Westernmost Occurrence Research Articles

New structural analysis in North Dobrogea - a key region to unravel the tectonics of the Black Sea back-arc basin during the Mesozoic

High-resolution structural analysis of stratigraphically-controlled units within North Dobrogea (ND), based on fieldwork and the production of new cross-sections as well as a reconstruction of the Mesozoic paleo-stress regimes, has resulted in a revision of the tectonic events across the region as well as demonstrating the significance of tectonic inheritance. The observed structures are closely related to the major strike-slip faults of the Teisseyre-Tornquist Zone (TTZ) a lithospheric structure active during the early and middle Mesozoic. The significance of this zone has been underestimated in previous kinematic reconstructions examining the opening of the continental back-arc basin of the Black Sea. Integrating the present results with existing knowledge on the tectonic evolution of the Black Sea, suggests a new conceptual kinematic model for further testing, one that involves movement of the continental fragment of Moesia NW along the TTZ during the early and middle Mesozoic. Such a displacement would represent the westernmost occurrence of the Cimmerian orogeny in the region of the western Black Sea. The escape of Moesia to the NW could possibly explain the polyphase extension of the western Black Sea crust, which developed on the continental Eurasian Plate as a back-arc basin due to the N-directed subduction of Tethys.

Petrografie a geochemie amfibolitů strážovského moldanubika

The amphibolites from the Strážov Moldanubian unit in western part of the Bohemian Massif form intercalations in metasediments of this geological unit. The Strážov Moldanubian unit forms the westernmost occurrence of Variegated group of the Moldanubian Zone. These amphibolites occur as intercalations of very different size in biotite-sillimanite, partly migmatitized paragneisses. The amphibolites were sampled in two abandoned quarries near the Svatá Kateřina and Běšiny. According to their modal composition the amphibolites occurring in quarry Radošín, near the Svatá Kateřina village, are plagioclase-bearing amphibolites with very high differences in amphibole and plagioclase ratio. The garnet is significant minor component of some amphibolites. The amphibolites occurring near of the Běšiny village form very thin, relatively long lenses as part of calc-silicate-amphibolite stromatites occurring in the central part of the Strážov Moldanubian unit. The both amphibolites are probably a metamorphic equivalent of tholeiitic volcanic rocks with tectonomagmatic features of the middle ocean ridge basalts (MORB).

A new species of Galene de Haan, 1833 (Galenidae: Brachyura) from the middle Miocene of Zagros Mountains, Iran.

A new species of Galene de Haan, 1833 (Decapoda: Brachyura: Galenidae) is described from the Mid Miocene (Langhian) strata of the Mishan Formation exposed at two localities in Hormozgan Province, Zagros Mountains, Iran. The galenid species, Galene dashtbani n. sp. is considered as the oldest representative of the genus and simultaneously the westernmost occurrence of all fossil and extant congeners known to date. The genus is currently limited to the Indo-West Pacific region. The present fossil occurrence of the genus suggests a Tethyan origin and subsequent migration eastward.

Cretaceous flora and fauna of the Sustut Group near the Sustut River, northern British Columbia, Canada

A partial ornithischian dinosaur skeleton discovered near the Sustut River in 1971 has, to date, represented the only vertebrate fossil remains recovered from the Sustut Basin in northern British Columbia, Canada, but the geological provenance and age of this specimen has remained unclear. We provide new data on the age of this dinosaur specimen based on reconnaissance palaeontological prospecting along the Sustut River, and also report new vertebrate and plant fossils from this region. A skeletal fragment of a species of the turtle Basilemys Hay, 1902 was discovered at a site closely matching field notes describing the initial collection of the ornithischian dinosaur, suggesting that the new turtle fossil derives from the same locality as the dinosaur. Palynomorphs collected from this site include the marker taxon Pseudoaquilapollenites bertillonites (Sriv.), found in the lower Hell Creek Formation, and suggesting an age range of between 68.2 and 67.2 Ma for the locality. To the west of this locality we discovered multiple new fossil plant sites preserving wood and the leaves of Metasequoia Miki and several angiosperms, and one site preserved fronds resembling a species of the tree fern Coniopteris Brong., suggesting a Cenomanian or older age for sites in the area. The complex translational history of the Intermontane Terrane means that the newly discovered turtle may not represent a northern range extension for Basilemys, but it does represent one of the westernmost occurrences of this genus. The discovery of new vertebrate fossil remains in a region with relatively little accessible outcrop at present indicates the potential for future discoveries in the higher elevation outcrops of the Sustut Basin in this mountainous region of British Columbia.

