The callovian (Middle Jurassic) crinoids from northern Lithuania

Callovian strata in northern Lithuania (Papilė area) have yielded some crinoid taxa[Chariocrinus andreae (Desor),Balanocrinus berchteni Hess —Pugin,B. subteres (Münster inGoldfuss) andIsocrinus nicoleti (Desor)], which have not been described from this area. The only form known previously wasBalanocrinus pentagonalis (Goldfuss).Palaeocomaster jaegeri n. sp. is the first free-living crinoid recorded from the Callovian of eastern Europe. It is characterized by possessing a very low, strongly flattened and narrow radial cavity. A very similar crinoid assemblage is known from the Callovian glacially-derived clays exposed in the Łuków region (eastern Poland), which were originally located near the Baltic Sea during the Middle Jurassic. It is considered that the allochthonous Callovian deposits from Poland are facies equivalents of the deposits known from Lithuania. The sole significant exception is the domination of free-moving comatulids (Comatulida) in the sediments known from the Papilė region, which may suggest that the Lithuanian sea basin was a little shallower than that located farther west in the Baltic area.      

A New Pterosaur Tracksite from the Jurassic Summerville Formation,Near Ferron,Utah

Pterosaur tracks (cf. Pteraichnus) from the Summerville Formation of the Ferron area of central Utah add to the growing record of Pteraichnus tracksites in the Late Jurassic Summerville Formation and time-equivalent, or near time-equivalent, deposits. The site is typical in revealing high pterosaur track densities, but low ichnodiversity suggesting congregations or “flocks” of many individuals. Footprint length varies from 2.0 to 7.0 cms. The ratio of well-preserved pes:manus tracks is about 1:3.4. This reflects a bias in favor of preservation of manus tracks due to the greater weight-bearing role of the front limbs, as noted in other pterosaur track assemblages. The sample also reveals a number of well-preserved trackways including one suggestive of pes-only progression that might be associated with take off or landing, and another that shows pronounced lengthening of stride indicating acceleration.

One well-preserved medium-sized theropod trackway (Therangospodus) and other larger theropod track casts (cf. Megalosauripus) are associated with what otherwise appears to be a nearly monospecific pterosaur track assemblage. However, traces of a fifth pes digit suggest some tracks are of rhamphorynchoid rather than pterodactyloid origin, as usually inferred for Pteraichnus. The tracks occur at several horizons in a thin stratigraphic interval of ripple marked sandstones and siltstones. Overall the assemblage is similar to others found in the same time interval in the Western Interior from central and eastern Utah through central and southern Wyoming, Colorado, northeastern Arizona, and western Oklahoma. This vast “Pteraichnus ichnofacies,” with associated saurischian tracks, remains the only ichnological evidence of pre-Cretaceous pterosaurs in North America and sheds important light on the vertebrate ecology of the Summerville Formation and contiguous deposits.     

Enigmatic didactyl tracks from the Jurassic of Iran

Didactyl tracks of theropod affinity are reported in this study based on a small sample of footprints in sandstones within the Middle Jurassic (Aalenian-Bajocian) Dansirit Formation in the Baladeh area, Alborz Mountains, Iran. These tracks superficially resemble footprints attributed to small deinonychosaurian dinosaurs known mainly from the Cretaceous of Asia. The relative length of the traces of digits III and IV is atypical for deinonychosaurids, especially dromaeosaurids, but could potentially be attributed to a troodontid-like trackmaker. The possibility of small Middle Jurassic deinonychosaurian trackmakers cannot be ruled out on the basis of the age of these traces. However, reports of pre-Cretaceous tracks of deinonychosaurian or deinoychosaur-like affinity remain rare and problematic. To date previous reports of pre-Cretaceous didactyl tracks pertain to a variable range of footprint morphologies, some of which predate known deinonychosaurian body fossil occurrences.     

