Nor and Platybelodon Quarry in Inner Mongolia. We suggest that the locality of Laogou may be younger than that of Zengjia, based on the occurrence of platybelodonts showing a suite of more derived characters. In addition, we assign two further specimens of Platybelodon from the lower Middle Miocene Dongxiang Formation of the Linxia Basin to Platybelodon danovi, owing to their retention of plesiomorphic characters distinguishing them from other Linxia Platybelodon fossils. Based on a cladistic analysis, we propose an evolutionary sequence of platybelodonts in Eurasia, and discuss potential functional adaptations. [ABSTRACT FROM AUTHOR]

In the classic section across the Silurian-Devonian boundary at Dnistrove (Podolia, Ukraine) the brachiopod fauna has never been studied in detail. This paper presents results of research on brachiopods from this important locality and time interval. Bed-by-bed collecting has enabled the detailed distribution of brachiopod taxa through the boundary beds to be revealed. Generally, the reference section at Dnistrove yields rather scarce but often well preserved brachiopods. Dayia bohemica and Dnestrina gutta can be regarded as characteristic species for the uppermost Silurian. A relatively high-diversity but low-abundance brachiopod fauna occurs in the lowest 1.8 m of the earliest Devonian. Only three forms have been found to cross the Silurian-Devonian boundary: the strophomenide Plectodonta (Plectodonta) mariae pantherae subsp. nov., the atrypide Gracianella (Sublepida) paulula sp. nov., and the spiriferide Howellella (Howellella) latisinuata. A relatively narrow brachiopod-rich interval at 5.5mabove the Silurian-Devonian boundary yields 16 brachiopod species which probably indicate a setting near the lower limit of the photic zone equivalent to the Benthic Assemblage 3-4 boundary. Two new species and one new subspecies are described: Skenidioides tatyanae, Plectodonta (Plectodonta) mariae pantherae, and Gracianella (Sublepida) paulula. [ABSTRACT FROM AUTHOR]

The present paper focuses on the evolutionary dynamics of ammonites from sections along the Russian Pacific coast during the mid- and Late Cretaceous. Changes in ammonite diversity (i.e., disappearance [extinction or emigration], appearance [origination or immigration], and total number of species present) constitute the basis for the identification of the main bio-events. The regional diversity curve reflects all global mass extinctions, faunal turnovers, and radiations. In the case of the Pacific coastal regions, such bio-events (which are comparatively easily recognised and have been described in detail), rather than first or last appearance datums of index species, should be used for global correlation. This is because of the high degree of endemism and provinciality of Cretaceous macrofaunas from the Pacific region in general and of ammonites in particular. [ABSTRACT FROM AUTHOR]

The paper focuses on patterns of the evolution of the simplest and longest-ranging (approximately 18 Ma) Silurian graptolite Pristiograptus dubius. The Pristiograptus dubius species group consists of the P. dubius stem lineage represented by a sequence of a number of subspecies displaying only small morphological changes as well as derivative species produced from the stem lineage by means of iterative speciation. This long raging graptolite lineage is the only one, apart of one retiolitid, which survived the most severe environmental event for graptolites, the Cyrtograptus lundgreni Event. Based on three-dimensional, isolated material two P. dubius groups taxa are distinguished. One group has an obtuse angle between the thecal lip and the succeeding thecal wall, the second group has a right or acute angle. Other characters differentiating P. dubius forms are: the shape of the apertural lips, differences in rhabdosome shape and size, and a different number of sicular rings. Sixteen species and subspecies of Pristiograptus from the East European Platform, Poland and Lithuania are discussed. Five new subspecies P. dubius magnus, P. dubius paezerensis, P. dubius praelodenicensis, P. dubius postfrequens, and P. dubius postmagnus are proposed. [ABSTRACT FROM AUTHOR]

In morphological studies the shape may be conveniently quantified by relative dimensions or dimensionless quantities. The analyses of shell morphology and morphospace occupation have been historically approached mainly by means of statistical analysis on classical dimensions (distance measurements: diameter, umbilical width, whorl width, whorl height and apertural whorl height), the Raup's coiling and expansion rate parameters and, more recently, by means of the ADA-model which conjugates the classical variables in a single simple equation. Relationships between these studies should be possible based on mathematical equivalences between classical dimensions and those of coiling and expansion rates. These equivalences, which are presented in this paper, have been obtained on the basis of the ADA-model and a new general method for deriving dimensionless models of morphology based on exponential trajectories as a function of a rotational angle. [ABSTRACT FROM AUTHOR]

An introduction to this issue of "Acta Palaentologica Polonica," focusing on the 30th anniversary of the 1980 "Science" paper about an iridium spike at the boundary between the Cretaceous and Paleogene periods in north-central Italy by Luis W. Alvarez, is presented.