A collaborative approach to preparing for and reacting to emerald ash borer: a case study from Colorado

AbstractCollaboration has been the key to success for urban forest management in Colorado, not only collaboration amongst agencies at all levels of government but also in engaging industry allies, coordinating education and outreach efforts and in fostering community support. A unique interagency team, the Emerging Pests in Colorado (EPIC) Workgroup, was formed in 2009 to address the immediate threat from Thousand Cankers Disease (TCD) of walnut and to plan for the arrival of other invasive urban forest pests to Colorado. When the emerald ash borer (Agrilus planipennis Fairmaire) (EAB) was detected in Boulder, Colorado in 2013, it marked the westernmost occurrence of EAB in the US, threatening millions of planted and naturalized ash trees representing over 25 percent of the tree canopy throughout Colorado’s urban and riparian forests. The detection in Boulder prompted the development of a second multi-agency group, the Colorado EAB Response Team (CORT). The preparedness and established working relationships between stakeholders and responsible authorities allowed for a quick, decisive and unified response. We review as a case study: (1) the formation and history of collaborative interagency groups in Colorado; (2) how the interagency collaborative planning and post-detection EAB response have supported community forestry programmes throughout the state; (3) development of the post-detection EAB management plan and economics behind the strategy in Boulder, Colorado; and (4) the proactive EAB planning and outreach efforts underway in Denver, Colorado.

Winter temperature correlates with mtDNA genetic structure of yellow-necked mouse population in NE Poland.

We analysed a fragment (247 bp) of cytochrome b of mitochondrial DNA sequenced using 353 samples of yellow-necked mice Apodemus flavicollis trapped in seven forests and along three woodlot transects in north-eastern Poland. Our aims were to identify the phylogeographic pattern and mtDNA structure of the population and to evaluate the role of environmental conditions in shaping the spatial pattern of mtDNA diversity. We found out that three European haplogroups occurred sympatrically in north-eastern Poland. Inferences based on mtDNA haplotype distribution and frequency defined five subpopulations. The mtDNA-based structure of mice significantly correlated with winter temperature: frequency of Haplogroup 1 was positively, and that of Haplogroup 3 negatively correlated to mean temperature of January in the year of trapping. Synthesis of the published pan-European data on the species phylogeography also showed that the possibly 'thermophilous' Haplogroup 1 has the westernmost occurrence, whereas the more 'cold-resistant' Haplogroup 3 occurs much further to north-east than the other haplogroups. The observed patter may be a byproduct of the tight coevolution with nuclear genes, as we have earlier found that − in mice population in NE Poland − the spatial pattern of nuclear DNA was best explained by January temperature. Alternatively, the observed association of mitochondrial genetic variation with temperature is possible to be adaptive as cytochrome b is involved in the process of ATP production via oxidative phosphorylation.

Range Extension and State Record for Melanoplus punctulatus (Scudder) (Acrididae) in Northeastern Wyoming

Melanoplus punctulatus (Scudder) is a woodland-associated grasshopper that has been mostly recorded from the eastern U.S. and adjacent Canada. Prior to the past decade, the known westernmost occurrence of this species extended into the eastern third of South Dakota, Nebraska, Kansas, Oklahoma, and Texas. In the past decade M. punctulatus has been found at several sites in the Pine Ridge area of northwestern Nebraska. In 2018, a specimen of M. punctulatus was found at Devils Tower in northeastern Wyoming, which extends the known range of this species by 250 km and represents a state record for Wyoming. This range extension supports the idea that this is a species that may be more widespread than is realized, but is often overlooked due to its arboreal habits and cryptic coloration.