Middle Jurassic Flora from Shouthern Margin of Eerduosi Basin

This paper deals with some Middle Jurassic fossil plants from southern margin of the Eerduosi Basin. There are 36 species in 13 genus in this flora, i.e. Equisetum multi- dentatus Oishi, E. sp., Coniopteris hymenophylloides (Brongn.) Seward, C. bella Harris, C, burejensis (Zalessky) Seward, C. szeiana Choweet Yeh, C. tatungensis Sze, C. spp., Todites williamsoni (Brongn.) Seward, T. cf. williamsoni (Brongn.) Seward, Cladophle- bis asiatica Chow et Yeh, C. argutula (Heer) Fontaine, C. hsiehiana Sze, C. ( Gleichenites) takeyamae Oishi et Takahasi, C. cf. gracils Sze C. triangularis Oishi, C. grabauiana P’an C. cf punctata (Thoms) Chow et Yeh, C. spp., Baiera cf. concinna (Heer) Kawasaki, B. furcata (L. et H.) Braun, B. sp., Sphenobaiera longifolia (Pomel) Florin, Ginkgo obrutchewi Seward, G. sp., Phoenicopsis angustifolia Heer P. manchurica (Yo- koyama) Yabe, p. sp., Czekanowskia rigida Heer, C. sp., Pterphyllum sp., Elatocladus cf manchurica (Yokoyama) Yabe, E. sp., Podozamites lanceolatus (L. et. H.) Braun P. sp., Carpolithus sp. etc. The dominant groups of this flora are Filicopsida and Ginkgopsida. So it could be compared with the flora of Yanan Formation from inner Earduosi Basin and other floras from Northeast, Northwest and China, such as the floras of Dutung, Mentougon and Dongsheng etc. This flora is different from the Late Triassic flora and the Early Jurassic flora of North China. It belongs to the Coniopteris-Phoenicopsis flo- ra, which was assigned to Early-Middle Jurassic flora by Prof. Sze. But after studying, the authers believe that this flora should belong to Middle Jurassic rather than Early Jurassic. The climate was warm and damp in that time in North China.     

Lower limits of ornithischian dinosaur body size inferred from a new Upper Jurassic heterodontosaurid from North America

The extremes of dinosaur body size have long fascinated scientists. The smallest (<1 m length) known dinosaurs are carnivorous saurischian theropods, and similarly diminutive herbivorous or omnivorous ornithischians (the other major group of dinosaurs) are unknown. We report a new ornithischian dinosaur, Fruitadens haagarorum, from the Late Jurassic of western North America that rivals the smallest theropods in size. The largest specimens of Fruitadens represent young adults in their fifth year of development and are estimated at just 65–75 cm in total body length and 0.5–0.75 kg body mass. They are thus the smallest known ornithischians. Fruitadens is a late-surviving member of the basal dinosaur clade Heterodontosauridae, and is the first member of this clade to be described from North America. The craniodental anatomy and diminutive body size of Fruitadens suggest that this taxon was an ecological generalist with an omnivorous diet, thus providing new insights into morphological and palaeoecological diversity within Dinosauria. Late-surviving (Late Jurassic and Early Cretaceous) heterodontosaurids are smaller and less ecologically specialized than Early (Late Triassic and Early Jurassic) heterodontosaurids, and this ecological generalization may account in part for the remarkable 100-million-year-long longevity of the clade.     

The native subspecies of Juncus effusus (Juncaceae) in western North America

Juncus effusus s. str. has two native representatives on the coast of western North America. A new combination is provided forJuncus effusus subsp.pacificus, ranging from California to British Columbia.Juncus effusus subsp.austrocalifornicus is newly described from southernmost California, Arizona, and Baja California, México. It differs from subsp.pacificus by its pale sheaths, with less thickened and less overlapping margins, and its disjunct distribution. A key is provided for the subspecies ofJ. effusus in North America.     

Cyrtocrinids (Echinodermata,Crinoidea) from Upper Jurassic Štramberk‐type limestones in southern Poland

Abstract: A systematic account of highly diverse cyrtocrinid faunules from Upper Jurassic strata of ?tramberk type (Oxfordian–Tithonian) in southern Poland (Polish Carpathians) is presented. Fourteen taxa (Phyllocrinus malbosianus, Ph. stellaris, Ph. sp., Psalidocrinus armatus, Sclerocrinus compressus, S. polonicus sp. nov., Hemicrinus aff. kabanovi, Ancepsicrinus parvus gen. et sp. nov., Tetracrinus baumilleri sp. nov., Eugeniacrinites alexandrowiczi, E. cf. moravicus, E. sp., Eudesicrinus gluchowskii sp. nov. and Hemibrachiocrinus tithonicus sp. nov. are described and illustrated. Representatives of the genus Eudesicrinus, previously recorded only from the Lower Jurassic, are here shown to extend into the uppermost Jurassic. Other cyrtocrinids considered are common in Jurassic/Cretaceous strata across Europe. In the present faunules, isocrinid (Isocrinida), comatulid (Comatulida) and roveacrinid (Roveacrinida sensu Rasmussen, inclusive of Saccocoma) crinoids are associated.     