Long-term survival and successful conservation? Low genetic diversity but no evidence for reduced reproductive success at the north-westernmost range edge of Poa badensis (Poaceae) in Central Europe

Many steppe species reach their (north)westernmost distribution limit in western Central Europe. This also applies to Poa badensis, a rare steppe plant of calcareous rock/sand vegetation. To explore potential differences in reproductive success and genetic composition of peripheral populations, we analysed the absolute (north)westernmost occurrences in Western Germany and populations at the western margin (Eastern Austria) and the centre (Central Hungary) of the Pannonicum, representing a part of the continuous range. Specifically, we discuss the genetic and reproductive constitution of the (north)westernmost exclave and draw conclusions on the species’ biogeographical and conservation history in this region. Therefore, we used two independent molecular marker systems (AFLPs, cpDNA sequences) and a set of performance parameters. Overall, lowest regional genetic diversity was found in Western Germany, which is mainly a result of the specific history of two populations. However, this low genetic diversity was not accompanied by reduced reproductive success. The Eastern Austrian populations showed reduced genetic diversity and predominantly reduced performance, interpreted as a consequence of small population sizes. Central Hungarian populations showed the overall highest genetic diversity and comparatively high performance values. We observed high admixture and haplotype sharing between Austrian and Hungarian populations, indicating gene flow among these regions. In contrast, we interpreted the increased population differentiation within, and the clear distinctiveness of the German exclave as a long-term isolation of these (north)westernmost occurrences. Our results, overall, prove the good constitution of these populations and, together with their particular biogeographical history, highlight their conservation value.

Ruminantia from the middle Miocene of the Gračanica coalmine (Bugojno Basin, Bosnia-Herzegovina)

Five different ruminant taxa were found in the Gracanica coal mine: the tragulid Dorcatherium vindebonense, a palaeomerycid (Palaeomerycidae gen. et sp. indet.), the giraffe Giraffokeryx sp., and the bovids ?Tethytragus sp. and Eotragus ?clavatus. The ruminant fauna fits well to an early middle to middle middle Miocene age and is typical for a locality of the mammal units MN5 or MN6. The assemblage shows Asian as well as European affinities, represents the westernmost occurrence of Giraffokeryx known so far, and confirms the role of the Balkan Peninsula as a corridor between the two continents. As the ruminant assemblage from Gracanica is not abundant, palaeoecological considerations are only tentative, but the determined taxa point to a predominantly forested environment.

Westernmost occurrence of the dusky spinefoot Siganus luridus (Osteichthyes, Siganidae) along North African coasts

A specimen of dusky spinefoot Siganus luridus (Ruppel, 1829) was recorded in the peri-Mediterranean Lagoon of Bizerte located in northern Tunisia. This record constitutes the northernmost extension range of the species in the Tunisian waters, and the second record of a teleost Lessepsian species, known to date in a restricted brackish area. The specimen is described including morphometric measurements and meristic counts. Additionally, the distribution of S. Luridus , herbivorous species, in the Lagoon of Bizerte, the Tunisian waters in the area and in the Mediterranean Sea is commented and discussed.

New distribution records of the savanna specialist fungus-farming ant Cyatta Sosa-Calvo et al. (Hymenoptera: Formicidae: Myrmicinae).

BackgroundThe fungus-farming ant genus Cyatta (Formicidae: Myrmicinae) is represented by a single species, C. abscondita Sosa-Calvo et al., known from a few localities in Brazil (in the states of Ceará, Minas Gerais, São Paulo and the Distrito Federal), and a single locality in the Misiones province, Argentina. Cyatta is known to occur predominantly in savanna habitats and occasionally in the transition zones between the Atlantic Forest and Cerrado.New informationThe new records reported here significantly expand the previously known distribution of Cyatta abscondita and provide further support for the intimate relation between this species and the savannas of South America. We report the first occurrence of the genus in southern Brazil (Paraná state) and the westernmost occurrence (Bolivia) of Cyatta abscondita, which extend its distribution approximately 1450 km to the west. Finally, we discuss the importance of mapping inconspicuous species in order to develop strategies for protecting endangered areas and to increase our understanding of the evolutionary history of organisms and biomes.

First mammal species identified from the Upper Cretaceous of the Rusca Montană Basin (Transylvania, Romania)

Multituberculate mammals are scarce in the Late Cretaceous of Europe, being recorded exclusively from the Maastrichtian terrestrial deposits of the Haţeg and Transylvanian basins, in Romania. Moreover, they all belong to the endemic and primitive cimolodontan family Kogaionidae. Here, we report multituberculate teeth originating from the Maastrichtian fluviatile sediments of the Rusca Montană Basin (Occidental Carpathians, Poiana Ruscă Mountains). This is the westernmost occurrence of these Cretaceous mammals in Romania. These teeth are assigned to Barbatodon oardaensis, the smallest Cretaceous kogaionid species. This study presents the first occurrence of this species outside the Metaliferi sedimentary area (southwestern Transylvania, Romania). The distribution of Romanian Maastrichtian kogaionids is also discussed.

The Giraffidae of Maragheh and the identification of a new species of Honanotherium

Giraffids were important components of the late Miocene Maragheh mammalian community. We provide detailed cranial and post-cranial morphological descriptions of six Maragheh giraffids, including Helladotherium duvernoyi, Alcicephalus neumayri, Samotherium boissieri, Samotherium major, Palaeotragus coelophrys and Bohlinia attica, extending the geological range of several taxa. We also describe a new species of Honanotherium (Honanotherium bernori), a taxon smaller than Honanotherium schlosseri. This is the westernmost occurrence of Honanotherium. We create our giraffid faunal list by first identifying each Maragheh specimen to a species, creating a representative specimen/species list. Subsequently, each specimen is described by comparing the Maragheh elements with the corresponding specimens from the type locality where each species is originally known. This method allows for accurate species identifications, and facilitates palaeoecological comparisons between multiple localities using morphological differences in the taxa. For palaeoecology, we evaluate and analyse the dentition of a few adult Maragheh giraffids using combined inner and outer mesowear variables, and find individuals spanning the dietary continuum, but with a polarity towards browsing diets. We describe limb differences among the Palaeotraginae, describe dental and limb similarities between Helladotherium duvernoyi and species of Bohlininae, and discuss the ossicones of Bohlininae. We provide comprehensive and detailed anatomical descriptions of seven giraffid taxa that can facilitate future species identifications and comparisons.

The westernmost occurrence of <i>Gnathorhiza</i> in the Triassic, with a discussion of the stratigraphic and palaeogeographic distribution of the genus

Abstract. The paper refines the taxonomic assignment of the only representative of the dipnoan genus Gnathorhiza from the Lower Triassic of Poland. It is assigned here to Gnathorhiza otschevi on the basis of morphological and biometrical similarity with the tooth plates from coeval strata of the European part of Russia. The material is comprised solely of tooth plates, both the upper and the lower ones. It comes from karst deposits of the Czatkowice 1 locality (southern Poland) dated to late Olenekian, Lower Triassic. The presence of G. otschevi in southern Poland widens its palaeobiogeographic Triassic record by more than 2000 km to the west. Czatkowice 1 locality is the only known occurrence of gnathorhizids within the Germanic Basin. G. otschevi from Czatkowice 1 shows petrodentine in the tooth plate. Its presence is proved for the first time in a Triassic gnathorhizid. Gnathorhiza was most widely distributed during the Permian and restricted to Europe in the Triassic. Tooth plates of both Early Triassic European and Late Permian Brazilian gnathorhizids are more similar to each other than to Permo-Carboniferous American ones.