Ichnofossils of the Psilonichnus Ichnofacies and Their Paleoecological and Paleoenvironmental Significance in the Scottish Middle Jurassic

In the Bathonian (Middle Jurassic) Kilmaluag Formation, Great Estuarine Group, on the Isle of Skye, northwest Scotland, are ichnofossils that can be attributed to the burrowing activity of semi-terrestrial crab-like animals. The ichnofossils are preserved within supralittoral breccia-conglomerates and littoral calcareous mudstones and micrites deposited in a closed and shallow, low-salinity to freshwater coastal-lagoon setting. The dominant ichnofossil assemblage is preserved in the supralittoral rocks and comprises variable burrow types forming an ichnocoenosis and assigned to the Psilonichnus ichnofacies. These ichnofossils potentially provide the earliest known record of crab activity and their physiological adaptation to survive in a semi-terrestrial environment. Burrow characteristics include enlarged funnel-shaped apertures, unlined walls, absence of branching or biogenic reworking, inclined to vertical, U- and L-shaped forms and possible basal dwelling chamber. The ichnofossil assemblage preserved in the littoral rocks is attributed to the activity of either semi-terrestrial crabs or shrimps. Ichnofaunal characteristics reveal unique aspects of the paleoenvironments and paleoecology of the tracemaking community, including climatic conditions, substrate characteristics, the possible influence of paleowater table levels, paleoshoreline position, spatial variation in burrow morphology and possible gregarious and territorial behavior.     

Morphology and microstructure of Pellites hamiensis nov. sp., a Middle Jurassic liverwort from northwestern China and its evolutionary significance

Pelliales is a basal lineage of the simple thalloid liverworts. Here, we describe a simple thalloid liverwort from the Middle Jurassic Xishanyao Formation of the Turpan–Hami Basin, Xinjiang Uygur Autonomous Region in northwestern China. The thalloid fossil liverwort is described as a new species: Pellites hamiensis (Pelliaceae, Pelliales). Pellites hamiensis nov. sp. resembles the extant species of Pelliaceae in having ribbon-like segments, conspicuous costae that appear as ridges on the ventral surface, rectangular cells with thickened walls adjacent to the margin, and elongated cells in the middle part of the thallus. The occurrence of P. hamiensis nov. sp. extends the fossil records of Pellites back to the Aalenian-Bajocian or Bajocian (ca. 170 Ma) and suggests that the divergence time of the Pelliaceae is no later than the Middle Jurassic.     

陕西子洲中侏罗世早期恐龙足迹初步研究

陕西子洲县中侏罗统延安组砂岩中,同一地点共厚约1.7 m的5个层面发现4种食肉类恐龙足迹,自上而下分别为:1)第5层面大型三趾型足迹,实雷龙足迹科王氏子洲足迹(新遗迹属、新遗迹种)Zizhoupus wangi ichnogen.et ichnosp,nov.;2)第4和第3层面中型三趾型足迹,实雷龙足迹科龙尾峁张北足迹(新遗迹种)Changpeipus longweimaoensis inchnosp.nov.;3)第2层面小型三趾或四趾型足迹,虚骨龙类小理河陕西足迹(新遗迹种)Shensipus xiaoliheensis inchnosp.nov.;4)第1层面小型三趾型足迹,虚骨龙类的铜川陕西足迹Shensipus tungchuanensis.     

New Middle Jurassic record of fern genus Eboracia (Dicksoniaceae,Filicales) and its spatio-temporal distribution in China

As an important component of the Mesozoic flora, the extinct fern genus Eboracia Thomas (Dicksoniaceae, Filicales) is widely reported in China with diverse fossil records. New material of Eboracia lobifolia, represented by a nearly intactly preserved fossil frond, is described herein from the Middle Jurassic Haifanggou Formation in Beipiao of western Liaoning, Northeast China. The frond is lanceolate in gross outline, at least 38.0 cm long, and can be divided into the basal sterile part, the upper fertile part and a transitional part in between. The new discovery confirms for the first time that the frond of E. lobifolia is hemidimorphic rather than holodimorphic. Many in-situ spores were detached from the sori of the fertile pinnae, which are characterized by rounded-tetrahedral shape, smooth surface, distinct border, and a wide, long triradiate crack almost reaching the equator. Comparing with dispersed spores in the same horizon, these in-situ spores seem to be most similar to Cyathidites minor Couper in morphology. A spatio-temporal analysis of Eboracia in China shows that Eboracia with totally four species occurred in a time interval ranging from the Late Triassic to the Early Cretaceous in China, and mostly flourished in the Middle Jurassic; the genus was widely distributed in both the Northern and Southern Phytofloristic Provinces of China, particularly in southern China during the Late Triassic to Early Jurassic, while more abundant and diverse in northern China during the Middle Jurassic to Early Cretaceous.     