Early Permian (Asselian) vegetation from a seasonally dry coast in western equatorial Pangea: Paleoecology and evolutionary significance

The Pennsylvanian–Permian transition has been inferred to be a time of significant glaciation in the Southern Hemisphere, the effects of which were manifested throughout the world. In the equatorial regions of Pangea, the response of terrestrial ecosystems was highly variable geographically, reflecting the interactions of polar ice and geographic patterns on atmospheric circulation. In general, however, there was a drying trend throughout most of the western and central equatorial belt. In western Pangea, the climate proved to be considerably more seasonally dry and with much lower mean annual rainfall than in areas in the more central and easterly portions of the supercontinent. Here we describe lower Permian (upper Asselian) fossil plant assemblages from the Community Pit Formation in Prehistoric Trackways National Monument near Las Cruces, south-central New Mexico, U.S.A. The fossils occur in sediments within a 140-m-wide channel that was incised into indurated marine carbonates. The channel filling can be divided into three phases. A basal channel, limestone conglomerate facies contains allochthonous trunks of walchian conifers. A middle channel fill is composed of micritic limestone beds containing a brackish-to-marine fauna with carbon, oxygen and strontium isotopic composition that provide independent support for salinity inferences. The middle limestone also contains a (par)autochthonous adpressed megaflora co-dominated by voltzian conifers and the callipterid Lodevia oxydata. The upper portions of the channel are filled with muddy, gypsiferous limestone that lacks plant fossils. This is the geologically oldest occurrence of voltzian conifers. It also is the westernmost occurrence of L. oxydata, a rare callipterid known only from the Pennsylvanian–Permian transition in Poland, the Appalachian Basin and New Mexico. The presence of in situ fine roots within these channel-fill limestone beds and the taphonomic constraints on the incorporation of aerial plant remains into a lime mudstone indicate that the channel sediments were periodically colonized by plants, which suggests that these species were tolerant of salinity, making these plants one of, if not the earliest unambiguous mangroves.

島根県隠岐諸島島後の中新統久見層および都万層の珪藻化石層序

A biostratigraphic study of fossil diatoms revealed that the most of the Kumi Formation in Dogo, Oki Islands, is correlative with the Crucidenticula kanayae Zone to Thalassiosira yabei Zone, and that the Tsuma Formation with the Rouxia californica Zone to lower Neodenticula kamtschatica Zone, respectively. On the other hand, the lowermost of the Kumi Formation yielded a Lower Miocene freshwater planktonic diatom assemblage. The assemblage mainly consists of various forms of the genus Auracoseira associated with lacustrine Actinocyclus species. It is overlain by the marine Kumi Formation correlated to, or lower than, the Lower Miocene Crucidenticula kanayae Zone (16.6-17.0 Ma) which evidences that the geologic section recorded the first marine water invasion related to the Japan Sea opening in the area. This abrupt change of the diatom assemblage from freshwater to marine planktons suggests the rapid transgression in the area where wide continental shelf did not develop. In addition, this study shows the first discovery of the biostratigraphic index diatom fossil N. kamtschatica from the Tsuma Formation which is the westernmost occurrence from the Japan Sea side.

The puzzle assembled: Ediacaran guide fossil Cloudina reveals an old proto-Gondwana seaway