New ommatids from the Late Jurassic of western Liaoning, China （Coleoptera： Archostemata）

A new genus Amblomma gen. nov. of fossil beetles is erected and can be assignedto the family Ommatidae because its two procoxal cavities are contiguous and the articulations of the abdominal ventrites are abutting. The new genus is similar to Zygadenia Handlirsch, 1906 (=Notocupes Ponomarenko, 1964), Tetraphalerus Waterhouse, 1901,Rhobdocupes Ponomarenko, 1966 and Sinocupes Lin, 1976, but can be distinguished from other genera according to the following characters: the second segment of antennae is shorterthan the third one in length; the posterior tarsi with the basal segment is obviously shorter than the three following taken together in length; the antennae reach the posterior ridge of prothroax in length, and the sides of the prothroax with serrulate margin. Four new species of the new genus are described and figured: Amblomma psilata gen. et sp. nov., Amblomma rudis gen. et sp. nov., Amblomma epicharis gen. et sp. nov., and Amblomma stabilis gen. etsp. nov. A key to species within this new genus is provided. All the specimens are collected from the Late Jurassic Yixian Formation of western Liaoning and are now housed in the College of Life Science, Capital Normal University, Beijing, China.     

Brachiopod palaeobiogeography in the western Tethys during the Early Jurassic diversity maximum: introduction of a Pontic Province

The biogeography of Pliensbachian (Early Jurassic) brachiopods in western Tethys is investigated using complementary multivariate tools including metric and non-metric ordination, additive cluster and bootstrapped spanning network analyses, as well as one-way analysis of similarity and similarity percentage analysis. All analyses were conducted using the Dice and Simpson similarity indices for presence/absence data on occurrence datasets involving 24 assemblages homogenized at the species level, including (403 taxa) or excluding (210 taxa) species found in only one assemblage. The analyses present a highly consistent biogeographical picture involving three main clusters: the Euro-Boreal, Mediterranean and Pontic biochores. The brachiopod species typical of the newly defined Pontic biochore are illustrated. The three assemblages from the Atlas area are interpreted as a fourth biochore, compositionally intermediate between those of the Euro-Boreal and Mediterranean. The Mediterranean biochore can be further divided into an intra- and a peri-Mediterranean group. These five, palaeogeographically well-constrained biochores show moderate to high degrees of species endemicity, ranging from 20% (Atlas) to 58% (Euro-Boreal). Based on available evidence, and after a reasonable cutback of the customary scale of ranks, the following biogeographical categories and names are suggested for the western Tethyan Pliensbachian brachiopod biochores: Euro-Boreal Province, Mediterranean Province (including an intra-Mediterranean and a peri-Mediterranean Subprovince), Pontic Province and Atlas Subprovince. In addition, a still poorly documented brachiopod biochore occurs on the Gondwana margin as a possible precursor of the extensive Middle to Late Jurassic Ethiopian Province.     

New fossil hangingflies (Insecta: Mecoptera: Raptipedia: Cimbrophlebiidae) from the Middle Jurassic of Inner Mongolia,China

Abstract: Two new genera with six new species of hangingflies (Mecoptera: Raptipedia: Cimbrophlebiidae) are described. They were collected from the Middle Jurassic nonmarine sedimentary strata of the Jiulongshan Formation in Daohugou, Inner Mongolia, north‐eastern China. This report of Cimbrophlebiidae from the Yanliao Biota provides detailed morphological information and evidence of a broad diversity of Cimbrophlebiidae during the Middle Jurassic. A key to the known species of Cimbrophlebiidae is provided.     

陕西彬县地区中侏罗世延安组孢粉植物群及其意义

报道了采自陕西彬县地区中侏罗世延安组的孢粉化石６０属,８３种。经研究表明,陕西彬县地区延安组的孢粉组合是以裸子植物花粉为主,蕨类植物孢子次之。银杏、苏铁类和松柏类花粉在组合中占优势;桫椤科孢子在蕨类中具有较高的含量。根据孢粉组合特征及其对比,延安组的时代应属中侏罗世早期。陕西彬县地区当时的植被是以银杏、苏铁类和松柏类等乔木为主,并伴有桫椤科为主体的树蕨植物及草本植物,古气候应属大陆性亚热带气候。     

Intracolonial variability in new bryozoans from the Middle Jurassic of the Bryansk Region (Russia)

Two new species of encrusting bryozoans (Stenolaemata, Tubuliporida) from the Middle Callovian (Middle Jurassic) deposits of the Bryansk Region, Oncousoecia guzhovi sp. nov. and Microeciella fokinensis sp. nov., are described. Their intracolonial variability, which is due to differences in astogenetic stages and to external factors, is discussed.     