ABSTRACTDuring the Ediacaran the Clymene Ocean separated the Lau-rentia, Amazonia, and Rio Apa cratons from several landmasses to the west forming the proto-Gondwana supercontinent. However, no clear evidence about the existence of Ediacaran epeiric seas over those landmasses has been found. Here we report and discuss the discovery of the Ediacaran guide fossil Cloudina sp. associated with other metazoan body and trace fossils in the Bambui Group (central eastern Brazil). The Ediacaran age of the Bambui Group and the paleogeographic position of Cloudina -bearing successions in Brazil, Antarctica, Namibia, and Argentina suggest a scenario of ocean con-nectivity among coeval intracratonic basins of South America, Africa, and Antarctica at the end of Neoproterozoic time. The new fi nding epitomizes one of the most important paleontological discoveries ever made in South America, helping to solve an old paleogeographic puz-zle of the Gondwana supercontinent.INTRODUCTION The Bambui Group crops out in central eastern Brazil, and is one of the most studied Neoproterozoic sedimentary successions in South America. It comprises an extensive, fl at-lying cratonic cover in erosional contact with Paleoproterozoic and Archean basement rocks of the Sao Francisco craton. In its eastern and westernmost occurrences, the Bam-bui Group is deformed and metamorphosed by the Brasilia and Aracuai mobile belts, respectively (Fig. 1A). The regional tectonostratigraphy has been interpreted as refl ecting deposition in a foreland basin related to Gondwanan collisions involving the Sao Francisco craton (Pimentel et al., 2011).The Bambui Group (BG) overlies rocks of the Macaubas Group and Jequitai Formation and the Carrancas conglomerate, units supposedly de-posited during Sturtian glaciation. The unit is 700–1000 m thick (Misi et al., 2007) and comprises limestones and dolomites of the Sete Lagoas For-mation at the base that grade upward to shales and siltstones of the Serra de Santa Helena Formation, followed by marls, siltstones, limestones, and sandstones of the Lagoa do Jacare, Serra da Saudade, and Tres Marias Formations (Fig. 1B).The precise age of the BG is not well established, precluding accurate correlation with other supposedly coeval successions such as the Corumba Group (Brazil), Itapucumi (Paraguay), Arroyo del Soldado (Uruguay), Si-erras Bayas (Argentina), and Nama Group (Namibia). The presence of

New Early Triassic coelacanth in the family Laugiidae (Sarcopterygii: Actinistia) from the Sulphur Mountain Formation near Wapiti Lake, British Columbia, Canada

A new Early Triassic coelacanth, Belemnocerca prolata, gen. et sp. nov., is described as a new member of the family Laugiidae. Although only one incomplete specimen is known, much can be deduced about its evolutionary relationships. In particular, the new coelacanth is most similar to one member of its family, Laugia groenlandica, in the asymmetry (dorsal lobe longer than ventral) and the gradually tapering shape of its caudal fin, though it differs in caudal fin ray count and anal fin position as well as in the size and shape of the supplementary lobe. Belemnocerca prolata is the westernmost occurrence of the family Laugiidae and only member of this family known to inhabit Panthalassa, west of the supercontinent Pangaea. The family Laugiidae has a temporal range from the Early Triassic to the Late Jurassic, and its members have been described from both Greenland and Germany.

A New Plesiosauroid from the Toarcian (Lower Jurassic) of Alhadas, Portugal

A partial plesiosauroid skull from the Sao Giao Formation (Toarcian, Lower Jurassic) of Alhadas, Portugal is re-evaluated and described as a new taxon, Lusonectes sauvagei gen. et sp. nov. It has a single autapomorphy, a broad triangular parasphenoid cultriform process that is as long as the posterior interpterygoid vacuities, and also a unique character combination, including a jugal that contacts the orbital margin, a distinct parasphenoid—basisphenoid suture exposed between the posterior interpterygoid vacuities, lack of an anterior interpterygoid vacuity, and striations on the ventral surface of the pterygoids. Phylogenetic analysis of Jurassic plesiosauroids places Lusonectes as outgroup to “microcleidid elasmosaurs”, equivalent to the clade Plesiosauridae. Lusonectes sauvagei is the only diagnostic plesiosaur from Portugal, and the westernmost occurrence of any plesiosaurian in Europe.

New records and range extensions of Astrodictyum panamense (Ophiuroidea: Gorgonocephalidae) in the eastern Pacific Ocean

The ringed basket star Astrodictyum panamense is an ophiuroid resident of coral and rocky reefs from the central and southern Gulf of California and oceanic islands from the eastern Pacific. This paper presents new records of this species obtained from fieldwork and internet sources, and includes its northernmost and westernmost occurrence in the eastern Pacific (Adair Bay, Gulf of California, and Tortugas Bay, on the Pacific side of Baja California, respectively), as well as Roca Partida Island, in the Revillagigedo Archipelago.