Small Theropod Track Assemblages from Middle Jurassic Eolianites of Eastern Utah: Paleoecological Insights from Dune Ichnofacies in a Transgressive Sequence

New discoveries show that very small theropod tracks (cf. Wildeichnus) are abundant in the upper part of the Moab Member, recently assigned to the Curtis Formation (formerly considered part of the Entrada Formation) in the Mid-?Late Jurassic of eastern Utah. The tracks represent a distinct small-theropod ichnofacies associated with eolian dune deposits that is easily differentiated from the water-lain beds of the overlying Megalosauripus-Therangospodus ichnofacies, which comprises the single-surface Moab megatracksite. Pterosaur track assemblages, representing the Pteriachnus ichnofacies, are found a few meters above the megatracksite surface in the upper tongue of the Summerville Formation.

The small theropod ichnofacies is reminiscent of other early Mesozoic dune facies ichnofaunas from the Wingate and Navajo formations (Late Triassic and Early Jurassic) where small theropod tracks occur in association with other small tetrapod footprints. All such examples evidently represent a recurrent dune facies ecosystem dominated by diminutive vertebrates. Because the small theropod ichnofacies is one of three ichnofacies found in a thin stratigraphic sequence (<20 m) that contains no body fossils, it is clear that vertebrate tracks play an important role in providing insight into the paleoecology of units previously considered devoid of any useful fossil evidence. The three successive ichnofacies represent a transgressive transition from sand dunes, through sandy shoreline to shallow marine environments, each with its quite distinct vertebrate fauna.     

A lower jaw of Palaeoxonodon from the Middle Jurassic of the Isle of Skye,Scotland, sheds new light on the diversity of British stem therians

The Middle Jurassic was a key interval of mammalian evolutionary history that witnessed the diversification of the therian stem group. Great Britain has yielded a significant record of mammalian fossils from this interval, represented by numerous isolated jaws and teeth from the Bathonian of Oxfordshire and the Isle of Skye. This record captures a key period in early cladotherian evolution, with amphitheriids, peramurans and ‘stem zatherians’ displaying intermediate talonid morphologies that document the evolutionary assembly of tribosphenic molars. We present a mandible with near‐complete dentition from the late Bathonian (c. 167.4–166.5 Ma) Kilmaluag Formation, near Elgol, Skye, representing the amphitheriid Palaeoxonodon ooliticus, previously known only from isolated teeth. The specimen sheds new light on the taxonomic diversity of British Middle Jurassic stem therians, as the morphological variation within the preserved tooth row encompasses that previously ascribed to three distinct species within two genera: Palaeoxonodon ooliticus, P. freemani and Kennetheridium leesi. Thus, both P. freemani and K. leesi are subjective junior synonyms of P. ooliticus. The dental formula of P. ooliticus (i4:c1:p5:m5) is intermediate between the primitively larger postcanine count (p5:m6–7) of Amphitherium and the reduced number in peramurans and tribosphenidans (p5:m3). Phylogenetic analyses of P. ooliticus generally confirm a close affinity with Amphitherium, but highlight the lack of strong empirical support for hypothesized patterns of divergences among early cladotherians.     

湖北秭归盆地中侏罗世陈家湾组孢粉组合的发现及其意义

本文首次报道了湖北秭归盆地陈家湾组孢粉组合,该组合可归入Cyathidites minor-Classopollis Callialasporites为代表的组合,时代属中侏罗世。陈家湾组孢粉组合的特征反映了秭归盆地中侏罗世泄滩组、陈家湾组和沙溪庙组三个组的孢粉组合的面貌基本一致,仅早期组合与中、晚期组合略有差别。建议以Gyathidites minor-classopollis-callialasportes组合代表湖北西部——重庆地区中侏罗世孢粉组合,早期为Lunzisporites pallidus亚组合,中晚期为Converrrcosisporites venitus亚组合。根据孢粉植物群在本区侏罗纪垂直分布情况,提出早侏罗世时期属亚热带一热带炎热潮湿气候环境,植物生长茂盛;早侏罗世之后,潮湿的气候仍占主导地位,但出现了干旱的先兆;中侏罗世早期进入了半干旱阶段,随后即为炎热干旱的气候所笼罩;至晚侏罗世达到非常干旱的程度,植物种类十份单调,唯有掌鳞杉科植物占据着统治地位。